U.S. patent application number 14/483169 was filed with the patent office on 2015-11-19 for carrier channel with element concentration gradient distribution and fabrication method thereof.
The applicant listed for this patent is NATIONAL TSING HUA UNIVERSITY. Invention is credited to Ming-Chang LEE, Chih-Kuo TSENG.
Application Number | 20150332921 14/483169 |
Document ID | / |
Family ID | 54539108 |
Filed Date | 2015-11-19 |
United States Patent
Application |
20150332921 |
Kind Code |
A1 |
LEE; Ming-Chang ; et
al. |
November 19, 2015 |
CARRIER CHANNEL WITH ELEMENT CONCENTRATION GRADIENT DISTRIBUTION
AND FABRICATION METHOD THEREOF
Abstract
The present disclosure provides a carrier channel with an
element concentration gradient distribution. The carrier channel
includes a substrate and a carrier channel structure. The carrier
channel structure is stacked on the substrate, wherein a ratio of a
height and a width of the carrier channel is greater than 1, and
the carrier channel is crystallized from the contact surface by a
rapid melting growth process, thus the carrier channel structure
has the element concentration gradient distribution.
Inventors: |
LEE; Ming-Chang; (Hsinchu
City, TW) ; TSENG; Chih-Kuo; (Taichung City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NATIONAL TSING HUA UNIVERSITY |
HSINCHU |
|
TW |
|
|
Family ID: |
54539108 |
Appl. No.: |
14/483169 |
Filed: |
September 11, 2014 |
Current U.S.
Class: |
257/655 ;
438/492 |
Current CPC
Class: |
H01L 21/02642 20130101;
H01L 21/02381 20130101; H01L 29/36 20130101; H01L 21/0251 20130101;
H01L 21/02532 20130101; H01L 21/02452 20130101; H01L 21/02667
20130101; H01L 21/02535 20130101; H01L 29/1029 20130101; H01L
29/1054 20130101; H01L 21/0245 20130101 |
International
Class: |
H01L 21/02 20060101
H01L021/02; H01L 29/10 20060101 H01L029/10; H01L 29/36 20060101
H01L029/36 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 2014 |
TW |
103116982 |
Claims
1. A fabricating method of a carrier channel with an element
concentration gradient distribution, comprising: providing a
substrate; forming a first isolation layer having a first through
hole on the substrate; forming a stacking layer on the first
isolation layer, wherein the stacking layer is filled into the
first through hole and contacts with the substrate; forming a
second isolation layer on the stacking layer; defining a transfer
pattern on the second isolation layer by a photolithographic
etching process, wherein the second isolation layer having the
transfer pattern is a hard mask; transferring the transfer pattern
onto the stacking layer by a selective etching process and the hard
mask; forming a third isolation layer on the substrate, wherein the
third isolation layer covers the first isolation layer, the
stacking layer, and the hard mask; and executing a rapid melting
growth process for crystallizing the stacking layer into the
carrier channel from a contact surface between the stacking layer
and the substrate, wherein the carrier channel has the element
concentration gradient distribution.
2. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, further comprising:
removing the third isolation layer after forming the carrier
channel.
3. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 2, further comprising:
removing the second isolation layer after removing the third
isolation layer.
4. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 3, further comprising:
removing the first isolation layer after removing the second
isolation layer.
5. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein the
substrate is made of a single-layer material or a multilayer
material which are compatible with a semiconductor process.
6. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein the
substrate is a monocrystalline silicon substrate, a polycrystalline
silicon substrate or an amorphous silicon substrate.
7. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein the
stacking layer is made of germanium-tin or
silicon-germanium-tin.
8. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein the first
isolation layer, the second isolation layer, or the third isolation
layer is an oxide layer.
9. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein the first
isolation layer, the second isolation layer, or the third isolation
layer is a nitride layer.
10. The fabricating method of the carrier channel with the element
concentration gradient distribution of claim 1, wherein a ratio of
a height and a width of the carrier channel is greater than 1.
11. A carrier channel with an element concentration gradient
distribution, comprising: a substrate; and a carrier channel
structure stacked on the substrate and having a contact surface
contacted with the substrate, wherein a ratio of a height and a
width of the carrier channel is greater than 1, and the carrier
channel structure is crystallized from the contact surface by a
rapid melting growth process, thus the carrier channel structure
has the element concentration gradient distribution.
12. The carrier channel with an element concentration gradient
distribution of claim 11, wherein the substrate is made of a
single-layer material or a multilayer material which are compatible
with a semiconductor process.
