U.S. patent application number 16/270214 was filed with the patent office on 2020-02-06 for semiconductor device and method of manufacturing the same.
The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to YOUNG-HUN KIM, HAE-WANG LEE, JAE-SEOK YANG.
Application Number | 20200043945 16/270214 |
Document ID | / |
Family ID | 69227577 |
Filed Date | 2020-02-06 |
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United States Patent
Application |
20200043945 |
Kind Code |
A1 |
KIM; YOUNG-HUN ; et
al. |
February 6, 2020 |
SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME
Abstract
A semiconductor device includes a substrate having cell areas
and power areas that are alternately arranged in a second
direction. Gate structures extend in the second direction. The gate
structures are spaced apart from each other in a first direction
perpendicular to the second direction. Junction layers are arranged
at both sides of each gate structure. The junction layers are
arranged in the second direction such that each of the junction
layer has a flat portion that is proximate to the power area.
Cutting patterns are arranged in the power areas. The cutting
patterns extend in the first direction such that each of the gate
structures and each of the junction layers in neighboring cell
areas are separated from each other by the cutting pattern.
Inventors: |
KIM; YOUNG-HUN; (SEOUL,
KR) ; YANG; JAE-SEOK; (HWASEONG-SI, KR) ; LEE;
HAE-WANG; (YONGIN-SI, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
SUWON-SI |
|
KR |
|
|
Family ID: |
69227577 |
Appl. No.: |
16/270214 |
Filed: |
February 7, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 2027/11881
20130101; H01L 2027/11861 20130101; H01L 27/0207 20130101; H01L
2027/11874 20130101; H01L 27/11807 20130101; H01L 2027/11829
20130101; H01L 21/823871 20130101; H01L 21/823814 20130101; H01L
21/823878 20130101; H01L 2027/11864 20130101 |
International
Class: |
H01L 27/118 20060101
H01L027/118; H01L 21/8238 20060101 H01L021/8238; H01L 27/02
20060101 H01L027/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 2, 2018 |
KR |
10-2018-0090472 |
Claims
1. A semiconductor device, comprising: a substrate including a
plurality of cell areas and a plurality of power areas such that
each of the plurality of cell areas are alternately arranged with
each of the plurality of power areas, in a second direction; a
plurality of gate structures extending in the second direction,
each of the plurality of gate structures being spaced apart from
each other in a first direction that is substantially perpendicular
to the second direction; a plurality of junction layers arranged at
both sides of each of the plurality of gate structures and arranged
in the second direction in such a configuration that each of the
plurality of junction layer has a flat portion that is proximate to
the power area; and a plurality of cutting patterns arranged in the
plurality of power areas and extending in the first direction such
that each of the plurality of gate structures and each of the
plurality of junction layers in neighboring cell areas of the
plurality of cell areas are separated from each other by the
cutting pattern.
2. The semiconductor device of claim 1, wherein each oaf the
plurality of junction layers includes an epitaxial layer grown in
the second direction from a plurality of active fins extending in
the first direction such that the epitaxial layer is largest around
each of the plurality of power areas.
3. The semiconductor device of claim 2, wherein the epitaxial layer
includes a point portion that is spaced apart horn each of the
plurality of power areas.
4. The semiconductor device of claim 1, further comprising: a power
rail extending in the first direction on the cutting pattern and to
which a power signal is applied; and a contact structure in contact
with the power rail and the plurality of junction layers and
configured to transfer the power signal to the plurality of
junction layers from the power rail.
5. The semiconductor device of claim 4, wherein the contact
structure includes: a cell contact that is in contact with the
junction layer in the cell area: and a power contact arranged at a
side of the cutting pattern, in contact with the flat portion of
each of the plurality of junction layers and the power rail.
6. The semiconductor device of claim 5, wherein the cutting pattern
includes a gate cutting pattern directly contacting each of the
plurality of gate structures and having a first width, and a
junction cutting, pattern that is spaced apart from the flat
portion of each of the plurality of junction layers by a second
contact bole and having a second width smaller than the first
width, the gate cutting pattern and the junction cutting pattern
being arranged alternately with each other in the first
direction.
7. The semiconductor device of claim 6, wherein the power contact
is arranged in the second contact hole such that a bottom surface
of the power contact is in contact with a device isolation layer
and a side surface of the power contact is in contact with the flat
portion of each of the plurality of junction layers.
8. The semiconductor device of claim 1, wherein each of the
plurality of cell areas includes a PMOS area in which at least one
p-type MOS transistor is arranged, an NMOS area in which at least
one n-type MOS transistor is arranged, and a separation area
interposed between the PMOS area and the NMOS area and separating
the PMOS area and the NMOS area from each other, wherein the
cutting pattern includes a nitride.
9. The semiconductor device of claim 8, further comprising a
separation pattern disposed on the separation area of each of the
plurality of cell areas such that the plurality of gate structures
and the plurality of junction layers in the NMOS area are separated
from the plurality of gate structures and the plurality of junction
layers in the PMOS area.
10. The semiconductor device of claim 9, wherein the separation
pattern is arranged across at least one gate structure of the
plurality of gate structures and at least one junction layer of the
plurality of junction layers, in the first direction.
11. The semiconductor device of claim 10, wherein the separation
pattern includes a same material as the cutting pattern.
12. A method of manufacturing a semiconductor device, comprising:
forming a plurality of active fins in at least a pair of cell areas
extending in a first direction, the pair of cell areas being
separated from each other by a power area; forming a plurality of
dummy gate structures and a plurality of gap fill patterns to a
line shape extending in a second direction, substantially
perpendicular to the first direction, such that each of the
plurality of dummy gate structures and each of the plurality of gap
fill patterns covers the plurality of active fins, alternately with
respect to each other in the first direction, forming a cutting
pattern in the power area in a line shape extending in the first
direction such that the plurality of dummy gate structures and the
plurality of gap fill patterns are separated from each other by a
unit of a cell area of the at least the pair of cell areas; and
forming a junction layer in a gap space between neighboring dummy
gate structures, of the plurality of dummy gate structures, such
that the junction layer makes contact with the plurality of active
fins in the at least the pair of cell areas and has a flat portion
making contact with the cutting pattern.
13. The method of claim 12, wherein forming the cutting pattern
includes: partially removing each of the plurality of dummy gate
structures, a gate spacer on side surfaces of each of the plurality
of dummy gate structures and each of the plurality of gap fill
patterns from the power area, thereby forming a cutting trench
through which a device isolation layer is exposed; forming a
cutting layer on each of the plurality of dummy gate structures,
the gate spacer and each of the plurality of gap fill patterns and
the device isolation layer to a thickness for filling the cutting
trench; and planarizing the cutting layer until upper surfaces of
each of the plurality of dummy gate structures, the gate spacer and
each of the plurality of gap till patterns, so that the cutting
layer remains exclusively in the cutting trench.
14. The method of claim 13, wherein the cutting pattern includes
silicon nitride (SiN), silicon oxynitride (SiON), and/or silicon
carbon oxynitride (SiOCN).
15. The method of claim 13, wherein forming the junction layer
includes: removing each of the plurality of gap fill patterns from
the at least the pair of cell areas, thereby forming an
inter-spacer hole defined by neighboring gate spacers of the
plurality of dummy gate structures and the cutting pattern and
through which the plurality of active fins and the device isolation
layer are exposed; and conducting a selective epitaxial growth
(SEG) process using the plurality of active fins as a seed such
that the junction layer is horizontally grown to the cutting
pattern in the second direction and is vertically grown along a
side surface of the cutting pattern in a third direction
substantially perpendicular to the first and the second directions
to thereby form the flat portion making contact with the cutting
pattern.
16. The method of claim 15, wherein an upper portion of each of the
plurality of active fins is removed from the inter-spacer hole in
removing the gap fill pattern to thereby form an active recess in
the inter-spacer hole, so that the junction layer is protruded into
the active recess.
17. The method of claim 12, further comprising: forming an
insulation pattern at least partially covering the junction layer;
forming a gate trench extending in the second direction in the cell
area by removing the plurality of dummy gate structures from the
cell area; forming a gate structure such that the gate trench is
tilled with the gate structure; forming a contact structure making
contact with the junction layer; and firming a power rail arranged
on the cutting pattern and extending in the first direction such
that the power rail makes contact with the contact structure.
18. The method of claim 17, wherein forming the contact structure
includes: forming a first interlayer dielectric pattern on each of
the plurality of gate structures and the cutting pattern in a line
extending in the second direction such that the insulation pattern
and the cutting pattern are exposed through the first interlayer
dielectric pattern; removing the insulation pattern from the cell
area, thereby forming a first contact hole through which the
junction layer under the insulation pattern is exposed; removing a
peripheral portion of the cutting pattern from the power area,
thereby forming a second pattern through which a device isolation
layer under the cutting pattern and a side surface of the flat
portion of the junction layer is exposed and a junction cutting
pattern having a width smaller than that of the cutting pattern
under the first interlayer dielectric pattern; and forming a cell
contact in the first contact hole and a power contact in the second
contact hole such that the cell contact makes contact with the
junction layer in the cell area and the power contact makes contact
with the device isolation layer.
19. The method of claim 17, further comprising, after forming the
gate trench, forming a separation pattern for separating an NMOS
transistor and a PMOS transistor on a separation area between an
NMOS in which the NMOS transistors are arranged area and a PMOS
area in which the PMOS transistors are arranged in the cell
area.
20. The method of clam 19, wherein forming the separation pattern
includes: forming an additional mask pattern on an entire surface
of the substrate having the gate trench such that at least a
portion of the separation area is exposed through the additional
mask pattern; forming a separation opening through which a device
isolation layer surrounding the active fin is exposed by partially
removing a gate spacer defining the gate trench and the insulation
pattern at least partially covering the junction layer between the
neighboring gate spacers, and filling the separation opening with
insulation materials.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 15 U.S.C. .sctn. 119
to Korean Patent Application No. 10-2018-0090472, filed on Aug. 2,
2018 in the Korean Intellectual Property Office, the disclosure of
which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to a semiconductor device,
and more particularly, to a semiconductor device and a method of
manufacturing the same.
DISCUSSION OF THE RELATED ART
[0003] A logic device is a semiconductor device designed to perform
a particular task. A logic device may be designed by combining a
plurality of ready-made standard cells that each perform a limited
number of logic functions.
