U.S. patent application number 14/983760 was filed with the patent office on 2016-04-21 for method of manufacturing semiconductor device, semiconductor device and substrate processing apparatus.
This patent application is currently assigned to HITACHI KOKUSAI ELECTRIC INC. The applicant listed for this patent is HITACHI KOKUSAI ELECTRIC INC.. Invention is credited to Tomohide KATO, Norikazu MIZUNO, Takaaki NODA.
Application Number | 20160111466 14/983760 |
Document ID | / |
Family ID | 46063559 |
Filed Date | 2016-04-21 |
United States Patent
Application |
20160111466 |
Kind Code |
A1 |
MIZUNO; Norikazu ; et
al. |
April 21, 2016 |
METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE, SEMICONDUCTOR DEVICE
AND SUBSTRATE PROCESSING APPARATUS
Abstract
An oxide film capable of suppressing reflection of a lens is
formed under a low temperature. A method of manufacturing a
semiconductor device includes (a) forming a lower layer oxide film
on a lens formed on a substrate using a first processing source
containing a first element, a second processing source containing a
second element, an oxidizing source and a catalyst, the lower layer
oxide film having a refractive index greater than that of air and
less than that of the lens; and (b) forming an upper layer oxide
film on the lower layer oxide film using the first processing
source, the oxidizing source and the catalyst, the upper layer
oxide film having a refractive index greater than that of the air
and less than that of the lower layer oxide film.
Inventors: |
MIZUNO; Norikazu; (Toyama,
JP) ; KATO; Tomohide; (Toyama, JP) ; NODA;
Takaaki; (Toyama, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HITACHI KOKUSAI ELECTRIC INC. |
Tokyo |
|
JP |
|
|
Assignee: |
HITACHI KOKUSAI ELECTRIC
INC
Tokyo
JP
|
Family ID: |
46063559 |
Appl. No.: |
14/983760 |
Filed: |
December 30, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14681055 |
Apr 7, 2015 |
9263251 |
|
|
14983760 |
|
|
|
|
14248961 |
Apr 9, 2014 |
9123531 |
|
|
14681055 |
|
|
|
|
13293636 |
Nov 10, 2011 |
8847343 |
|
|
14248961 |
|
|
|
|
Current U.S.
Class: |
438/69 ;
118/704 |
Current CPC
Class: |
C23C 16/52 20130101;
H01L 31/0216 20130101; H01L 31/02327 20130101; H01L 27/14685
20130101; C23C 16/45555 20130101; H01L 27/1462 20130101; H01L
21/02211 20130101; C23C 16/45542 20130101; H01L 21/0228 20130101;
H01L 31/02161 20130101; C23C 16/45557 20130101; C23C 16/45544
20130101; H01L 21/0223 20130101; H01L 21/02205 20130101; C23C
16/45534 20130101; H01L 21/02274 20130101; H01L 21/022 20130101;
C23C 16/40 20130101; H01L 21/02172 20130101; H01L 27/14627
20130101 |
International
Class: |
H01L 27/146 20060101
H01L027/146; C23C 16/52 20060101 C23C016/52 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2010 |
JP |
2010-261571 |
Claims
1. A method of manufacturing a semiconductor device, comprising
forming a metal-containing oxide film on a substrate by performing
a cycle a predetermined number of times, the cycle comprising: (a)
supplying a metal-containing source to the substrate; (b) supplying
an oxidizing source to the substrate; and (c) supplying a catalyst
to the substrate.
2. The method according to claim 1, wherein the metal-containing
source comprises at least one selected from a group consisting of
chloride, fluoride, bromide and iodide.
3. The method according to claim 1, wherein the metal comprises at
least one selected from a group consisting of titanium, hafnium,
and zirconium.
4. The method according to claim 1, wherein the oxidizing source
comprises at least one selected from a group consisting of
H.sub.2O, H.sub.2O.sub.2, a mixed gas of H.sub.2 and O.sub.3 and a
mixed gas of H.sub.2 and O.sub.2.
5. The method according to claim 1, wherein the catalyst comprises
at least one selected from a group consisting of ammonia, pyridine,
trimethylamine, methylamine, triethylamine, aminopyridine,
picoline, piperazine and lutidine.
6. A substrate processing apparatus including: a process chamber
configured to accommodate a substrate; a metal-containing source
supply part configured to supply a metal-containing source into the
process chamber; an oxidizing source supply part configured to
supply an oxidizing source into the process chamber; a catalyst
supply part configured to supply a catalyst into the process
chamber; and a control unit configured to control the
metal-containing source supply part, the oxidizing source supply
part, and catalyst supply part to form a metal-containing oxide
film on the substrate by performing a cycle a predetermined number
of times, the cycle comprising: (a) supplying the metal-containing
source to the substrate; (b) supplying the oxidizing source to the
substrate; and (c) supplying the catalyst to the substrate.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This U.S. non-provisional patent application is a
continuation of U.S. patent application Ser. No. 14/681,055 filed
on Apr. 7, 2015, which is a continuation of U.S. patent application
Ser. No. 14/248,961 filed on Apr. 9, 2014 and issued as U.S. Pat.
No. 9,123,531 on Sep. 1, 2015, which claims priority to U.S. patent
application Ser. No. 13/293,636 filed on Nov. 10, 2011 and issued
on U.S. Pat. No. 8,847,343 on Sep. 30, 2015 which claims priority
under 35 U.S.C. .sctn.119 to Japanese Patent Application No.