13. The carrier channel with an element concentration gradient
distribution of claim 11, wherein the substrate is monocrystalline
silicon substrate, a polycrystalline silicon substrate or an
amorphous silicon substrate.
14. The carrier channel with an element concentration gradient
distribution of claim 11, wherein the carrier channel structure is
a germanium-tin carrier channel structure or a
silicon-germanium-tin carrier channel structure.
Description
RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Application
Serial Number 103116982, filed May 14, 2014, which is herein
incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to a carrier channel and a
fabricating method thereof. More particularly, the present
disclosure relates to a carrier channel with an element
concentration gradient distribution and a fabricating method
thereof.
[0004] 2. Description of Related Art
[0005] In semiconductor devices, the carrier concentration in the
active region would affect the performance of the device. How to
control the carrier concentration and the carrier location
precisely is a concerned issue in the semiconductor industry.
[0006] In the semiconductor industry, the thermal diffusion process
and the ion implantation process have been widely used to control
the carrier concentration and the carrier distribution. The thermal
diffusion process promoted the carrier moving from high
concentration region to low concentration region by using high
temperature. But the thermal diffusion process consumes amount of
time and energy, and it would increase the thermal budget and the
production costs of the device significantly. Furthermore, the
thermal diffusion process is only applied to the shallow area of
the device.
[0007] Ion implantation process injects the carriers into the
active region of the device by using an electric field to
accelerate the carriers. The carrier distribution and the carrier
location could be change by adjusting the electric field. Because
the carriers acceleration by the electric field has strong energy,
the carriers would damage the surface lattice of the device and
generate form a lattice defect. Although the lattice defect can be
repaired by executing an annealing process after the ion
implantation process, but the annealing process increases the
production costs of the device.
[0008] As foregoing mention, the conventional techniques should be
improved by additional and time-consuming high temperature
annealing process. However, the high temperature annealing process
always increases the production costs.
SUMMARY
[0009] According to one aspect of the present disclosure, a
fabricating method of a carrier channel with an element
concentration gradient distribution is provided. The method
includes, a substrate is provided. A first isolation layer is
formed on the substrate and the first isolation layer has a first
through hole. A stacking layer is formed on the first isolation
layer, wherein the stacking layer is filled into the first through
hole and contacts with the substrate. A second isolation layer is
formed on the stacking layer. A transfer pattern is defined on the
second isolation layer by a photolithographic etching process,
wherein the second isolation layer having the transfer pattern is a
hard mask. The transfer pattern is transferred onto the stacking
layer by a selective etching process and the hard mask. A third
isolation layer is formed on the substrate, wherein the third
isolation layer covers the first isolation layer, the stacking
layer, and the hard mask. A rapid melting growth process is
executed for crystallizing the stacking layer into the carrier
channel from a contact surface between the stacking layer and the
substrate, wherein the carrier channel has the element
concentration gradient distribution
[0010] According to another aspect of the present disclosure, a
carrier channel with an element concentration gradient distribution
is provided. The carrier channel includes a substrate and a carrier
channel structure. The carrier channel structure is stacked on the
substrate, wherein a ratio of a height and a width of the carrier
channel is greater than 1, and the carrier channel is crystallized
from the contact surface by a rapid melting growth process, thus
the carrier channel structure has the element concentration
gradient distribution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present disclosure can be more fully understood by
reading the following detailed description, with reference made to
the accompanying drawings as follows:
[0012] FIG. 1 is a flowchart of a fabricating method of a carrier
channel with an element concentration gradient distribution
according to one embodiment of the present disclosure;
[0013] FIG. 2 is a schematic diagram of the fabricating method
according to the embodiment of FIG. 1.
[0014] FIG. 3 is a schematic diagram of a carrier channel with an
element concentration gradient distribution according to another
embodiment of the present disclosure; and
[0015] FIG. 4 illustrates a tin concentration distribution
(%)-distance (nm) of the carrier channel of FIG. 3
DETAILED DESCRIPTION
[0016] FIG. 1 is a flowchart of a fabricating method of a carrier
channel with an element concentration gradient distribution
according to one embodiment of the present disclosure and the
fabricating method includes the following steps.
[0017] Step P1, a substrate is provided and the substrate can be
made of a single-layer material or a multilayer material which are
compatible with a semiconductor process. Therefore, the carrier
channel fabricated by the fabricating method can be integrated with
the other semiconductor element on a chip. The substrate can be a
monocrystalline silicon substrate, a polycrystalline silicon
substrate or an amorphous silicon substrate.