[0004] Each standard cell is an integrated circuit (IC) module that
may be optimized for specific requirements and functions. Standard
cells may include a basic cell such as a boolean logic function
(e.g. AND, OR, NOR, inverters), a complex cell having a plurality
of basic cells such as an OAI cell (OR/AND/inverter) and an AOI
cell (AND/OR/inverter), and a storage element such as a
master-slave flip flop and a latch. The logic device is made up of
the basic cell, the complex cell, and the storage element that are
optimally selected to perform a specific function.
[0005] Over time, the size of the standard cell has been reduced
and the degree of integration of the standard cell has been
increased. Accordingly, the density of the logic device has been
increased. For example, the fin FET and the buried transistor
structure have been applied to the standard cell for minimizing the
short channel effect and providing various other process
improvements such as to line edge roughness (LER). The LER may
prevent an electric short between, neighboring patterns in spite of
the reduction of the critical dimension (CD).
[0006] For example, some of the circuit lines of the recent
standard cells tend to extend to the power area from the cell area,
so that the integrated circuits are arranged in a portion of the
power area and in the cell area and the density of the circuit
lines are increased within the same size of the standard cell.
[0007] However, since the neighboring cells are electrically
separated by the power area, the reduction of the power area tends
to cause an electric short between the neighboring cells.
Accordingly, standard cells of a reduced size may be more
susceptible to electric short between the neighboring cells
therein.
SUMMARY
[0008] A semiconductor device includes a substrate having a
plurality of cell areas and a plurality of power areas such that
each of the plurality of cell areas are alternately arranged with
each of the plurality of power areas, in a second direction. A
plurality of gate structures extends in the second direction. Each
of the plurality of gate structures is spaced apart from each other
in a first direction that is substantially perpendicular to the
second direction. A plurality of junction layers is arranged at
both sides of each of the plurality of gate structures and is
arranged in the second direction in such a configuration that each
of the plurality of junction layer has a flat portion that is
proximate to the power area. A plurality of cutting patterns is
arranged in the plurality of power areas and the plurality of
cutting patterns extends in the first direction such that each of
the plurality of gate structures and each of the plurality of
junction layers in neighboring cell, areas a the plurality of cell
areas are separated from each other by the cutting pattern.
[0009] A method of manufacturing a semiconductor device includes
forming a plurality of active fins in at least a pair of cell areas
extending in a first direction. The pair of cell areas are
separated from each other by a power area. A plurality of dummy
gate structures and a plurality of gap fill patterns are formed to
a line shape extending in a second direction, substantially
perpendicular to the first direction, such that each of the
plurality of dummy gate structures and each of the plurality of gap
fill patterns covers the plurality of active fins, alternately with
respect to each other in the first direction. A cutting pattern is
formed in the power area in a line shape extending in the first
direction such that the plurality of dummy gate structures and the
plurality of gap fill patterns are separated from each other by a
unit of a cell area of the at least the pair of cell areas. A
junction layer is formed in a gap space between neighboring dummy
gate structures, of the plurality of dummy gate structures, such
that the junction layer makes contact with the plurality of active
fins in the at least the pair of cell areas and has a flat portion
making contact with the cutting pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more complete appreciation of the present disclosure and
many of the attendant aspects thereof will be readily obtained as
the same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0011] FIG. 1 is a plan view illustrating a semiconductor device in
accordance with an exemplary embodiment of the present inventive
concept;
[0012] FIGS. 2A to 2E are cross sectional views cut along lines
A-A', B-B', C-C', D-D' and E-E' of the semiconductor device
depicted in FIG. 1, respectively;
[0013] FIG. 3 is a plan view illustrating a semiconductor device in
accordance with an exemplary embodiment of the present inventive
concept;
[0014] FIGS. 4A to 4F are cross sectional views cut along lines
A-A', B-B', C-C', D-D', E-E' and F-F' of the semiconductor device
depicted in FIG. 3, respectively;
[0015] FIGS. 5 to 32E are views illustrating processing steps of a
method of manufacturing a semiconductor device in accordance with a
exemplary embodiment of the present inventive concept; and
[0016] FIGS. 33 to 40F are views illustrating processing steps of a
method of manufacturing a semiconductor device in accordance with
an exemplary embodiment of the present inventive concept.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Reference will now be made to exemplary embodiments, which
are illustrated in the accompanying drawings, wherein like
reference numerals may refer to like components throughout the
specification and the drawings.
[0018] FIG. 1 is a plan view illustrating a semiconductor device in
accordance with an exemplary embodiment of the present inventive
concept. FIGS. 2A to 2E are cross sectional views cut along lines
A-A', B-B', C-C', D-D' and E-E' of the semiconductor device in FIG.
1, respectively.
[0019] Referring to FIGS. 1 to 2E, a semiconductor device, in
accordance with an exemplary embodiment of the present inventive
concept, may include a substrate 100 having a plurality of cell
areas C and a plurality of power areas PA such that the cell areas
C and the power areas PA may be alternately arranged in a second
direction II. A plurality of gate structures 500 extends in the
second direction II and are spaced, apart from each other in a
first direction I, which is substantially perpendicular to the
second direction II. A plurality of junction layers 300 is arranged
at both sides of the gate structures 500 and is arranged in the
second direction II in such a configuration that each of the
plurality of junction layer 100 may have a flat portion A around
the power area PA. A plurality of cutting patterns CP is arranged
in the power areas PA and these cutting patterns CP extend in the
first direction I such that the gate structures 500 and the
junction layers 300 in neighboring cell areas may be separated from
each other by the cutting pattern CP.
[0020] For example, the substrate 100 may include a bulk substrate,
e.g., a silicon (Si) substrate, a germanium (Ge) substrate, a
silicon germanium (Si-Ge) substrate, a gallium phosphorus (Ga-P)
substrate, a gallium arsenide (Ga-As) substrate, a silicon antimony
(Si-Sb) substrate, The substrate 100 may alternatively include a
multilayered substrate, e.g., a semiconductor on insulator (SOI)
substrate, a germanium on insulator (GOI) substrate.
[0021] The substrate 100 may include a plurality of cell areas C in
which a plurality of cell transistors may be arranged and a power
area PA in which a power rail 700 may be arranged, Hereinafter, the
neighboring cell areas around the power area PA may be referred to
as a first cell area C1 and a second cell area C2, and the first
and the second cell areas C1 and C2 may be separated from each
other by the power area PA.
[0022] According to an exemplary embodiment, each of the cell areas
C may be divided into a PMOS area P and an NMOS area N that may be
separated from each other by a separation area PNS. Thus, a
plurality of PMOS transistors and NMOS transistors may be arranged
in the cell area C and the PMOS transistor and the NMOS transistor
may be separated from each other by the separation area PNS, so
that CMOS transistors may be arranged in the cell areas C.
Hereinafter, the separation area PNS in the first cell area C1 may
be referred to as first separation area PNS1 and the separation
area PNS in the second cell area C2 may be referred to as second
separation area PNS2.
[0023] A plurality of active fins 110 may be arranged in the cell
area C. The active fin 110 may extend in the first direction I and
neighboring active fins 110, of the plurality of active fins 110,
may be spaced apart from each other in the second direction B. The
active fin 110 may protrude from a device isolation layer 120, so
the active fin 110 may be divided into a lower fin 110a that may be
at least partially enclosed with the device isolation layer 120 and
an upper fin 110b that may extend from the device isolation layer
120. For example, a field area of the substrate 100 may be at least
partially covered with the device isolation layer 210 and an active
area of the substrate 100 may be provided as the active fin 110
protruded from the device isolation layer 120.
[0024] A gate structure 500 may be arranged on each active fin 110
and a plurality of the gate structures 500 along the second
direction II may be formed into a gate line GL. A plurality of the
gate lines GL may be spaced apart by the same gap distance in the
first direction I. A side surface of the gate line GL may be at
least partially covered by a gate spacer 240 that may be shaped
into a line in the second direction II.
[0025] For example, the gate line GL may discontinuously extend in
the second direction II by the power area PA. For example, the gate
line GL may extend in the first cell area C1 along the second
direction II and may be broken or otherwise not arranged in the
power area PA. The gate line GL may also extend in the second cell
area C2 along the second direction II.
[0026] Thus, the gate line GL may be arranged exclusively in the
cell area C and the gate line GL in the first cell area C1 may be
symmetrical with the gate line GL in the second cell area C2 with
respect to a gate cutting pattern CP. The gate structure 500 and
the active fin 110 may function as a gate electrode of a cell
transistor in the cell area C.
[0027] The cutting pattern CP may include an insulation material
such as silicon nitride (SiN), so the gate structures 500 in the
first cell area C1 may be electrically separated from die gate
structures 500 in the second cell area C2 by the cutting pattern CR
For example, the gate structures 500 in the first cell area C1 may
be separated from the gate structures 500 in the second cell area
C2 by the power area PA.
[0028] In an exemplary embodiment, the gate structure 500 may
include a gate insulation pattern 510, a work function control
pattern 520 and a gate electrode 530 that may be sequentially
stacked on the active fin 110 and the device isolation layer 120
and may be defined by the gate spacer 240. A gate trench defined by
the work function control pattern 520 may extend in the second
direction II and the gate electrode 530 may fill up the gate
trench. A gate signal may be transferred to the semiconductor
device via the gate structure 500.
[0029] A junction layer 300 may be arranged at both sides of the
gate structure 500. A space between the neighboring gate spacers
240 may be provided as an inter-space trench IST in the cell area
C, and the junction layer 300 may be grown on the active fin 110 in
the inter-space trench IST. For example, when the neighboring
active fins 110 may be closely arranged in the inter-space trench
IST, the junction layers 300 on the neighboring active fins 110 may
be connected with each other just like a line extending in the
second direction II in the cell area C.
[0030] The junction layer 300 may be grown on the active fin 110
around the gate structure 500 by a selective epitaxial growth (SEG)
process, so that an epitaxial pattern may be provided as the
junction layer 120. Thus, when the neighboring active fins 110 may
be closely arranged in the inter-space trench IST, the epitaxial
pattern may be grown in the second direction II and be connected to
each other. Thus, the junction layer 300 may be selectively
connected to each other and may be provided as a discontinuous line
in the cell area C.
[0031] For example, the junction layer 300 in the first cell area
C1 may also be separated from the junction layer 300 in the second
cell area C2 by the power area PA, so that the junction layer 300
in the first cell area C1 and the junction layer 300 in the second
cell area C2 may also be separated from each other by the cutting
pattern CP in the power area PA.