2010-261571, filed on Nov. 24, 2010, in the Japanese Patent Office,
the entire contents of which are hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of manufacturing a
semiconductor device, a semiconductor device, and a substrate
processing apparatus.
[0004] 2. Description of the Related Art
[0005] A micro lens configured to collect light for a light
receiving element installed on, for example, a semiconductor
device, has been used in semiconductor devices such as
complementary metal oxide semiconductor (CMOS) image sensors. As
the CMOS image sensor is highly integrated, light-collecting
efficiency of the lens has been promoted to receive more sufficient
incident light through the micro lens.
PRIOR ART DOCUMENTS
Patent Documents
[0006] 1. Japanese Patent Laid-open Publication No.:
2009-177079
[0007] 2. U.S. Pat. No. 6,534,395
SUMMARY OF THE INVENTION
[0008] In order to improve light-collecting efficiency of a lens,
for example, reflection of incident light from a surface of the
lens may be suppressed. Since the reflection is more likely to
occur as a difference in refractive index between media through
which light passes, i.e., air (a low refractive index) and a lens
(a high refractive index), increases, the reflection can be
suppressed by forming a film of a material having a refractive
index therebetween, for example, an oxide film, on the lens to
attenuate the difference in refractive index. Such an oxide film
has been formed on, for example, a lens formed on a substrate,
using a source including a predetermined element and an oxidizing
agent.
[0009] However, since the refractive index is fixedly determined by
a kind of the oxide film and the difference in refractive index
between the media is insufficiently attenuated by only installing
the oxide film having a predetermined refractive index on the lens,
the reflection may be insufficiently suppressed. That is, when an
oxide film having a low refractive index closer to the air is
selected, reflection at an interface with the lens cannot be easily
suppressed, and when an oxide film having a high refractive index
closer to the lens is selected, reflection at an interface with the
air cannot be easily suppressed. In addition, when the lens is
formed of, for example, a resin material, since a substantial
reactivity between the source and the oxidizing agent cannot be
obtained under a low temperature at which no thermal denaturation
occurs from the resin material, the oxide film cannot be easily
formed.
[0010] Therefore, an object of the present invention is to form an
oxide film capable of suppressing reflection of a lens under a low
temperature.
[0011] According to an aspect of the present invention, there is
provided a method of manufacturing a semiconductor device,
including: (a) forming a lower layer oxide film on a lens formed on
a substrate using a first processing source containing a first
element, a second processing source containing a second element, an
oxidizing source and a catalyst, the lower layer oxide film having
a refractive index greater than that of air and less than that of
the lens; and (b) forming an upper layer oxide film on the lower
layer oxide film using the first processing source, the oxidizing
source and the catalyst, the upper layer oxide film having a
refractive index greater than that of the air and less than that of
the lower layer oxide film.
[0012] According to another aspect of the present invention, there
is provided a semiconductor device including: a lens; a lower layer
oxide film disposed on the lens, the lower layer oxide film having
a refractive index greater than that of air and less than that of
the lens and being formed using a first processing source
containing a first element, a second processing source containing a
second element, an oxidizing source and a catalyst; and an upper
layer oxide film disposed on the lower layer oxide film, the upper
layer oxide film having a refractive index greater than that of the
air and less than that of the lower layer oxide film and being
formed using the first processing source, the oxidizing source and
the catalyst.
[0013] According to still another aspect of the present invention,
there is provided a substrate processing apparatus including: a
process chamber configured to accommodate a substrate, the
substrate having a lens disposed thereon; a heating part configured
to heat the substrate; a first processing source supply part
configured to supply a first processing source containing a first
element into the process chamber; a second processing source supply
part configured to supply a second processing source containing a
second element into the process chamber; an oxidizing source supply
part configured to supply an oxidizing source into the process
chamber; a catalyst supply part configured to supply a catalyst
into the process chamber; an exhaust part configured to exhaust an
atmosphere in the process chamber; and a control unit configured to
control the heating part, the first processing source supply part,
the second processing source supply part, the oxidizing source
supply part, the catalyst supply part and the exhaust part to form
a lower layer oxide film on the lens using the first processing
source, the second processing source, the oxidizing source and the
catalyst, the lower layer oxide film having a refractive index
greater than that of air and less than that of the lens, and to
form an upper layer oxide film on the lower layer oxide film using
the first processing source, the oxidizing source and the catalyst,
the upper layer oxide film having a refractive index greater than
that of the air and less than that of the lower layer oxide
film.
[0014] According to a method of manufacturing a semiconductor
device, a semiconductor device and a substrate processing apparatus
of the present invention, an oxide film capable of suppressing
reflection of a lens can be formed under a low temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a substrate processing
apparatus in accordance with a first embodiment of the present
invention;
[0016] FIG. 2 is a view of a process furnace in accordance with the
first embodiment of the present invention, particularly showing a
cross-sectional view of a process chamber;
[0017] FIG. 3 is a view of the process furnace in accordance with
the first embodiment of the present invention, particularly showing
a cross-sectional view taken along line A-A of the process chamber
of FIG. 2;
[0018] FIG. 4 is a flowchart illustrating a substrate processing
process in accordance with the first embodiment of the present
invention;
[0019] FIG. 5 is a gas supply timing chart of the substrate
processing process in accordance with the first embodiment of the
present invention;
[0020] FIGS. 6A and 6B are views for explaining a catalyst reaction
of the substrate processing process in accordance with the first
embodiment of the present invention;
[0021] FIG. 7 is a flowchart illustrating a substrate processing
process in accordance with a second embodiment of the present
invention;
[0022] FIG. 8 is a gas supply timing chart of the substrate
processing process in accordance with the second embodiment of the
present invention;
[0023] FIGS. 9A and 9B are views for explaining a catalyst reaction
of the substrate processing process in accordance with the second
embodiment of the present invention;
[0024] FIGS. 10A and 10B are schematic views showing a refractive
index of a lens installed on a semiconductor device in accordance
with a reference example and the first embodiment; and
[0025] FIGS. 11A and 11B are schematic views showing a refractive
index of a lens installed on a semiconductor device in accordance
with a related art example and the reference example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] <Inventors' Comments>
[0027] First, before describing embodiments of the present
invention, some comments from the inventors will be explained.