[0018] Step P2, a first isolation layer is formed on the substrate
and the first isolation layer has a first through hole. The first
through hole is formed through the first isolation layer. The shape
of the first through hole can be varied on demand. Furthermore, the
first isolation layer can be an oxide layer or a nitride layer.
[0019] Step P3, a stacking layer is formed on the first isolation
layer, wherein the stacking layer is filled into the first through
hole and contacts with the substrate. In step P3, the stacking
layer is formed by a vapor deposition technique, an epitaxy
technique or other techniques which compatible with semiconductor
fabrication process. Moreover, the stacking layer is made of
germanium-tin or silicon-germanium-tin.
[0020] Step P4, a second isolation layer is formed on the stacking
layer. The second isolation layer can be an oxide layer or a
nitride layer.
[0021] Step P5, a transfer pattern is defined on the second
isolation layer by a photolithographic etching process, wherein the
second isolation layer having the transfer pattern is a hard
mask.
[0022] Step P6, the transfer pattern is transferred onto the
stacking layer by a selective etching process and the hard mask.
The stacking layer is protected from the selective etching process
by the hard mask, and the transfer pattern is transferred on the
stacking layer. Hence, the desire shape of the stacking layer is
defined by the transfer pattern.
[0023] Step P7, a third isolation layer is formed on the substrate,
wherein the third isolation layer covers the first isolation layer,
the stacking layer, and the hard mask. The third isolation layer
can be an oxide layer or a nitride layer.
[0024] Step P8, a rapid melting growth process is executed for
crystallizing the stacking layer into the carrier channel from a
contact surface between the stacking layer and the substrate,
wherein the carrier channel has the element concentration gradient
distribution. In step P8, since the covering of the third isolation
layer, the stacking layer is preserved from impurity contamination,
and the element of the stacking layer would not escape easily.
[0025] Further, the fabricating method can includes Steps P9 and
P10. In step P9, the third isolation layer is removed after forming
the carrier channel. Removing the third isolation layer contributes
to remove the second isolation layer.
[0026] Step P10, the second isolation layer is removed after
removing the third isolation layer. Removing the second isolation
layer contributes to fabricate a device which using the carrier
channel of the present disclosure as the active region.
[0027] As mentioned fabricating method in FIG. 1, a carrier channel
with an element concentration gradient distribution is fabricated.
With different requirements of the device, we can choose a suitable
region on the carrier channel with an acceptable carrier
concentration. Therefore, the fabricating method not only
simplifies the process which used to control the carrier
concentration, but also reduces the production cost.
[0028] FIG. 2 is a schematic diagram of the fabricating method
according to the embodiment of FIG. 1. The fabricating method
includes the following steps and detailed described as below. Step
(a), a monocrystailine silicon substrate 100 is provided. Step (b),
a first oxide isolation layer 110 is formed on the monocrystalline
silicon substrate 100 by a vapor deposition technique, and the
first oxide isolation layer 110 has a first through hole 111. The
first through hole 111 pass through the first oxide isolation layer
110. Step (c), a germanium-tin stacking layer 120 is formed on the
first oxide isolation layer 110 by an epitaxy technique, and the
germanium-tin stacking layer 120 is filled into the first through
hole 111 and contacts with the monocrystalline silicon substrate
100. Step (d), a second oxide isolation layer 130 is formed on the
germanium-tin stacking layer 120 by a vapor deposition technique.
Step (e), a transfer pattern is defined on the second oxide
isolation layer 130 by a photolithographic etching process, wherein
the second isolation layer 130 having the transfer pattern is a
hard mask 131.
[0029] Step (f), the transfer pattern is transferred onto the
germanium-tin stacking layer 120 by a selective etching process and
the hard mask 131. The germanium-tin stacking layer 120 is
protected from the selective etching by the hard mask 131, and the
germanium-tin stacking layer 120 has the same shape with the hard
mask 131. Step (g), a third oxide isolation layer 140 is formed on
the monocrystalline silicon substrate 100 by a vapor deposition
technique, and the third oxide isolation layer 140 covers the first
oxide isolation layer 110, the germanium-tin stacking layer 120,
and the hard mask 131. Step (h), a rapid melting growth process is
executed for crystallizing the germanium-tin stacking layer 120
into the carrier channel 121 from a contact surface between the
germanium-tin stacking layer 120 and the monocrystalline silicon
substrate 100, and the carrier channel 121 has the element
concentration gradient distribution. In the carrier channel 121,
the germanium atom concentration is decreased from the contact
surface, and the tin atom concentration is increased from the
contact surface. Since the covering of the covering of the third
oxide isolation layer 140, the germanium-tin stacking layer 120 is
preserved from impurity contamination, and the element of the
stacking layer would not escape easily. Step (i), the third oxide
isolation layer 140 is removed after forming the carrier channel
121. Step (0, the second isolation layer 130 is removed after
removing the third oxide isolation layer 140 and a ratio of a
height (H) and a width (W) of the carrier channel 121 is greater
than 1.