[0032] Therefore, the junction layer 300 in the first cell area C1
and the junction layer 300 in the second cell area C2 do not make
contact with each other in the SEG process due to the cutting
pattern CP in the power area PA. For example, an electrical short
of the junction layer 300 between the first cell area C1 and the
second area C2 may be substantially prevented by the cutting
pattern CP in the power area PA.
[0033] The junction layer 300 around the power area PA may be grown
on the active fin 110 horizontally toward the power area PA as well
as grown vertically, so the junction layer 300 may also be grown
along a side surface of the cutting pattern CP in a third direction
III. For example, the growth of the junction layer 300 in the
second direction H toward the power area PA may be prohibited by
the cutting pattern CP.
[0034] Thus, the junction layer 300 around the power area PA may be
grown along the side surface of the cutting pattern CP in the third
direction III and may have a larger size than the junction layer
300 that is farther from the power area PA. For example, the
junction layer 300 around the power area. PA may have a flat
portion A making contact with the cutting pattern CP and may have a
larger size than that of the junction layer 300 that is farther
from the cutting pattern CP along the same inter-spacer trench
IST.
[0035] The large size of the junction layer 300 may reduce the
contact resistance of the contact structure 600, and the size of
the junction layer 300 may be changed according to the contact
resistance. For example, the process conditions of the SEG may be
controlled in such a way that the size of the flat portion A of the
junction layer 300 may be sufficiently sized to achieve a desired
contact resistance.
[0036] The junction layer 300 that is farther from the cutting
pattern CP may have no growth restrictor such as the cutting
pattern CP, so the junction layer 300 that is farther from the
cutting pattern CP may be grown horizontally as well as grown
vertically without any substantial limitations. Thus, when the
neighboring active fins 110 may be sufficiently separated from each
other in the second direction or the active fin 110 may be arranged
around the separation area PNS, the junction layer 300 may have a
point portion B due to the non-restricted isotropic epitaxial
growth behavior.
[0037] For example, when the neighboring active fins 110 may be
closely arranged in the inter-space trench IST, the neighboring
junction layer 300 may be bonded to each other in the second
direction II due to the horizontal growth of the SEC process.
Accordingly, the junction layer 300 may be shaped into a broken
line extending in the second direction II.
[0038] When the growth restrictor is not be provided in the SEG
process, the junction layer 300 might not be grown vertically and
may instead be formed to have the point portion B. Thus, the
junction layer 300 having the point portion B may have a smaller
size that that of the junction layer having the flat portion A.
Therefore, the closer to the cutting pattern CP the larger the size
of the junction layer 300, and the closer to the separation area
PNS the smaller the size of the junction pattern 300.
[0039] The inter-space trench IST may be filled up with the
conductive contact structure 600 making contact with the junction
layer 300, so that the contact structure 600 may be shaped into a
line extending in the second direction II. Further, the line-shaped
Contact structure 600 might not be positioned in the separation
area PNS, so that the contact structure 600 may be broken in the
separation area PNS and may be discontinuous in the cell line
C.
[0040] The gate structure 500 may be at least partially covered by
a gate capping pattern 550 and a first interlayer dielectric
pattern ILD1 and the junction layer 300 around the gate structure
300 in the inter-space trench IST may be at least partially covered
by the contact structure 600 extending in the second direction II.
For example, an upper surface of the contact structure 600 may be
substantially coplanar with an upper surface of the gate structure
500 or the gate line GL.
[0041] While the gate line GL may be continuous in the cell area C,
the contact structure 600 may be separated into an NMOS contact 612
and a PMOS 614 contact by an insulation pattern 400 filling the
separation area PNS.
[0042] For example, the contact structure 600 may include a cell
contact 610 making contact. with the junction layer 300 in the cell
area C and a power contact 620 making a surface contact with the
flat portion of the junction layer 300 in the power area PA. The
cell contact 610 and the power contact 620 may be provided in one
body. The cell contact 610 may include the NMOS contact and the
PMOS contact and may be provided as a contact plug making contact
with a single junction layer 300 and may be provided as a contact
line making contact with a plurality of the junction layers 300 in
the second direction II.
[0043] The power contact 620 may make surface contact with the flat
portion A of the junction layer 300 and may be positioned in a
peripheral portion of the power area PA in such a configuration
that the power contact 620 may make surface contact with the side
surface of the cutting pattern CP. A peripheral portion of the
cutting pattern CP may be removed from the substrate 100 and a
second contact hole CTH2 may be provided in such a configuration
that the flat portion A of the junction layer 300 and the device
isolation layer 120 may be exposed through the second contact hole
CTH2. The power contact 620 may be positioned in the second contact
hole CTH2 in such a configuration that the power contact 620 may be
in contact with the device isolation layer 120 and an upper surface
of the power contact 620 may be coplanar with an upper surface of
the cutting pattern CP. Since the power contact 620 may make
surface contact with the flat portion A of the junction layer 300,
the contact resistance between the junction layer 300 and the
contact structure 600 may be sufficiently reduced in the
semiconductor device.
[0044] Thus, the cutting pattern CP may include a gate cutting
pattern CP1 cutting the gate line GL in the power area PA and
having a first width w1 and a junction cutting pattern CP2 cutting
the junction layer 300 in the power area PA and having a second
width w2 smaller than the first width w1. The gate cutting pattern
CP1 and the junction cutting pattern CP2 may be alternately
arranged along the first direction I in the power area PA.
[0045] The power contact 620 in the first cell area C1 may be
symmetrical with the power contact 620 in the second cell area C2
with respect to the junction cutting pattern CP2, so that the power
contact 620 in the first cell area C1 may be substantially
prevented from being connected with the power contact 620 in the
second cell area C2 by the junction cutting pattern CP2. For
example, an electrical short of the junction layer 120 between the
first and the second cell areas C1 and C2 may be substantially
prevented by the cutting pattern CP in the power area PA.
[0046] The cell contact 610 may be separated into the NMOS contact
612 and the PMOS contact 614 by the insulation pattern 400 in the
cell area C. Thus, the NMOS contact 612 and the PMOS contact 614
may also be electrically separated from each other by the
insulation pattern 400 in the cell area C.
[0047] The power contact 620 may be connected to a power rail 700
at least partially covering the power area PA. Since the power rail
700 may be in contact with the upper surface of the cutting pattern
CP and the upper surface of the power contact 620 may be coplanar
with the upper surface of the cutting pattern CP. The power rail
700 may also be in contact with the power contact 620 at the
peripheral portion of the power area PA.
[0048] The power rail 700 may include a power plug 710 making
contact with the power contact 620 and extending upwards. The power
rail 700 may additionally include a power line 720 making contact
with the power plug 710 and extending in the first direction I on
the first interlayer dielectric pattern ILD1. In the present
exemplary embodiment, the power plug 710 and the power line 720 may
be provided in one body.
[0049] The power plug 710 may be symmetrically arranged at both
sides of the junction cutting pattern CP2 in such a configuration
that a lower surface of the power plug 710 may be in contact with
the power contact 620 and an upper surface of the power plug 710
may be coplanar with an upper surface of the first interlayer
dielectric pattern ILD1. The power line 720 may extend in the first
direction I in such a configuration that a lower surface of the
power line 720 may be alternately in contact with the power plug
710 and the first interlayer dielectric pattern ILD1 in the power
area PA.
[0050] When a power signal may be applied to the power rail 700
from an external power source, the power signal may be transferred
to the junction layer 300 via the power contact 620. For example,
the power signal may be simultaneously transferred to the junction
layer 300 of the first cell area C1 and the junction layer 300 of
the second cell area C2. Since the power contact 620 in the first
cell area C1 may be insulated from the power contact 620 in the
second cell area C2 by the junction cutting pattern CP2, the power
signal may be individually transferred to the junction layer 300 in
both of the first cell, area C1 and the second cell area C2.
[0051] In addition, since the cell contact 610 may be separated
into the NMOS contact 612 and the PMOS contact 614 by the
insulation pattern 400 in the cell area C, the power signal may be
transferred to one of the NMOS contact 612 and the PMOS contact
614. Thus, the NMOS contact 612 and the PMOS contact 614 in the
same cell area C might not simultaneously receive the power signal
from the same power rail 700. Some of the power rails 700 may
transfer the power signal to the NMOS contact 612 and the rest of
the power rails 700 may transfer the power signal to the PMOS
contact 614.
[0052] In the present, exemplary embodiment, a PMOS area P may be
arranged around the power rail 700 and an NMOS area N may be
arranged apart from the power rail 700 and disposed close to
another power rail. Thus, the power signal may be transferred to
the PMOS contact 614 through the power rail 700 and transferred to
the NMOS contact 612 through another power rail that may be spaced
apart from the power rail 700 in the second direction II.
[0053] A plurality of the power rails 700 may extend in the first
direction I and may be spaced apart from each other in the second
direction II. A second inter layer dielectric pattern ILD2 may be
filled with the gap space between the neighboring power rails 700,
so the neighboring power rails 700 may be insulated from each other
by the second interlayer dielectric pattern ILD2.
[0054] According to the present exemplary embodiment of the
semiconductor device, the gate line GL and the junction layer 300
extending in the second direction II may be cut by the cutting
pattern CP that may be arranged in the power area PA, so the gate
line GL and the junction layer 300 may be separated by a unit of
the cell area C. Thus, the gate line CCL and the junction layer 300
in the first cell area C1 may be substantially prevented from being
connected to the gate line C2 and the junction layer 300 in the
second cell area C2. Accordingly, electric short of the gate line
GL and the junction layer 300 may be substantially prevented
between the first and the second cell areas C1 and C2.
[0055] Further, the power contact 620 making contact with the
junction layer 300 may be arranged at both sides of the junction
cutting, pattern CP2 symmetrically with respect to the junction
cutting pattern CP2. Thus, the power signal may be individually and
independently transferred to the first and second cell areas C1 and
C2. For example, the power signal transferred to the PMOS contact
614 in the first cell area nay be prevented from leaking to the
PMOS contact 614 in the second cell area C2, and the power signal
transferred to the PMOS contact 614 in the second cell area C2 may
be prevented from leaking to the PMOS contact 614 in the first cell
area C1.
[0056] In addition, since the power contact 620 may make surface
contact with the junction layer 300, the contact resistance between
the junction layer 300 and the contact structure 600 may be
sufficiently reduced in the semiconductor device.