[0028] As described above, a semiconductor device such as a CMOS
image sensor is manufactured by forming a light receiving element
configured to convert light into an electrical signal, an
interconnection configured to process the electrical signal, and so
on, on a substrate. For example, a small lens (a micro lens) is
installed over the light receiving element to collect light for the
light receiving device.
[0029] In a conventional semiconductor device shown in FIG. 11A,
incident light 5 which arrives at a resist lens 10, which is a lens
formed of photo resist, partially arrives at a photo diode 30,
which is a light receiving element (a refractive light 7a), and is
partially reflected (a reflective light 6a). Since a difference in
refractive index between the air (refractive index:1.0) and the
resist lens 10 (refractive index:1.6), through which light passes,
is large, reflection can easily occur. For this reason, in the
conventional semiconductor device, light-collecting efficiency of
the resist lens 10 becomes insufficient, and thus, only a weak
electrical signal having a large noise ratio may be obtained.
[0030] On a semiconductor device according to a reference example
shown in FIG. 11B, for example, a SiO film 20 is formed on a resist
lens 10 as one method of suppressing reflection. The difference in
refractive index is attenuated by the SiO film 20 (refractive
index: 1.45) having a refractive index between the air and the
resist lens 10 to somewhat suppress the reflection (reflective
light 6a and 6b) on each film surface.
[0031] However, since the refractive index of the oxide film is
fixedly determined by a kind of the oxide film such as the SiO film
20, the reflection cannot be substantially suppressed by a
predetermined oxide film only. While the refractive index is
adjusted by appropriately selecting the kind of the oxide film to
suppress the reflection at the film surface, when the oxide film
having a refractive index closer to the air is formed, the
reflection at a surface of the resist lens 10 cannot be easily
suppressed, and when the oxide film having a refractive index
closer to the resist lens 10 is formed, the reflection at an
interface with the air cannot be easily suppressed.
[0032] In addition, in the semiconductor device according to the
reference example, there have been problems involving a temperature
upon film forming. The oxide film is formed on the lens of the
substrate by supplying a source and an oxidizing source into a
process chamber in which the substrate is accommodated and reacting
the source and the oxidizing source. However, as described above,
when the lens is formed of a resin material such as photo resist,
under a temperature at which no thermal denaturation occurs from
the resin material, for example, a low temperature equal to or
lower than 200.degree. C., reaction between the source and the
oxidizing source cannot be sufficiently generated and the oxide
film cannot be easily formed.
[0033] Therefrom, the inventors have performed research on means
for solving these problems. As a result, it has been ascertained
that, when an oxide film is formed, reflection can be suppressed by
varying a refractive index of the oxide film in a thickness
direction. In addition, it has been ascertained that the oxide film
can be formed even under a low temperature by supplying catalyst or
using plasma. The present invention is based on these discoveries
by the inventors.
First Embodiment
[0034] A configuration of a substrate processing apparatus in
accordance with a first embodiment of the present invention will be
described below.
[0035] (1) Entire Configuration of Substrate Processing
Apparatus
[0036] FIG. 1 is a perspective view of a substrate processing
apparatus 101 of the embodiment.
[0037] As shown in FIG. 1, the substrate processing apparatus 101
in accordance with the embodiment includes a housing 111. In order
to convey a wafer 200, which is a substrate, into/from the housing
111, a cassette 110, which is a wafer carrier (a substrate
receiving vessel) configured to receive a plurality of wafers 200,
is used. A cassette loading/unloading port (a substrate-receiving
vessel loading/unloading port, not shown), which is an opening
through the cassette 110 is conveyed into/from the housing 111, is
installed in the front of the housing 111. A cassette stage 114 (a
substrate-receiving vessel delivery platform) is installed inside
the cassette loading/unloading port inside the housing 111. The
cassette 110 is placed on the cassette stage 114 by a conveyance
apparatus in a factory (not shown), is configured to be unloaded to
the outside of the housing 111 from above the cassette stage
114.
[0038] The cassette 110 is configured to be placed on the cassette
stage 114 by the conveyance apparatus in the factory such that the
wafer 200 in the cassette 110 is in a vertical posture and a wafer
entrance of the cassette 110 is directed upward. The cassette stage
114 is configured such that the cassette 110 is rotated 90.degree.
toward a rear side of the housing 111 to place the wafer 200 in the
cassette 110 in a horizontal posture, and the wafer entrance of the
cassette 110 is directed to the rear side in the housing 111.
[0039] A cassette shelf 105 (a substrate receiving vessel placing
shelf) is installed at a substantially center portion in the
housing 111 in a forward-backward direction. The cassette shelf 105
is configured to store a plurality of cassettes 110 in multiple
rows and multiple columns. A transfer shelf 123, in which the
cassette 110 conveyed by a wafer transfer mechanism 125 (described
later) is received, is installed at the cassette shelf 105. In
addition, a preliminary cassette shelf 107 is configured to be
installed over the cassette 114 to store a preliminary cassette
200.