[0030] As mentioned fabricating method, the carrier channel 121 is
fabricated on the monocrystalline silicon substrate 100 by using a
rapid melting growth process. The concentration of germanium atom
and tin atom in the carrier channel 121 are gradually distributed
according to the distance from the contact surface. The fabricating
method of the embodiment doesn't execute additional fabrication
process to control or change the carrier concentration in the
carrier channel 121. The carrier channel 121 can be as applied on a
metal oxide semiconductor transistor, a light-emitting device or a
photo-detector. In addition, the rapid melting growth process is
quick and it contributes to reduce the thermal budget and
production cost.
[0031] FIG. 3 is a schematic diagram of a carrier channel with an
element concentration gradient distribution according to another
embodiment of the present disclosure. The carrier channel with an
element concentration gradient distribution includes a
monocrystalline silicon substrate 200 and a germanium-tin carrier
channel structure 221.
[0032] The monocrystalline silicon substrate 200 is compatible with
a semiconductor process. The germanium-tin carrier channel
structure 221 is stacked on the monocrystalline silicon substrate
200 and having a contact surface contacted with the monocrystalline
silicon substrate 200. The germanium-tin carrier channel structure
221 is crystallized from the contact surface by a rapid melting
growth process, the germanium-tin carrier channel 221 structure has
the element concentration gradient distribution and a ratio of a
height (H) and a width (W) of the germanium-tin carrier channel
structure 221 is greater than 1.
[0033] FIG. 4 illustrates a tin concentration distribution (%)
distance (nm) of the carrier channel of FIG. 3, wherein the tin
distribution a atomic concentration after the rapid melting growth
process and the distance is a point parting from the contact
surface. In the germanium-tin carrier channel structure 221, the
atom concentration of germanium is decreased from the contact
surface, and the atom concentration of tin is increased from the
contact surface. In FIG. 4, the germanium-tin carrier channel (with
10% concentration of tin atom) as an example, at the distance from
the contact surface is 25 nm, the concentration of tin atom is
0.2%. At the distance from the contact surface is 100 nm, the
concentration of tin atom is 0.35%. At the distance from the
contact surface is 190 nm, the concentration of tin atom is promote
to 6.5%. In this embodiment, the height (H) of germanium-tin
carrier channel is only 200 nm, but the distribution variance of
tin atom concentration is more than 30 times,
[0034] As mentioned of the embodiment, the concentration
distribution of the element in the carrier channel is quite
extensive The different distance from the contact surface can be
chosen to be the active region of device with different
performances. In addition, the element concentration of the
germanium-tin carrier channel structure 221 can be adjusted in
order to apply on different fabricating condition. Furthermore, the
monocrystalline silicon substrate 200 has a well thermal
conduction, it provides quick heat dissipation under high speed
operation and can avoid to reduce the efficiency of the device from
the heat accumulation.
[0035] In summary, the present disclosure provides a carrier
channel with an element concentration gradient distribution and a
fabricating method thereof.
[0036] This present disclosure provides a well section in the
carrier channel to fabricate a device with acceptable carrier
concentration by change the distance from the contact surface
without additional process to adjust the carrier concentration.
Because the extensive distribution of the element in the carrier
channel, the carrier channel can be applied in a metal oxide
semiconductor transistor, a light-emitting device or a
photo-detector. Furthermore, the rapid melting growth process is
quick and it contributes to reduce the thermal budget and
production cost.
[0037] Although the present disclosure has been described in
considerable detail with reference to certain embodiments thereof,
other embodiments are possible. Therefore, the spirit and scope of
the appended claims should not be limited to the description of the
embodiments contained herein.
[0038] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present disclosure without departing from the scope or spirit of
the disclosure. In view of the foregoing, it is intended that the
present disclosure cover modifications and variations of this
disclosure provided they fall within the scope of the following
claims.
* * * * *