[0057] Accordingly, when the power area PA may be reduced according
to the size reduction of the recent semiconductor devices, an
electric short of the gate line GL and the junction layer 300 may
be substantially prevented or minimized between the neighboring
cell areas C that may be separated by the power area PA. For
example, an electric short of the transistors between the
neighboring cell areas C separated by the power area PA may be
substantially prevented by the cutting pattern CA in the power area
PA.
[0058] While the cutting pattern for preventing the neighboring
transistors in different cell areas C may be arranged in the power
area PA, an electric shorts of the neighboring transistors may also
occur in the same cell area C via the separation area PNS. Thus,
the cutting pattern may be further provided in the separation area
PNS as well as the power area PA.
[0059] FIG. 3 is a plan view illustrating, a semiconductor device
in accordance with an exemplary embodiment of the present inventive
concept. FIGS. 4A to 4F are cross sectional views cut along lines
E-E' and F-F' of the semiconductor device in FIG. 3, respectively.
The semiconductor device in FIG. 3 has substantially the same
structures as the semiconductor device shown in FIG. 1, except that
a separation pattern SP may be further arranged in the separation
area PNS in each cell area C. Thus, in FIGS. 3 to 4F, the same
reference numerals in FIGS. 1 to 2E may be used to denote the same
elements and to the extent that further descriptions of various
elements is omitted, it may be assumed that these elements are at
least similar to corresponding elements that have already been
described.
[0060] Referring to FIGS. 3 to 4F, a separation pattern 300 may be
arranged in the separation area PNS in such a way that the gate
line GL and the junction layer 300 in the PMOS area P might not be
connected to the gate line GL and the junction layer 300 in the
NMOS area N.
[0061] Prior to the formation of the gate structure 500, the
insulation pattern 400 may be removed form the substrate 100 and a
separation hole SO in FIG. 33 may be formed in the separation area
PNS. The separation hole may be formed in the whole separation area
PNS or in a portion of the separation area PNS according to a
layout of the semiconductor device.
[0062] In the present exemplary embodiment, the separation hole SO
may extend in the first direction I through the gate spacer 240 and
may include the gate trench and the inter-space trench IST I in the
first direction I. Thus, the separation pattern SP may extend in
the first direction I in the cell area C and at least one gate line
GL and at least one junction layer 300 may be separated by the
separation pattern SP in the cell area C.
[0063] The separation pattern SP may have substantially the same
insulation material as the cutting pattern CP. For example, the
separation pattern SP may include silicon nitride (SiN), silicon
oxynitride (SiON), and/or silicon carbon oxynitride (SiOCN).
[0064] Accordingly, the gate structure 500 in the PMOS area P and
the gate structure 500 in the NMOS area N may be electrically
separated by the separation pattern SP in the cell area C. In the
same way, the junction layer 300 in the PMOS area P and the
junction layer 100 in the NMOS area N may also be electrically
separated by the separation pattern SP in the cell area C. Thus,
the PMOS transistor and the NMOS transistor may be sufficiently
separated from each other by the separation pattern SP in the same
cell area C although the size of the semiconductor device may be
reduced. For example, the semiconductor device may be formed into a
stable and reliable CMOS device.
[0065] FIGS. 5 to 32E are views illustrating processing steps of a
method of manufacturing a semiconductor device in accordance with
an exemplary embodiment of the present inventive concept. In FIGS.
5 to 32E, odd-numbered figures are plan views illustrating each
processing step for the manufacturing method and even-numbered
figures are cross sectional views corresponding to the odd-numbered
figure. Each figure designated by the subscript `A` in the drawing
number is a cross-sectional view cut along a line A-A' of the
semiconductor device shown in FIG. 1, and each figure designated by
the subscript `B` in the drawing number is a cross-sectional view
cut alone a line B-B' of the semiconductor device shown in FIG. 1.
In addition, each figure designated by the subscript `C` in the
drawing number is a cross-sectional view cut along a line C-C' of
the semiconductor device shown in FIG. 1, and each figure
designated by the subscript `D` in the drawing number is a
cross-sectional view cut along a line of the semiconductor device
shown in FIG. 1. Each figure designated by the subscript `E` in the
drawing number is a cross-sectional view cut along a line E-E' of
the semiconductor device shown in FIG. 1.
[0066] Referring to FIGS. 5 and 6A to 6B, an upper portion of the
substrate 100 may be partially removed and a plurality of recesses
R may be formed on the substrate 100 in such a way that a plurality
of active fins 110 may be arranged on the substrate 100. The
neighboring active fins 110 may be spaced apart from each other by
the recess R.
[0067] For example, the substrate 100 may include a bulk substrate,
e.g., a silicon (Si) substrate, a germanium (Ge) substrate, a
silicon germanium (Si-Ge) substrate, a gallium phosphorus (Ga-P)
substrate, a gallium arsenide (Ga-As) substrate, a silicon antimony
(Si-Sb) substrate. Alternatively, the substrate 100 may include a
multilayered substrate, e.g., a semiconductor on insulator (SOI)
substrate, a germanium on insulator (GOI) substrate.
[0068] A mask pattern for defining an active region of the
substrate 100 may be formed on the substrate 100 and a dry etching
process may be conducted to the substrate 100 using the mask
pattern as an etching mask, so that an upper portion of the
substrate 100 may be partially removed to thereby form the recesses
R on the substrate 100. An etched portion of the substrate 100 may
function as a field region F of the substrate 100 and a non-etched
portion of the substrate 100 may protrude upwards from the bottom
of the recess R just like a fin 110 and function as an active
region A of the substrate 100. Thus, the substrate 100 may have the
field region F corresponding to the recess R and the active region
A corresponding to the fin 110. The active region A shaped into the
fin is referred to as active tin 110. In the present exemplary
embodiment, the active fin 110 may be formed into a line extending
in the first direction I.
[0069] The substrate 100 may include a plurality of cell areas C in
which a plurality of cell transistors may be arranged and a power
area PA in which the power rail 700 such as a metal line may be
arranged. The cell area C and the power area PA may be alternately
arranged on the substrate 100 in the second direction II. For
example, the contact structure 600 may be formed in the power area
PA and the power signal may be simultaneously transferred to the
neighboring cell areas close to the power area PA.
[0070] The first cell area C1 may be separated from the second cell
area C2 by the power area PA and may be, symmetrical to each other
with respect to the power area PA. The power area PA may include a
first power area PA1 for holding the contact structure 600 through
which the power signal may be transferred to the first cell area C1
and a second power area PA2 for holding the contact structure 600
through which the power signal may be transferred to the second
cell area C2.
[0071] Each of the cell area C may include the PMOS area P and the
NMOS area N. A PMOS transistor may be formed on the PMOS area P and
the NMOS transistor may be formed on the NMOS area N so that the
CMOS transistor may be formed in each of the cell area C. For
example, since the first and the second cell areas C1 and C2 may be
symmetrical to each other with respect to the power area PA, the
PMOS area P and the NMOS area N of the first cell area C1 may be
folded onto the PMOS area P and the NMOS area N of the second cell
area C2.
[0072] Therefore, a first power signal may be simultaneously
transferred to both of the PMOS transistors in the first and the
second cell, areas C1 and C2 by the power rail 700 in the power
area. PA interposed between the first and the second cell areas C1
and C2. Then, a second power signal may be transferred to both of
the NMOS transistors in the first and the second cell areas C1 and
C2 by another power rail in another power area that may be arranged
at a top portion of the first cell area C1 and at a bottom portion
of the second cell area C2.
[0073] For example, the PMOS area P and the NMOS area N may be
separated from each other by the separation area PNS in each cell
area C. Thus, the NMOS transistor and the PMOS transistor may be
electrically separated from each other by the insulation pattern
400 in the separation area PNS of each cell area C. Thus, when only
PMOS transistor or only NMOS transistor would be formed in the cell
area C, the separation area PNS might not be provided with the cell
area C. Hereinafter, the separation area PNS in the first cell area
C1 is referred to as first separation area PNS1 and the separation
area PNS in the second cell area C2 is referred to as second
separation area PNS2 for convenience's sake.
[0074] The active fin 110 may be formed into a line shape extending
in the first direction in the PMOS area P and the NMOS area N.
While a single active fin 110 may be formed in each of the PMOS
area P and the NMOS area N as shown in FIG. 6A, the single active
fin 110 represents a plurality of the active fins 110 that may be
spaced apart from each other in the second direction II. The
configurations and the structures of the plurality of the active
fins may be varied according to the layout of the semiconductor
device.
[0075] Referring to FIGS. 7 and 8A to 8B, the device isolation
layer 120 may be formed on the substrate 100 in such a way that a
lower portion of the active fin 110 (referred to as lower fin 110a)
may be surrounded on two sides by the device isolation layer 120
and an upper portion of the active fin 110 (referred to as upper
fin 110b) may protrude from the device isolation layer 120.
[0076] For example, an insulation layer may be formed on the
substrate 100 to a sufficient thickness to fill up the recess R and
the insulation layer may be planarized until a top surface of the
active fin 110 may be exposed.
[0077] Then, a mask pattern may be formed on the substrate 110
having the insulation layer in such a way that the active fin 110
may be at least partially covered by the mask pattern. Then, the
insulation pattern may be further removed by an etching process
using the mask pattern as an etch mask until a top, surface of the
insulation layer may be lower than the top surface of the active
fin 110, thereby forming the insulation layer 120 in a lower
portion of the recess R. For example, the device isolation layer
120 may cover the field region F at the lower portion of the recess
R and an upper surface of the device isolation layer 120 may be
lower than the top surface of the active fin 110. For example, the
device isolation layer 120 may include an insulation material such
as silicon oxide (SiO).
[0078] Thus, an entire surface of the substrate 100 may be covered
by the device isolation layer 120, except for the active fin 110.
The lower fin 110a may be at least partially enclosed by the device
isolation layer 120 and the upper fin 110b may be exposed to
surroundings.
[0079] While the present exemplary embodiment discloses that the
device isolation layer 120 may be formed through a deposition
process, a planarization process and an etching process, the device
isolation layer 120 may be formed through other processes. For
example, the device isolation layer 120 may be formed through a
selective epitaxial growth (SEG) process using the bottom of the
recess R as a seed.
[0080] Referring to FIGS. 9 and 10A to 10C, a preliminary dummy
gate structure 200a may be formed on the device isolation layer 120
as a line extending in the second direction II.
[0081] A dummy gate insulation layer may be formed on the device
isolation layer 120 along a surface profile of the upper tin 110b
and a dummy gate electrode layer may be formed on the dummy gate
insulation layer to a sufficient thickness to fill up gap spaces
between the neighboring upper fins 110b.