[0040] A cassette conveyance apparatus 118 (a substrate receiving
vessel conveyance apparatus) is installed between the cassette
stage 114 and the cassette shelf 105. The cassette conveyance
apparatus 118 includes a cassette elevator 118a (a substrate
receiving vessel elevation mechanism) configured to go up/down with
holding the cassette 110, and a cassette conveyance mechanism 118b
(a substrate receiving vessel conveyance mechanism), which is a
conveyance mechanism that is horizontally movable while holding the
cassette 110. With a continuous operation of the cassette elevator
118a and the cassette conveyance mechanism 118b, the cassette 110
is configured to be conveyed to a predetermined position of the
cassette shelf 105 other than the cassette stage 114 and the
transfer shelf 123, i.e., between the preliminary cassette shelf
107 and the transfer shelf 123.
[0041] A wafer transfer mechanism 125 (a substrate transfer
mechanism) is installed behind the cassette shelf 105. The wafer
transfer mechanism 125 includes a wafer transfer apparatus 125a (a
substrate transfer apparatus) configured to horizontally rotate or
straightly move the wafer 200, and a wafer transfer apparatus
elevator 125b (a substrate transfer apparatus elevation mechanism)
configured to raise/lower the wafer transfer apparatus 125a. In
addition, the wafer transfer apparatus 125a includes tweezers 125c
(a substrate holder) configured to hold the wafer 200 in a
horizontal posture. With a continuous operation of the wafer
transfer apparatus 125a and the wafer transfer apparatus elevator
125b, the wafer 200 is picked up from the cassette 110 on the
transfer shelf 123 to be charged on a boat 217 (a substrate holder,
described later) (wafer charging), or the wafer 200 is discharged
from the boat 217 (wafer discharging), receiving the wafer 200 into
the cassette 110 on the transfer shelf 123.
[0042] The process furnace 202 is installed at a rear upper side of
the housing 111. An opening is formed at a lower end of the process
furnace 202, and configured to be opened/closed by a furnace port
shutter 147 (a furnace port opening/closing mechanism). In
addition, a configuration of the process furnace 202 will be
described later.
[0043] A transfer chamber 124, which is a space for
charging/discharging the wafer 200 from the cassette 110 on the
transfer shelf 123 to the boat 217 (the substrate holder), is
installed under the process furnace 202. A boat elevator 115 (a
substrate holder elevation mechanism), which is an elevation
mechanism configured to raise/lower the boat 217 to load/unload the
boat 217 into/from the process furnace 202, is installed in the
transfer chamber 124. An arm 128, which is a connecting tool, is
installed at an elevation frame of the boat elevator 115. A seal
cap 219, which is a furnace port cover configured to vertically
support the boat 217 and to hermetically close the lower end of the
process furnace 202 when the boat 217 is raised by the boat
elevator 115, is installed on the arm 128 in a horizontal
posture.
[0044] The boat 217 includes a plurality of holding members, and is
configured to hold a plurality of wafers 200 (for example, about 25
to 125) in a multi-stage in a state where the plurality of wafers
200 are concentrically aligned in a vertical direction and held in
a horizontal posture.
[0045] A clean unit 134a including a supply fan and an
anti-vibration filter is installed over the cassette shelf 105. The
clean unit 134a is configured to flow clean air of a purified
atmosphere into the housing 111.
[0046] In addition, a clean unit (not shown) including a supply fan
for supplying clean air and an anti-vibration filter is installed
at a left end of the housing 111 opposite to the wafer transfer
apparatus elevator 125b and the boat elevator 115. The clean air
injected from the clean unit is suctioned into an exhaust apparatus
(not shown) to be exhausted to the outside of the housing 111,
after flowing through the wafer transfer apparatus 125a and the
boat 217.
[0047] (2) Operation of Substrate Processing Apparatus
[0048] Hereinafter, an operation of the substrate processing
apparatus 101 in accordance with the embodiment will be
described.
[0049] First, the cassette 110 is placed on the cassette stage 114
such that the cassette 110 is loaded through the cassette
loading/unloading port (not shown) by the conveyance apparatus in
the factory, the wafer is in a vertical posture, and the wafer
entrance of the cassette 110 is directed upward. Then, the cassette
110 is rotated 90.degree. toward a rear side of the housing 111 by
the cassette stage 114. As a result, the wafer 200 in the cassette
110 is in a horizontal posture, and the wafer entrance of the
cassette 110 is directed to a rear side in the housing 111.
[0050] Next, the cassette 110 is automatically conveyed and
delivered to a designated shelf position of the cassette shelf 105
(except for the transfer shelf 123) or the preliminary cassette
shelf 107 by the cassette conveyance apparatus 118, temporarily
stored, and then, transferred to the transfer shelf 123 from the
cassette shelf 104 or the preliminary cassette shelf 107 or
directly conveyed to the transfer shelf 123.
[0051] When the cassette 110 is transferred to the transfer shelf
123, the wafer 200 is picked up from the cassette 110 through the
wafer entrance by the tweezers 125c of the wafer transfer apparatus
125a to be charged to the boat 217 at a rear side of the transfer
chamber 124 by a continuous operation of the wafer transfer
apparatus 125a and the wafer transfer apparatus elevator 125b
(wafer charging). The wafer transfer mechanism 125, which delivered
the wafer 200 to the boat 217, returns to the cassette 110, and
then charges the next wafer 200 to the boat 217.
[0052] When a predetermined number of wafers 200 are charged to the
boat 217, the furnace port shutter 147 closing the lower end of the
process furnace 202 is opened. Next, as the seal cap 219 is raised
by the boat elevator 115, the boat 217 holding the group of the
wafer 200 is loaded into the process furnace 202 (boat loading).
After the loading, arbitrary processing is performed on the wafer
200 in the process furnace 202. Such processing will be described
later. After the processing, the wafer 200 and the cassette 110 are
unloaded to the outside of the housing 111 in reverse sequence of
the above sequence.
[0053] (3) Configuration of Process Furnace
[0054] Next, a configuration of the process furnace 202 in
accordance with the embodiment will be generally described with
reference to FIGS. 2 and 3. FIG. 2 is a configuration view of the
process furnace 202 of the substrate processing apparatus 101 shown
in FIG. 1, particularly showing a cross-sectional view of a process
chamber 201. In addition, FIG. 3 is a cross-sectional view taken
along line A-A of the process chamber 201 shown in FIG. 2.
[0055] (Process Chamber)
[0056] The process furnace 202 in accordance with the embodiment is
configured as a batch-type vertical hot-wall process furnace. The
process furnace 202 includes a reaction tube 203 and a manifold
209. The reaction tube 203 is formed of a heat resistant material
such as quartz (SiO.sub.2) or silicon carbide (SiC), and has a
cylindrical shape with an upper end closed and a lower end opened.
The manifold 209 is formed of a metal material such as SUS, and has
a cylindrical shape with upper and lower ends opened. The reaction
tube 203 is vertically supported from the lower end side thereof by
the manifold 209. The reaction tube 203 is disposed concentrically
with the manifold 209. An O-ring 220, which is a sealing member, is
installed between the reaction tube 203 and the manifold 209. A
lower end of the manifold 209 is configured to be hermetically
sealed by the seal cap 219 when the boat elevator 115 is raised. An
O-ring 220b, which is a sealing member configured to hermetically
seal the inside of the process chamber 201, is installed between
the lower end of the manifold 209 and the seal cap 219.
[0057] The process chamber 201 in which the wafer 200, which is a
substrate, is accommodated is formed in the reaction tube 203 and
the manifold 209. The boat 217, which is a substrate holder, is
configured to be inserted into the process chamber 201 from a lower
side thereof. Inner diameters of the reaction tube 203 and the
manifold 209 are configured to be larger than a maximum outline of
the boat 217 to which the wafer 200 is charged.
[0058] The boat 217 is formed of a heat resistant material such as
quartz or silicon carbide, and is configured to hold the plurality
of wafers 200 in a multi-stage in a state where the plurality of
wafers 200 are concentrically aligned and held in a horizontal
posture. In addition, an insulating member 218 formed of a heat
resistant material such as quartz or silicon carbide is installed
at a lower part of the boat 217 to reduce heat transfer from a
heater 207 (described later) to the seal cap 219. Further, the
insulating member 218 may be constituted by a plurality of
insulating plates formed of a heat resistant material such as
quartz or silicon carbide, and an insulating plate holder
configured to support the plates in a horizontal posture in a
multi-stage.
[0059] The seal cap 219, which is a furnace port cover configured
to hermetically close a lower end opening of the reaction tube 203,
is installed under the reaction tube 203. The seal cap 219 abuts
the lower end of the reaction tube 203 from a vertical lower side
thereof. The seal cap 219 is formed of a metal material such as SUS
and has a disc shape. An O-ring 220b, which is a seal member in
contact with the lower end of the manifold 209, is installed at an
upper surface of the seal cap 219.
[0060] A rotary mechanism 267 configured to rotate the boat 217 is
installed at the seal cap 219 opposite to the process chamber 201.
A rotary shaft 255 of the rotary mechanism 267 is connected to the
boat 217 through the seal cap 219 to rotate the boat 217, thus
rotating the wafer 200. The seal cap 219 is configured to be
vertically raised/lowered by the boat elevator 115, which is an
elevation mechanism vertically installed outside the reaction tube
203 such that the boat 217 can be loaded/unloaded into/from the
process chamber 201.
[0061] The heater 207, which is a heating unit having a cylindrical
shape concentric with the reaction tube 203, is installed at an
outer circumference of the reaction tube 203. The heater 207 is
supported by a heater base (not shown), which is a holding plate,
to be installed vertically. In addition, the heater 207 functions
as an activation mechanism configured to activate a gas using
heat.
[0062] A temperature sensor 263, which is a temperature detector,
is installed in the reaction tube 203, and a conduction state to
the heater 207 is adjusted based on temperature information
detected by the temperature sensor 263 such that a temperature in
the process chamber 201 becomes a desired temperature distribution.
The temperature sensor 263 has an L shape similar to nozzles 400a,
400b, 400c and 400d (described later), and is installed along an
inner wall of the reaction tube 203.
[0063] Mainly, the process chamber 201 is constituted by the
reaction tube 203, the manifold 209 and the seal cap 219, and the
process furnace 202 is constituted by the heater 207, the reaction
tube 203, the manifold 209 and the seal cap 219.
[0064] (Nozzle)
[0065] A first nozzle 400a, a second nozzle 400b, a third nozzle
400c and a fourth nozzle 400d are installed at a lower portion of
the reaction tube 203 in the process chamber 201 to pass through a
sidewall of the manifold 209. Each of the nozzles 400a, 400b, 400c
and 400d is constituted as an L-shaped long nozzle.