[0082] For example, the dummy gate insulation layer may include an
oxide such as silicon oxide, and the dummy gate electrode layer may
include polysilicon. A deposition process such as a chemical vapor
deposition (CVD) process and an atomic layer deposition (ALD)
process may be conducted for forming the dummy gate insulation
layer and the dummy gate electrode layer,
[0083] Then, a mask layer may be formed on the dummy gate electrode
layer and may be partially removed from the dummy gate electrode
layer by a photolithography process, thereby forming a line-shaped
mask pattern 230 extending in the second direction II on the dummy
gate electrode layer.
[0084] The dummy gate insulation layer and the dummy gate electrode
layer may be partially removed from the device isolation layer 120
by an etching process using the line-shaped mask pattern 230 as an
etch mask, thereby forming a dummy gate insulation pattern 210 and
a dummy gate electrode pattern 220 into a line pattern extending in
the second direction II. The line-shaped dummy gate electrode
pattern 220 and the dummy gate insulation pattern 210 may be formed
into, a preliminary dummy gate structure 200a extending in the
second direction II. The neighboring preliminary dummy gate
structures 200a may be spaced apart from each other by a gap
distance in the first direction I.
[0085] Referring to FIGS. 11 and 12A to 12C, a gate spacer 240 may
be formed on both sides of the preliminary dummy gate structure
200a and a dummy gate structure 200 defined by the gate spacer 240
may be formed on the device isolation layer 120
[0086] A spacer layer may be formed on the preliminary dummy gate
structure 200a and the device isolation layer 120. Then, the spacer
layer may be partially removed from the device isolation layer 120
by an anisotropic etching process, thereby forming the gate spacer
240 at least partially covering the side surfaces of the dummy gate
insulation pattern 210 and the dummy gate electrode pattern 220.
For example, the gate spacer 240 may include a nitride such as
silicon nitride (SiN) and silicon carbon oxynitride (SiOCN).
[0087] When the anisotropic etching process may be conducted to the
spacer layer, the mask pattern 230 may also be removed from the
dummy gate electrode pattern 220 and thus an upper surface of the
gate spacer 240 may be coplanar with an upper surface of the dummy
gate electrode pattern 220.
[0088] Thus, the preliminary dummy gate structure 200a may be
formed into the line-shaped dummy gate structure 200 having the
dummy gate insulation pattern 210 and the dummy gate electrode
pattern 220 and extending in the second direction II and both sides
of the dummy gate structure 200 may be at least partially covered
by the gate spacer 240. The gate spacer 240 may be shaped into a
line extending in the second direction II and the device isolation
layer 120 and the active fin 110 may be alternately exposed in the
second direction II through a gap space between the neighboring
gate spacers 240. Hereinafter, the gap space between the
neighboring gate spacers 240 is referred to as the inter-space
trench IST, so the inter-space trench IST may extend in the second
direction II.
[0089] Referring to FIGS. 13 and 14A to 14C, a gap-fill pattern 250
may be formed in the inter-space trench IST in such a way that the
device isolation layer 120 and the active fin 110 may be at least
partially covered by the gap-fill pattern 250.
[0090] For example, a gap-fill layer may be formed on a whole
surface of the substrate 100 having the dummy gate structure 200
and the gate spacer 240 to a sufficient thickness for filling up
the inter-space trench IST. Thus, the dummy gate structure 200 and
the gate spacer 240 may be at least partially covered by the
gap-fill layer. The gap-fill layer may include an oxide such as
silicon oxide (SiO) and may be formed by a deposition process such
as the CND process and the ALD process.
[0091] Then, the gap-fill layer may be planarized by a
planarization process such as a chemical mechanical polishing (CMP)
process and an etch-back process until the upper surface of the
dummy Rate structure 200 may be exposed, and thus the gap-fill
layer may remain exclusively in the inter-spacer trench IST as the
gap-fill pattern 250. The gap fill pattern 250 may be shaped into a
line extending in the second direction II and an upper surface of
the gap fill pattern 250 may be substantially coplanar with the
upper surface of the dummy gate electrode pattern 220.
[0092] Referring to FIGS. 13 and 16A to 16D, the dummy gate
structure 200, the gate spacer 240 and the gap fill pattern 250 may
be removed from the device isolation layer 120, thereby forming a
cutting trench CT through which the device isolation layer 120 may
be exposed in the power area PA along the first direction I.
[0093] For example, a power cutting mask may be formed on the gap
fill pattern 250 and the dummy gate structure 200 in such a way
that the cell area C may be at least partially covered by the power
cutting mask and the power area PA may be exposed through the power
cutting mask. Then, the dummy gate structure 200, the gate spacer
240 and the gap fill pattern 250 may partially be removed from the
device isolation layer 120 in the power area PA by aft etching
process using the power cutting mask as an etch mask.
[0094] In the present exemplary embodiment, the gap till pattern
250 may include silicon oxide and the gate spacer 240 may include
silicon nitride and the dummy gate structure 200 may include
silicon oxide and polysilicon. Thus, the process conditions of the
etching process may be controlled in view of the oxide, the nitride
and the polysilicon. The dummy gate structure 200, the gate spacer
240 and the gap fill pattern 250 may be removed by the etching
process. For example, the dummy gate structure 200, the gate spacer
240 and the gap fill pattern 250 may be removed along the power
area PA and the device isolation layer 120 may be exposed along the
power area PA through a trench defined by the dummy gate structure
200, the gate spacer 240 and the gap fill pattern 250 in the cell
area C in the first direction I. Thus, the cutting trench CT may be
formed on the substrate 100 in the power area PA along the first
direction I.
[0095] The cell area C may be separated into the first cell area C1
and the second cell area C2 by the cutting trench CT.
[0096] While the present exemplary embodiment discloses, that the
cutting trench CT may be formed in the whole power area PA, the
cutting trench CT may be formed in a portion of the power area
PA.
[0097] In such a case, the dummy gate structure 200, the gate
spacer 240 and the gap fill pattern 250 may remain in a peripheral
portion of the power area PA and the cutting trench CT may be
formed exclusively in a central portion of the power area PA.
[0098] Referring to FIGS. 17 and 18A to 18D, the cutting pattern CP
may be formed in the cutting trench CT.
[0099] For example, a cutting layer may be formed on the dummy gate
structure 200, the gate spacer 240 and the gap fill pattern 250 to
a sufficient thickness for filling up the cutting trench CT and
then may be planarized until top surfaces of the dummy gate
structure 200, the gate spacer 240 and the gap fill pattern 250 may
be exposed. Therefore, the cutting layer may remain exclusively in
the cutting trench CT thereby forming the cutting pattern CP in the
cutting trench CT.
[0100] The cutting layer may include a nitride such as silicon
nitride (SiN), silicon oxynitride (SiON) and silicon carbon
oxynitride (SiOCN). Thus, the cutting layer may have a sufficient
etch selectivity with respect to the gap fill pattern 250
comprising an oxide and the dummy gate electrode pattern 220
comprising polysilicon.
[0101] The cutting layer may be planarized by one of the CMP
process and the etch-back process until the top surfaces of the
dummy gate structure 200, the gate spacer 240 and the gap fill
pattern 250 may be exposed.
[0102] Accordingly, the cutting pattern CP may be exposed in the
power area PA and, the dummy gate electrode pattern 220, the gate
spacer 240 and the gap fill pattern 250 may be exposed in the first
and the second cell areas C1 and C2. The dummy gate structure 200,
the gate spacer 240 and, the gap fill pattern 250 may be broken by
the cutting pattern CP and may be separated by a unit of the cell
area C.
[0103] Referring to FIGS. 19 and 20A to 20D, the gap fill pattern
250 may be removed from the substrate 100 in the cell area C and
the active fin 110 and the device isolation layer 120 may be
exposed through an inter-spacer hole ISH.
[0104] For example, the gap fill pattern 250 may be removed from
the substrate 100 by an etching process using the dummy gate
electrode pattern 220, the gate spacer 240 as an etch mask. Since
the dummy gate electrode pattern 220 may include polysilicon and
the gate spacer 240 may include silicon nitride while the gap fill
pattern 250 may include silicon oxide, the etching process may be
conducted in such a way that the etch rate of the silicon oxide may
be sufficiently higher than those of the polysilicon and the
silicon nitride.
[0105] Therefore, the inter-spacer trench IST may be formed into
the inter-spacer hole ISH that may be defined by the gate spacer
240 in the cell area C and the cutting pattern CP in the power area
PA. The active fin 110 and the device isolation layer 120 may be
exposed through the inter-spacer hole ISH.
[0106] For example, the active fin 110 in the inter-spacer hole ISH
may be further etched away in the etching process for removing the
gap fill pattern 250, so that an upper portion of the upper fin
110b may be removed to thereby form an active recess AR. Thus, the
upper fin 110b of the inter-spacer hole ISH may have a height that
is smaller than that of the upper fin 110b of the dummy gate
structure 200.
[0107] Referring to FIGS. 21 and 22A to 22D, the junction layer 300
may be formed on the active fin 110 and the device isolation layer
120 in the inter-spacer hole ISH.
[0108] For example, a selective epitaxial growth (SEG) process may
be conducted in the inter-spacer hole ISH by using the upper fin
110b as a seed, thereby forming epitaxial layer in the inter-spacer
hole ISH as the junction layer 300.
[0109] In an exemplary embodiment, a silicon source gas such as a
disilane (Si.sub.2H.sub.6) gas and a carbon source gas such as a
SiH3CH3 gas may be provided for the SEG process and a single
crystalline silicon carbide (SiC) layer may be formed on the active
fin 110 and the device isolation layer 120 as the junction layer
300. Otherwise, the silicon source gas may be provided exclusively
for the SEG process, and a single crystalline silicon (Si) layer
may be formed on the active fin 110 and the device isolation layer
120 as the junction layer 300.
[0110] In such a case, an n-type impurity source gas such as a
phosphine (PH3) gas may be provided in the SEG process together
with the silicon source gas and/or the carbon source gas, and the
single crystalline silicon carbide (SiC) layer and the single
crystalline silicon (Si) layer ay be doped with the n-type
impurities. Therefore, the junction layer 300 doped with the n-type
impurities may function as source/drain electrodes for the NMOS
transistor in the NMOS area N.
[0111] In an exemplary embodiment, a silicon source gas such as a
dichlorosilane H.sub.2SiCl.sub.2) gas and a germanium source gas
such as a germanium tetrahydride (GeH.sub.4) gas may be provided
for the SEG process and a single crystalline silicon germanium
(SiGe) layer may be formed on the active fin 110 and the device
isolation layer 120 as the junction layer 300.