[0066] Specifically, the nozzles 400a, 400b, 400c and 400d are
installed in a vertical posture in an arc-shaped space between the
inner wall of the reaction tube 203 and the wafer 200 from a lower
portion to an upper portion of the inner wall of the reaction tube
203 upward in a stacking direction of the wafers 200. Gas supply
holes 401a, 401b, 401c and 401d configured to supply a gas are
installed at side surfaces of the nozzles 400a, 400b, 400c and
400d, respectively. The gas supply holes 401a, 401b, 401c and 401d
are opened toward a center of the reaction tube 203. The plurality
of gas supply holes 401a, 401b, 401c and 401d are installed from
the lower portion to the upper portion of the reaction tube 203,
each of which has the same opening area at the same opening
pitch.
[0067] In addition, as shown in FIG. 3, the nozzles 400a, 400b,
400c and 400d are installed at positions opposite to the
temperature sensor 263, for example, with the wafer 200 interposed
therebetween. However, in FIG. 2, in order to show structures of
the nozzles 400a, 400b, 400c and 400d, for the sake of convenience,
the third nozzle 400c and the fourth nozzle 400d and their
subsidiary gas supply pipes 410c and 410d are shown at a right side
of the drawing opposite to the first nozzle 400a and the second
nozzle 400b.
[0068] (First Processing Source Supply Part)
[0069] A downstream end of a first processing source gas supply
pipe 410a configured to supply a Si-containing gas, which is a
first processing source including silicon (Si) as a first element,
for example, hexachlorodisilane (HCD: Si.sub.2Cl.sub.6) gas, is
connected to an upstream end (a lower portion) of the first nozzle
400a. An HCD supply source (not shown) configured to supply a
liquid source, which is in a liquid phase at room temperature, a
liquid mass flow controller 411a, which is a flow rate controller
(a flow rate control unit), a valve 412a, which is an
opening/closing valve, an evaporator 415a, and a valve 413a, which
is an opening/closing valve, are installed at the first processing
source supply pipe 410a in a sequence from an upstream side
thereof.
[0070] A downstream end of a carrier gas supply pipe 420a
configured to supply a carrier gas such as nitrogen (N.sub.2) gas
supplied into the process chamber 201 with HCD gas generated in the
evaporator 415a is connected to the evaporator 415a. A carrier gas
supply source (not shown), a mass flow controller 421a, which is a
flow rate controller (a flow rate control unit), and a valve 422a,
which is an opening/closing valve, are installed at the carrier gas
supply pipe 420a in a sequence from the upstream side thereof. When
the valve 412a is opened and liquid HCD whose flow rate is
controlled by a liquid mass flow controller 411a is supplied into
the evaporator 415a, the evaporator 415a is configured to heat the
supplied HCD to generate a vaporized gas of the HCD. From the state
in which the HCD gas is generated in the evaporator 415a, the valve
422a is opened, the carrier gas whose flow rate is controlled by
the mass flow controller 421a is supplied into the evaporator 415a,
and the valve 413a is opened, such that the HCD gas can be supplied
into the process chamber 201 with the carrier gas.
[0071] A downstream end of a purge gas supply pipe 430a configured
to supply a purge gas such as N.sub.2 gas is connected to the first
processing source supply pipe 410a at a lower side of the valve
413a. A purge gas supply source (not shown), a mass flow controller
431a, which is a flow rate controller (a flow rate control unit),
and a valve 432a, which is an opening/closing valve, are installed
at the purge gas supply pipe 430a in a sequence from the upstream
side thereof. As the valve 432a is opened, the purge gas can be
supplied into the process chamber 201 from the purge gas supply
source while controlling a flow rate by the mass flow controller
431a. For example, after completion of supply of the HCD gas, as
the purge gas is supplied while exhausting the inside of the
process chamber 201, the HCD gas remaining in the process chamber
201 can be eliminated.
[0072] A first processing source supply part configured to supply a
first processing source into the process chamber 201 is mainly
constituted by the first processing source supply pipe 410a, the
HCD supply source, the liquid mass flow controller 411a, the valve
412a, the evaporator 415a, the valve 413a, the carrier gas supply
pipe 420a, the carrier gas supply source, the mass flow controller
421a, the valve 422a, the first nozzle 400a and the gas supply hole
401a.
[0073] (Second Processing Source Supply Part)
[0074] A downstream end of a second processing source supply pipe
410b configured to supply a Ti-containing gas as a second
processing source including titanium (Ti) as a second element, for
example, tetrachlorotitanium (TiCl.sub.4) gas, is connected to an
upstream end (a lower portion) of the second nozzle 400b. A
TiCl.sub.4 supply source (not shown) configured to supply
TiCl.sub.4 as a liquid source, which is liquid at room temperature,
a liquid mass flow controller 411b, which is a flow rate controller
(a flow rate control unit), a valve 412b, which is an
opening/closing valve, an evaporator 415b, and a valve 413b, which
is an opening/closing valve, are installed at the second processing
source supply pipe 410b in a sequence from the upstream side
thereof.
[0075] A downstream end of a carrier gas supply pipe 420b
configured to supply a carrier gas such as N.sub.2 gas supplied
into the process chamber 201 with TiCl.sub.4 gas generated in the
evaporator 415b is connected to the evaporator 415b. A carrier gas
supply source (not shown), a mass flow controller 421b, which is a
flow rate controller (a flow rate control unit), and a valve 422b,
which is an opening/closing valve, are installed at the carrier gas
supply pipe 420b in sequence from the upstream side thereof.
Similar to the case of the first processing source, as the
respective parts are operated, the TiCl.sub.4 gas generated in the
evaporator 415b can be supplied into the process chamber 201 with
the carrier gas.
[0076] A downstream end of a purge gas supply pipe 430b configured
to supply a purge gas such as N.sub.2 gas is connected to the
second processing source supply pipe 410b at a downstream side of
the valve 413b. A purge gas supply source (not shown), a mass flow
controller 431b, which is a flow rate controller (a flow rate
control unit), and a valve 432b, which is an opening/closing valve,
are installed at the purge gas supply pipe 430b in a sequence from
the upstream side thereof. Similar to the case of the purge gas, as
the respective parts are operated, the purge gas can be supplied
into the process chamber 201, and thus, the TiCl.sub.4 gas
remaining in the process chamber 201 can be eliminated.
[0077] A second processing source supply part configured to supply
a second processing source into the process chamber 201 is mainly
constituted by the second processing source supply pipe 410b, the
TiCl.sub.4 supply source, the liquid mass flow controller 411b, the
valve 412b, the evaporator 415b, the valve 413b, the carrier gas
supply pipe 420b, the carrier gas supply source, the mass flow
controller 421b, the valve 422b, the second nozzle 400b and the gas
supply hole 401b.
[0078] (Oxidizing Source Supply Part)
[0079] A downstream end of an oxidizing source supply pipe 410c
configured to supply an oxidizing source such as an oxygen (O)
containing gas, for example, vapor (H.sub.2O gas), is connected to
an upstream end (a lower portion) of the third nozzle 400c.
[0080] A H.sub.2O gas supply source (not shown) configured to
supply H.sub.2O gas, a mass flow controller 411c, which is a flow
rate controller (a flow rate control unit), and a valve 412c, which
is an opening/closing valve, are installed at the oxidizing source
supply pipe 410c in a sequence from the upstream side thereof.
Meanwhile, when the H.sub.2O gas is supplied, oxygen (O.sub.2) gas
and hydrogen (H.sub.2) gas may be supplied into a pyrogenic furnace
to generate H.sub.2O gas.
[0081] A downstream end of an inert gas supply pipe 420c configured
to supply an inert gas such as N.sub.2 gas is connected to a
downstream side of the valve 412c. An inert gas supply source (not
shown), a mass flow controller 421c, which is a flow rate
controller (a flow rate control unit), and a valve 422c, which is
an opening/closing valve, are installed at the inert gas supply
pipe 420c in sequence from the upstream side thereof. As the valves
412c and 422c are opened, the H.sub.2O whose gas flow rate is
controlled by the mass flow controller 412c can be supplied into
the process chamber 201 with the inert gas, which is a carrier gas
whose flow rate is controlled by the mass flow controller 422c.
[0082] In addition, in a state in which the valve 422c is opened
with the valve 412c closed and the flow rate is controlled by the
mass flow controller 421c, the inert gas is supplied into the
process chamber 201 as a purge gas so that the H.sub.2O gas, etc.,
remaining in the process chamber 201 can be eliminated. Further,
similar to the case of the first processing source and the second
processing source, the purge gas supply pipe configured to supply
the purge may be installed separately from the inert gas supply
pipe 420c configured to supply the carrier gas.
[0083] The oxidizing source supply part configured to supply the
oxidizing source into the process chamber 201 is mainly constituted
by the oxidizing source supply pipe 410c, the H.sub.2O gas supply
source, the mass flow controller 411c, the valve 412c, the inert
gas supply pipe 420c, the inert gas supply source, the mass flow
controller 421c, the valve 422c, the third nozzle 400c and the gas
supply hole 401c.
[0084] (Catalyst Supply Part)
[0085] A downstream end of a catalyst supply pipe 410d configured
to supply a catalyst such as ammonia (NH.sub.3) gas is connected to
an upstream end (a lower portion) of the fourth nozzle 400d. An
NH.sub.3 gas supply source (not shown) configured to supply
NH.sub.3 gas, a mass flow controller 411d, which is a flow rate
controller (a flow rate control unit), and a valve 412d, which is
an opening/closing valve, are installed at the catalyst supply pipe
410d in a sequence from the upstream side thereof.
[0086] A downstream end of an inert gas supply pipe 420d configured
to supply an inert gas such as N.sub.2 gas is connected to a
downstream side of the valve 412d. An inert gas supply source (not
shown), a mass flow controller 421d, which is a flow rate
controller (a flow rate control unit), and a valve 422d, which is
an opening/closing valve, are installed at the inert gas supply
pipe 420d in a sequence from the upstream side thereof. Similar to
the case of the oxidizing source, as the respective operations are
executed, the NH.sub.3 gas can be supplied into the process chamber
201 with the inert gas, which is a carrier gas.
[0087] In addition, as the inert gas is supplied into the process
chamber 201 as a purge gas, the NH.sub.3 gas remaining in the
process chamber 201 can be eliminated. Further, similar to the case
of the first processing source or the second processing source, the
purge gas supply pipe configured to supply the purge gas may be
installed separately from the inert gas supply pipe 420d configured
to supply the carrier gas.
[0088] The catalyst supply part configured to the catalyst into the
process chamber 201 is mainly constituted by the catalyst supply
pipe 410d, the NH.sub.3 gas supply source, the mass flow controller
411d, the valve 412d, the inert gas supply pipe 420d, the inert gas
supply source, the mass flow controller 421d, the valve 422d, the
fourth nozzle 400d and the gas supply hole 401d.