[0112] In such a case, a p-type impurity source gas such as a
diborane (B.sub.2H.sub.6) gas may be provided in the SEG process
together with the silicon source gas and the germanium source gas,
and the single crystalline silicon germanium (SiGe) layer may be
doped with the p-type impurities. Therefore, the junction layer 300
doped with the p-type impurities may function as source/drain
electrodes for the PMOS transistor in the PMOS area P.
[0113] The junction layer 300 may be grown in an isotropic behavior
along horizontally and vertically, so that the junction layer 300
may substantially fill up the active recess AR as well as growing
in the second direction II in the inter-spacer hole ISH. For
example, the cross sectional surface of the junction layer 300 may
be formed into a pentagonal/hexagonal shape.
[0114] When the neighboring active fins 110 may be sufficiently
adjacent to each other in the PMOS area P and the NMOS area N, the
neighboring junction layer 300 on the neighboring active fins 110
may be connected to each other in the second direction II. Thus,
the junction layer 300 may be formed into broken line pieces in the
PMOS area P and the NMOS area N.
[0115] As described above, the single active fin 110 in the PMOS
area P and the NMOS area N represents a plurality of the active
fins 110 that may be spaced apart from each other in the second
direction II. Therefore, the junction layer 300 may be sparsely
arranged on the active fin or may be arranged in a line across a
plurality of the active fins 110 in the second direction II.
[0116] The junction layer 300 may be grown horizontally into the
separation area PNS from the peripheral portion of the NMOS area N
and the PMOS areas P in the second direction II. For example, the
junction layer 300 in the first cell area C1 may be grown
horizontally into the first separation area PNS1 and the junction
layer 300 in the second cell area C2 may be grown horizontally into
the second separation area PNS2 in the second direction II.
[0117] For example, when the junction layer 300 may be grown in the
second direction II around the power area PA, the horizontal growth
may be restricted by the cutting pattern CP and may be forced to
transform into the vertical growth along the side surface of the
cutting pattern CP in the third direction III.
[0118] Thus, the junction layer 300 around the power area PA, may
be grown vertically to a greater extent than the junction layer 300
that is farther from the power area PA, and as result, the size of
the junction layer 309 may be greater around the power area PA than
around the power area PA. In addition, the junction layer 300 may
have the flat portion A making surface contact with the cutting
pattern CP.
[0119] For example, since the epitaxial growth may occur in the
isotropic behavior, the junction layer 300 may be slanted upwards
from the active fin 110 to the cutting pattern CP and an air gap AG
may be generated between the cutting pattern CP and the junction
layer 300 adjacent to the cutting pattern CP. The air gap may also
be generated between the neighboring junction layers 300 in the
PMOS area P and the NMOS area N due to the isotropic behavior of
the SEG process.
[0120] The size of the flat portion A may be varied according to
the process conditions of the SEG process. As described
hereinafter, since the flat portion A may make contact with the
power contact 620, the contact resistance between the junction
layer 300 and the contact structure 600 ay be reduced as the size
of the flat portion A may increase.
[0121] When the vertical epitaxial growth of the junction layer 300
may be non-uniform or unstable along the side surface of the
cutting pattern CP, the flat portion A of the junction layer 300
may be formed non-uniformly along the side surface of the cutting
pattern CP. For example, when the vertical epitaxial growth may be
insufficiently conducted on the side surface of the cutting pattern
CP, the flat portion A may make point contact with the cutting
pattern CP. In such a case, the flat portion A may be composed of
all the contact points between the junction layer 300 and the
cutting pattern CP.
[0122] Since the junction layer 300 that is farther from the
cutting pattern CP may have no growth restrictor such as the
cutting pattern CP in the second direction II, the junction layer
300 that is farther from the cutting pattern CP may be grown
horizontally as well as grown vertically without any substantial
limitations. Thus, the connecting portion between the neighboring
junction layers 300 may have a smaller size than the fiat portion A
between the junction layer 300 and the cutting pattern CP. For
example, when the neighboring active fins 110 may be sufficiently
spaced apart front each other in the second direction or the active
fin 110 may be arranged around the separation area PNS, the
junction layer 300 may have a point portion B due to the
non-restricted isotropic epitaxial growth behavior.
[0123] In addition, since the junction layer 300 around the cutting
pattern CP may be connected to the power rail 700 via the power
contact 620, which will be described in detail hereinafter, the
size increase of the junction layer 300 around the cutting pattern
CP may increase the process margin for forming the power contact
620.
[0124] When the conventional semiconductor devices are reduced in
size according to the recent device trends, the power area PA may
also be reduced in size, and as a result, the junction layers
separated from each other by the power area PA may be
interconnected to each other across the power area PA. However,
according to an exemplary embodiment of the present invention, the
junction layers 300 in the first and the second cell areas C1 and
C2 may be sufficiently separated from each other by the cutting
pattern CP in the power area PA although the size of the power area
PA may be reduced in size. Accordingly, an electric short of the
junction layer 300 between the first and the second cell areas C1
and C2 may be substantially prevented in the semiconductor device,
thereby increasing the yield of the semiconductor device.
[0125] Referring to FIGS. 23 and 24A to 24D, the dummy gate
structure 200 may be removed from the substrate 100, thereby
forming a gate trench extending in the second direction II and
defined by the gate spacer 240.
[0126] An insulation layer may be formed on the substrate 100
having the junction layer 300 to a sufficient thickness for filling
up the inter-spacer hole ISH. Thus, the gate spacer 240 and the
dummy gate structure 200 may be at least partially covered with the
insulation layer. For example, the insulation layer may include an
oxide such as silicon oxide (SiO).
[0127] Then, the insulation layer may be planarized by the CMP
process or the etch-back process until the upper surfaces of the
dummy gate electrode pattern 220 and the gate spacer 240. Thus, the
insulation layer may exclusively remain in the inter-spacer hole
ISH and may be formed into the insulation pattern 400. Thus, the
junction layer 300 may be at least partially covered with the
insulation pattern 400.
[0128] Due to the planarization process, an upper surface of the
insulation pattern 400 may be coplanar with the upper surface of
the dummy gate electrode pattern 220 and the gate spacer 240.
[0129] Thereafter, the dummy ate structure 200 may be removed from
the substrate 100 and the device isolation layer 120 and the active
tin 110 may be exposed through an opening defined by the gate
spacer 240 and the cutting pattern CP, thereby forming the gate
trench extending in the second direction II in the cell area C.
[0130] For example, since the dummy gate electrode pattern 220 may
include polysilicon and the dummy gate insulation pattern 210 may
include silicon oxide, a dry etching process or a wet etching
process may be conducted for removing the dummy gate electrode
pattern 220 and the dummy gate insulation pattern 210 by using the
gate spacer 240 and the cutting pattern CP as an etch mask. In the
etching process for removing the dummy gate electrode pattern 220
and the dummy gate insulation pattern 210, damage to the junction
layer 300 may be prevented from occurring due to the insulation
pattern 400.
[0131] The gate trench may be defined by the gate spacer 240 in the
first direction I and by the cutting pattern CP in the second
direction II. The device isolation layer 120 and the active fin 110
may be exposed through the gate trench.
[0132] Referring to FIGS. 25 and 26A to 26D the gate structure 500
may be formed in the gate trench.
[0133] For example, a gate insulation layer and a work function
control layer may be sequentially formed on the substrate 100 along
a surface profile of the gate trench and a gate electrode layer may
be formed on the work function control layer in such a way that the
gate trench may be sufficiently filled with the gate electrode
layer. In a modified exemplary embodiment, an interface layer may
be further formed between the active fin 110 and the gate
insulation layer.
[0134] The gate insulation layer may include a high dielectric
metal oxide such as hafnium oxide (HfO.sub.2), tantalum oxide
(Ta.sub.2O.sub.5), zirconium oxide (ZrO.sub.2). The work function
control layer may include a metal nitride such as titanium nitride
(TiN), titanium aluminum nitride (TiAlN), tantalum nitride (TaN),
tantalum aluminum nitride (TaAlN) or a metal alloy such as titanium
aluminide (TiAL). Further, the gate electrode layer may include a
lower resistive metal and a nitride of the lower resistive metal.
Examples of the low resistive metal may include aluminum (Al),
copper (Cu), tantalum (Ta), titanium, (Ti), and other metals having
similar electrical resistances. These may be used alone or in
combinations thereof. The work function control layer and the gate
electrode layer may be formed by one of the chemical vapor
deposition (CVD) process, the atomic layer deposition (ALD) process
and a physical vapor deposition (PVD) process. Thereafter, a heat
treatment such as a rapid thermal annealing (RTA), a spike RTA, a
flash RTA and a laser annealing may be further conducted to the
gate electrode layer.
[0135] Then, the gate electrode layer, the work function control
layer and the gate, insulation layer may be planarized until the
upper surfaces of the insulation pattern 400 and the cutting
pattern CP may be exposed, thereby forming a gate insulation
pattern 510, a work function control pattern 520 and a gate
electrode 530 that may be sequentially formed on the active fin 110
and the device isolation layer 120 and may fill up the gate trench
as the gate structure 500. The gate electrode 530 may be at least
partially enclosed by the work function control pattern 520 in the
gate trench. The gate structure 500 may be arranged in the gate
trench and may be formed into the gate line GL extending in the
second direction II in the cell area C.
[0136] The gate structure 500 and the junction layer 300 in the
PMOS area P may constitute the PMOS transistor and the gate
structure 500 and the junction layer 300 in the NMOS area N may
constitute the NMOS transistor. In the present exemplary
embodiment, the gate structure 500 may protrude from the device
isolation layer 120 for enlarging the channel area of transistor,
and thus the PMPS transistor and the NMOS transistor may be
provided as finFET devices.
[0137] The gate structures 500 in the first and the second cell
areas C1 and C2 may be separated from each other in the second
direction II by the cutting pattern CP in the power area PA. As
described above, the junction layer 300 in the first and the second
cell areas C1 and C2 may also be separated from each other in the
second direction II by the cutting pattern CP in the power area
PA.
[0138] Therefore, an electric short of the gate structures 500
between the first and the second cell areas C1 and C2 may be
substantially prevented by the cutting pattern CP and an electric
short of the junction layers 300 between the first and the second
cell areas C1 and C2 may also be substantially prevented by the
same cutting pattern CP.
[0139] Referring to FIGS. 27 and 28A to 28E, a first contact hole
CTH1 may be formed in the cell area C and a second contact hole
CTH2 may be formed in the power area PA. The junction layer 300 in
the PMOS area P and the NMOS area N may be exposed through the
first contact hole CTH1 and the device isolation layer 200 may be
exposed through the second contact hole CTH2.
[0140] A gate capping layer and a first interlayer dielectric layer
may be sequentially formed on the insulation pattern 400, the gate
structure 500 and the cutting pattern CP. Then, the gate capping
layer and the first interlayer dielectric layer may be patterned
into the gate capping pattern 550 and the first interlayer
dielectric pattern ILD1 through which the insulation pattern 400
and the cutting pattern CP may be exposed. For example, the gate
structure 500 and the gate spacer 240 may be at least partially
covered by the gate capping pattern 550 and the gate capping
pattern 500 may be at least partially covered with the first
interlayer dielectric pattern ILD1.
[0141] in the present exemplary embodiment, the gate insulation
pattern 510 may include a nitride such as silicon nitride (SiN) and
the first interlayer dielectric pattern ILD1 may include
substantially the same materials as the insulation pattern 400.
However, the first interlayer dielectric pattern ILD1 may include
insulation materials different from the insulation pattern 400.
[0142] Thereafter, a peripheral portion of the cutting pattern CP
may be removed from a peripheral portion of the power area PA,
thereby forming the second contact hole CTH2 through which the
device isolation layer 120 may be exposed in the power area PA.
Thus, the cutting pattern CP may be formed into the junction
cutting pattern CP2 having a reduced width as much as the size of
the second contact hole CTH2. The junction cutting pattern CP2 may
be arranged at a central portion of the power area PA close to the
insulation pattern 400. In contrast, the cutting pattern CP close
to the gate structure 500 might not be removed from the power area
PA, and thus the width of cutting pattern CP may be unchanged. The
unreduced cutting pattern CP close to the gate structure 500 may be
referred to as the gate cutting pattern CPI as compared with the
junction cutting pattern CP2.
[0143] Thereafter, the insulation pattern 400 may be partially
removed from the NMOS area N and the PMOS area P, thereby forming
the first contact hole CTH1 through which the junction layer 300
may be exposed. Thus, the contact hole CTH1 may include a PMOS
contact hole PCTH through which the junction layer 300 in the PMOS
area P may be exposed and a NMOS contact hole NCTH through which
the junction layer 300 in the NMOS area N may be exposed.
[0144] For example, the insulation pattern 400 might not be removed
from the separation area PNS of the cell area C. For example, the
insulation pattern 400 at least partially covering the separation
area PNS may remain on the device isolation layer 120 of the
separation area PNS. Therefore, the PMOS contact hole PCTH and the
NMOS contact hole NCTH may be separated from each other by the
insulation pattern 400 in the separation area PNS.
[0145] In addition, since the junction cutting pattern CP2 may
remain in the central portion of the power area PA. the second
contact hole CTH2 may be arranged at both sides of the junction
cutting pattern CP2. For example, the second contact hole CTH2 in
the first cell area C1 may be symmetrical to the second contact
hole CTH2 in the second cell area C2 with respect to the junction
cutting pattern CP2.
[0146] In a modified exemplary embodiment, a metal silicide layer
may be further formed on the junction layer 300 exposed through the
first contact hole CTH1.
[0147] Referring to FIGS. 29 and 30A to 30E, the first and the
second contact holes CTH1 and CTH2 may be filled with conductive
materials, thereby forming the contact structure 600 in the first
and the second contact holes CTH1 and CTH2.
[0148] For example, a barrier layer may be formed an the insulation
pattern 400, the first interlayer dielectric pattern ILD1 and
bottom and side walls of the first and the second contact holes
CTH1 and CTH2 along a surface profile of the first and the second
contact holes CTH1 and CTH2. A conductive layer may be formed on
the harrier layer to a sufficient thickness for filling up the
first and the second contact holes CTH1 and CTH2.
[0149] The barrier layer may include a metal such as tantalum and
titanium and a nitride thereof, and the conductive layer may
include a low resistive metal such as tungsten (W), copper (Cu),
and/or aluminum (Al).
[0150] The conductive layer and the barrier layer may be planarized
until an upper surface of the first interlayer dielectric pattern
ILD1 may be exposed, thereby forming a conductive line filling up,
the first and the second contact holes CTH1 and CTH2 and extending
in the second direction II. Thus, the conductive line may pass the
cell area C and the power area PA alternately with each other in
the second direction II. Thereafter, the conductive line may be
further planarized until upper surfaces of the insulation pattern
400 and the junction cutting pattern CP2 may be exposed, thereby
forming the contact structure 600 in the PMOS area P and the NMOS
area N in such a configuration that an upper surface of the contact
structure 600 may be coplanar with the upper surfaces of the upper
surfaces of the insulation pattern 400 and the junction cutting
pattern CP2.
[0151] The contact structure 600 may include the cell contact 610
making contact with the junction layer 300 in the PMOS area P and
the NMOS area N and the power contact 620 making contact with the
device isolation layer 120 in the power area PA and connected to
the cell contact 610 in one body.
[0152] The cell contact 610 may be connected to the junction layer
300 in the NMOS area N and the PMOS area P and the power contact
620 may extend to the power area PA from the cell contact 610. For
example, a pair of the power contacts 620 may be formed at both
sides of the junction cutting pattern CP2 symmetrically with
respect to the junction cutting pattern CP2. Thus, the power
contact 620 in the first cell area C1 may be separated from the
power contact 520 in the second cell area C2, and the junction 300
in the first cell area C1 might not be connected to the power
contact 620 in the second cell area C2 although the power area PA
may be reduced in size.
[0153] As described hereinafter, the power contact 620 may make
contact with the power rail 700 from which the power signal may be
transferred to the MAIDS transistors and the PMOS transistors.
[0154] Thus, the junction 300 in the first cell area C1 may be
sufficiently separated from the power contact 620 in the second
cell area C2 by the junction cutting pattern CP2 and a pair of the
power contacts 620 may be arranged in the power area PA in such a
configuration that the power contact in the first cell area C1 and
the power contact in the second cell area C2 may be simultaneously
in contact with the power rail 700. Thus, the power signal may be
simultaneously transferred to the first cell area C1 and the second
cell area C2 via a pair of the power contacts 620. For example, the
transistors in the first cell area C1 and the second cell area C2
may be simultaneously operated through the single power rail
700.
[0155] Referring to FIGS. 31 and 32A to 32E, a second interlayer
dielectric pattern ILD2 may be formed on the contact structure 600
and the first interlayer dielectric pattern ILD1 and the power rail
700 may be formed on the first interlayer dielectric pattern ILD1
and may make contact with the power contact 620 and the junction
cutting pattern CP2.
[0156] For example, a second interlayer dielectric layer may be
formed on the contact structure 600 and the first interlayer
dielectric pattern ILD1 and may be partially removed from the power
area PA in such, a way that the first interlayer dielectric pattern
ILD1, the power contact 620 and the junction cutting pattern CP2
may be exposed, thereby forming a second interlayer dielectric
pattern ILD2 having a power trench through which the power contact
620 and the junction cutting pattern CP2 may be exposed.
[0157] In the present exemplary embodiment, the second interlayer
dielectric pattern ILD2 may include silicon oxide. In a modified
exemplary embodiment, the second interlayer dielectric pattern ILD2
may include a low dielectric material such as silicon oxide doped
with carbon (C), silicon oxide doped with fluorine (F), porous
silicon oxide, an organic polymer and an inorganic polymer such as
HSSQ and MSSQ.
[0158] Then, a power conductive layer may be formed on the second
interlayer dielectric pattern ILD2 to a sufficient thickness for
filling up the power trench and may be planarized until upper
surface of the second interlayer dielectric pattern ILD2 may be
exposed, thereby forming the power rail 700.
[0159] Thus, the power rail 700 may include a power line 720
extending in the first direction I and arranged on the first
interlayer dielectric pattern ILD1 and a power plug 710 extending
downwards from the power line 720 and making contact with the power
contact 620 and the junction cutting pattern CP2.
[0160] The power plug 710 may be shaped into a vertical rod and an
upper surface of the power plug 710 may have the same level as an
upper surface of the first interlayer dielectric pattern ILD1. The
power line 720 may be arranged on the first interlayer dielectric
pattern ILD1 and the power plug 710 in the first direction I. An
external power signal may be applied to the power line 720 and may
be transferred to the NMOS and PMOS transistors in the cell area C
via the power plug 710 and the power contact 620. For example, the
transistors in both of the first cell area C1 and the second cell
area C2 may be simultaneously operated by a pair of the power
contacts 620.
[0161] A plurality of additional interlayer dielectric patterns may
be further formed on the second interlayer dielectric pattern ILD2
and the power rail 700 and additional contact structures and
wirings may be further formed on the additional interlayer
dielectric patterns so as to connect to the transistors in the cell
area C.
[0162] According to the method of manufacturing the semiconductor
devices, the cutting pattern CP may be formed in the power area PA
and thus the horizontal growth of the junction layer 300 may be
restricted by the cutting pattern CP. Accordingly, the junction
layer 300 in the first cell area C1 may be substantially prevented
from being connected with the junction layer 300 in the second cell
area C2 although the power area PA may be reduced in size, thereby
preventing an electric short of the junction layer 300 between the
first and the second cell areas C1 and C2.
[0163] In addition, the gate structure 500 in the first cell area
C1 may also be sufficiently separated from the gate structure 500
in the second cell area C2 by the cutting pattern CP, so that the
gate structure 500 in the first cell area C1 may be substantially
prevented from being connected with the gate structure 500 in the
second cell area C2 although the power area PA may be reduced in
size, thereby preventing an electric short of the gate structure
500 between the first and the second cell areas C1 and C2.
[0164] Further, a pair of the power contacts 620 may be formed at
both sides of the junction cutting pattern CP2, symmetrically with
respect to the junction cutting pattern CP2, and thus the power
contact 620 in the first cell area C1 may be sufficiently separated
from the power contact 620 in the second cell area C2. Therefore,
the power contact 620 in the first cell area C1 might not be
connected to the power contact 620 in the second cell area C2 due
to the junction cutting pattern CP, thereby preventing electric
short of the power contacts 620.
[0165] Although the power area PA may be reduced in size in
accordance with the size reduction, of the recent semiconductor
devices, the gate structure 500 and the junction layer 300 in
different cell area may be sufficiently separated by a unit of the
cell area. Thus, air electric short of the gate structure 500 and
the junction layer 300 may be substantially prevented in spite of
the size reduction of the power area PA.
[0166] While the present exemplary embodiment discloses the cutting
pattern CP for sufficiently separating the gate structure 500 and
the junction layer 300 by the cell area in spite of the size
reduction of the power area PA, an electric short of the gate
structure 500 and the junction layer 300 may also occur in the
separation area PNS in the cell area C. Thus, the separation of the
gate structure 500 and the junction layer 300 may also be used
between the CMOS area N and the PMSO area P.
[0167] FIGS. 33 to 40F are views illustrating processing steps of a
method of manufacturing a semiconductor device in accordance with
an exemplary embodiment of the present inventive concept. In FIGS.
33 to 40F, odd-numbered figures are plan views illustrating each
processing step for the manufacturing method and even-numbered
figures are cross sectional views corresponding to the odd-numbered
figure. Each figure designated by the subscript `A` in the drawing
number is a cross-sectional view cut along a line A-A' of the
semiconductor device shown in FIG. 3, and each figure designated by
the subscript `B` in the drawing number is a cross-sectional view
cut along a line B-B' of the semiconductor device shown in FIG. 3.
In addition, each figure designated by the subscript `C` in the
drawing number is a cross-sectional view cut along a line C-C' of
the semiconductor device shown in FIG. 3, and each figure
designated by the subscript `D` in the drawing number is a
cross-sectional view cut along a fine D-D' of the semiconductor
device shown in FIG. 3. Each figure designated by the subscript `E`
in the drawing number is a cross-sectional view cut along a line
E-E' of the semiconductor device shown in FIG. 3, and each figure
designated by the subscript `F` in the drawing number is a
cross-sectional view cut along a line F-F' of the semiconductor
device shown in FIG. 3.
[0168] Referring to FIGS. 33 and 34A to 34D, the gate trench may be
formed on the substrate 100 by the same processes as described in
detail with references to FIGS. 5 to 24D and then a separating
opening SO may be formed in the separation area PNS.
[0169] For example, an additional mask pattern AMP may be formed on
a whole surface of the substrate 100 having the gate trench in such
a way that the PMOS area P, the NMOS area N and the power area PA
may be at least partially covered with the additional mask pattern
AMP and the separation area PNS may be partially or wholly exposed
through the additional mask pattern AMP. In such a case, the gate
trench may be filled with the additional mask pattern AMP.
[0170] Then, the gate spacer 240 and the insulation pattern 400 may
be partially or wholly removed from the substrate 100 by a dry
etching process using the additional mask pattern AMP as an etch
mask, thereby forming the separating opening SO through which the
device isolation layer 120 may be exposed.
[0171] For example, the separating opening SO may be disposed
across the gate trench and the junction layer 300 in the first
direction I. The junction layer 300 in the PMOS area P may extend
in the separation area PNS and the junction layer 300 in the NMOS
area N may extend in the separation area PNS, and the separating
opening SO may be formed in the gap space between a pair of the
junction layers 300.
[0172] When the size of the cell area C may be reduced, the gate
structures 500 of the PMOS area P and the NMOS area N may be
connected'to each other in the separation area PNS and the junction
layers 300 of the PMOS area P and the NMOS area N may be connected
to each other in the separation area PNS. Thus, when the cell area
C may be reduced in size, an electric short of the gate structure
500 and the junction layer 300 may occur in the separation area
PNS.
[0173] However, according to exemplary embodiments of the present
invention, a separation pattern SP may be provided in the
separation area PNS for sufficiently separating the gate structure
500 and the junction layer 300 in the PMOS area P from the gate
structure 500 and the junction layer 300 in the NMOS area N,
thereby preventing an electric short between the gate structures
500 and the junction layers 300 in different cell area C.
[0174] Referring to FIGS. 35 and 36A to 36D, a separating pattern
SP may be formed in the separating opening SO for separating the
PMOS area P and the NMOS area N in the cell area C.
[0175] For example, an additional gap fill layer may be formed on
the additional mask pattern AMP to a sufficient thickness for
filling the separating opening SO, and then the additional gap fill
layer may be planarized until upper surfaces of the insulation
pattern 400 and the cutting pattern CP may be exposed. Thus, the
additional gap fill layer may remain exclusively in the separating
opening SO, thereby forming the separating pattern SP in the
separating opening SO and the PMOS area P and the NMOS area N may
be sufficiently separated from each other by the separating pattern
SP.
[0176] The separating pattern SP may include the same materials as
the cutting pattern CP. Thus, the separating pattern SP may include
silicon nitride (SiN), silicon oxynitride (SiON), and/or silicon
carbon oxynitride (SiOCN).
[0177] Thereafter, the additional mask pattern AMP may be removed
from the substrate 100 and the gate trench may be exposed
again.
[0178] Referring to FIGS. 37 and 38A to 38D, the gate structure 500
may be formed in the gate trench.
[0179] For example, a gate insulation layer and a work function
control layer may be sequentially formed on the substrate 100 along
a surface profile of the gate trench and a gate electrode layer may
be thrilled on the work function control layer in such a way that
the gate trench may be sufficiently filled with the gate electrode
layer. Thus, the active fin 110, the device isolation layer 120,
the gate spacer 240, the insulation pattern 400, the cutting
pattern CP and the separating pattern SF may be at least partially
covered by the gate insulation layer, work function control layer,
and the gate electrode layer. In a modified exemplary embodiment,
an interface layer may be further formed between the active fin 110
and the gate insulation layer.
[0180] Then, the gate electrode layer, the work function control
layer and the gate insulation layer may be planarized until the
upper surfaces of the insulation pattern 400, the separating
pattern SP and the cutting pattern CP may be exposed, thereby
forming a gate insulation pattern 510, a work function control
pattern 520 and a gate electrode 530 that may be sequentially
formed on the active fin 110 and the device isolation layer 120 and
may fill up the gate trench as the gate structure 500. The gate
electrode 530 may be at least partially enclosed by the work
function control pattern 520 in the gate trench. The gate structure
500 may be arranged in the gate trench and may be formed into the
gate line GL extending in the second direction in the cell area
C.
[0181] For example, the gate structure 500, extending from the PMOS
area P, may be sufficiently separated from the gate structure 500,
extending from the NMOS area N, by the separation pattern SP. Thus,
an electric short of the gate structures 500 in the separation
area. PNS may be substantially prevented by the separating pattern
SP.
[0182] The gate structure 500 may be formed substantially by the
same processes as described above in detail with references to
FIGS. 23 to 24D, so to the extent that any further detailed
descriptions of various elements is omitted, it may be assumed that
these elements are at least similar to corresponding elements that
have already been described.
[0183] Thereafter, as illustrated in FIGS. 39 and 40A to 40F, the
contact structure 600, the first interlayer dielectric pattern
ILD1, the second interlayer dielectric pattern ILD2 and the power
rail 700 may be formed substantially by the same processes as
described in detail with references to FIGS. 27 to 32E, so to the
extent that any further detailed descriptions on the method of
forming the contact structure 600, the first interlayer dielectric
pattern ILD1, the second interlayer dielectric pattern ILD2 and the
power rail 700, is omitted, it may be assumed that these elements
are at least similar to corresponding elements that have already
been described.
[0184] Therefore, the gate structure 500 and the junction layer 300
may be sufficiently separated from each other in the separation
area PNS by the separating pattern SP. Thus, the NMOS transistor
and the PMOS transistor may be sufficiently separated, from each
other in the separation area PNS by the separating pattern SP in
spite of the size reduction of the cell area C.
[0185] According to the exemplary embodiments of the present
inventive concept, the cutting pattern CP may be formed in the
power area PA and thus the horizontal growth of the junction layer
300 may be restricted by the cutting pattern CP. Accordingly, the
junction layer 300 in the first cell area C1 may be sufficiently
separated from the junction layer 300 in the second cell area C2
although the power area PA may be reduced in size, thereby
preventing an electric short of the junction layer 300 between the
first and the second cell areas C1 and C2.
[0186] In addition, the gate structure 500 in the first cell area
C1 may also be sufficiently separated from the gate structure 500
in the second cell area C2 by the cutting pattern CP, so that the
gate structure 500 in the first cell area C1 may be, substantially
prevented from being connected with the gate structure 500 in the
second cell area C2 although the power area PA may be reduced in
size, thereby preventing an electric short of the gate structure
500 between the first and the second cell areas C1 and C2.
[0187] Further, the gate structure 500 and the junction layer 300
may be sufficiently separated from each other in the separation
area PNS by the separating pattern SR. Thus, the NMOS transistor
and the PMOS transistor may be sufficiently separated from each
other in the separation area PNS by the separating pattern SP in
spite of the size reduction of the cell area C. The semiconductor
device may be formed into a CMOS device with high reliability and
stability
[0188] Furthermore, a pair of the power contacts 620 may be formed
at both sides of the junction cutting pattern CP2 symmetrically
with respect to the junction cutting pattern CP2 and thus the power
contact 620 in the first cell area C1 may be sufficiently separated
from the power contact 620 in the second cell area C2. Therefore,
the power contact 520 in the first cell area C1 might not be
connected to the power contact 520 in the second cell area C2 due
to the junction cutting pattern CP, thereby preventing electric
short of the power contacts 620.
[0189] Although the power area PA may be reduced in size in
accordance with the size reduction of the recent semiconductor
devices, the gate structure 500 and the junction layer 300 in
different cell area may be sufficiently separated by a unit of the
cell area. Thus, an electric short of the gate structure 500 and
the junction layer 300 may be substantially prevented in spite of
the size reduction of the power area PA.
[0190] For example, when the CMOS device having the cutting pattern
in the power area PA and/or the separating pattern SP in the
separation area PNS may be stored into a standard cell library as a
CMOS standard cell, the logic, device requiting CMOS cells may be
stably manufactured with high reliability by using the CMOS
standard cell and electric shorts in the power area PA and the
separation area PNS may be sufficiently reduced in the logic
device.
[0191] The foregoing is illustrative of exemplary embodiments of
the present invention and the present invention should not be
construed as being limited to the embodiments shown. Although a few
exemplary embodiments have been described, those skilled in the art
will readily appreciate that many modifications are possible in the
exemplary embodiments shown without materially departing from the
novel teachings and aspects of the present invention. Accordingly,
all such modifications are intended to be included within the scope
of the present disclosure.
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