[0089] (Exhaust Part)
[0090] A gas exhaust pipe 231 configured to exhaust an atmosphere
in the process chamber 201 is installed at the reaction tube 203. A
vacuum pump 246, which is a vacuum exhaust apparatus, is connected
to the gas exhaust pipe 231 via a pressure sensor 245, which is a
pressure detector (a pressure detection part) configured to detect
a pressure in the process chamber 201 and an automatic pressure
controller (APC) valve 243, which is a pressure regulator (a
pressure regulation part), and is configured such that the pressure
in the process chamber 201 is vacuum-exhausted to a predetermined
pressure (a level of vacuum). The APC valve 243 is an
opening/closing valve capable of opening/closing the valve to
perform vacuum exhaust/vacuum exhaust stoppage of the inside of the
process chamber 201 and adjusting a valve opening angle to adjust
the pressure.
[0091] In addition, as shown in FIG. 3, the gas exhaust pipe 231 is
installed at, for example, a lower sidewall of the reaction tube
203 between the first nozzle 400a and the temperature sensor 263.
However, in FIG. 2, in order to show structures of the gas exhaust
pipe 231, the APC valve 243, the vacuum pump 246 and the pressure
sensor 245, for the sake of convenience, the configuration
including the gas exhaust pipe 231 is shown at a right side of the
drawing opposite to the first nozzle 400a and the second nozzle
400b.
[0092] The exhaust part is mainly constituted by the gas exhaust
pipe 231, the APC valve 243, the vacuum pump 246 and the pressure
sensor 245.
[0093] (Control Unit)
[0094] The controller 280, which is a control unit, is connected to
the liquid mass flow controllers 411a, 411b and 411c, the mass flow
controllers 421a, 431a, 421b, 431b, 421c, 431c, 411d and 421d, the
valves 412a, 413a, 422a, 432a, 412b, 413b, 422b, 432b, 412c, 413c,
422c, 432c, 412d and 422d, the APC valve 243, the pressure sensor
245, the vacuum pump 246, the heater 207, the temperature sensor
263, the rotary mechanism 267, the boat elevator 115, and so on.
The controller 280 controls the flow rate adjusting operations of
various gases by the liquid mass flow controllers 411a, 411b and
411c and the mass flow controllers 421a, 431a, 421b, 431b, 421c,
431c, 411d and 421d, the opening/closing operations of the valves
412a, 413a, 422a, 432a, 412b, 413b, 422b, 432b, 412c, 413c, 422c,
432c, 412d and 422d, the pressure regulating operations based on
the opening/closing of the APC valve 243 and the pressure sensor
245, the temperature control operation of the heater 207 based on
the temperature sensor 263, the start/stop of the vacuum pump 246,
the rotational speed adjusting operation of the rotary mechanism
267, the elevating operation of the boat elevator 115, and so
on.
[0095] (4) Substrate Processing Process
[0096] Next, the substrate processing process in accordance with
the embodiment will be described. The substrate processing process
in accordance with the embodiment, which is one process of a
process of manufacturing a semiconductor device such as a CMOS
image sensor, is performed by the process furnace 202, and similar
to FIG. 10b, which will be described in detail, a silicon titanium
oxide (SiTiO) film 21 having a high refractive index and a silicon
oxide (SiO) film 20 having a low refractive index are sequentially
formed on the resist lens 10. In addition, the SiO film is a
silicon oxide film having an arbitrary composition ratio including
SiO.sub.2.
[0097] A film forming method includes a chemical vapor deposition
(CVD) method in which a plurality of gases containing a plurality
of elements constituting a film to be formed are simultaneously
supplied, and an atomic layer deposition (ALD) method in which a
plurality of gases containing a plurality of elements constituting
a film to be formed are alternately supplied. Then, the silicon
oxide (SiO) film, etc., is formed by controlling supply conditions
such as a gas supply flow rate, a gas supply time, a plasma power,
and so on, upon the gas supply.
[0098] In these film forming methods, for example, supply
conditions are controlled such that a composition ratio of the film
becomes N/Si.apprxeq.1.33, which is a stoichiometric composition,
when a titanium nitride (SiN) film is formed, and a composition
ratio of the film becomes O/Si.apprxeq.2, which is a stoichiometric
composition, when a silicon oxide (SiO) film is formed.
[0099] In addition, supply conditions may be controlled such that a
composition of a film to be formed becomes another predetermined
composition ratio different from a stoichiometric composition. That
is, the supply conditions may be controlled such that at least one
element among the plurality of elements constituting the film to be
formed exceeds the stoichiometric composition more than another
element. As described above, the film forming may be performed
while controlling a ratio of the plurality of elements constituting
the film to be formed (the composition ratio of the film).
[0100] Further, the term "metal film" means a film formed of a
conductive material containing metal atoms, and includes, in
addition to a conductive metal mono-film formed of a metal monomer,
a conductive metal nitride film, a conductive metal oxide film, a
conductive metal oxynitride film, a conductive metal complex film,
a conductive metal alloy film, a conductive metal silicide film,
and so on. For example, the titanium nitride layer is a conductive
metal nitride film.
[0101] Hereinafter, the substrate processing process in accordance
with the embodiment will be described in detail with reference to
FIGS. 4 and 5. FIG. 4 is a flowchart of the substrate processing
process performed by the process furnace 202. In addition, FIG. 5
is a timing chart showing each gas supply timing when supply of the
respective gases is alternately repeated according to the
embodiment. In the following description, operations of the
respective parts constituting the process furnace 202 shown in FIG.
2 are controlled by the controller 280.
[0102] <Substrate Loading Process S101>
[0103] First, the plurality of wafers 200 on which the resist
lenses 10 are previously formed are charged to the boat 217 (wafer
charging). Then, the boat 217 on which the plurality of wafers 200
are held is raised by the boat elevator 115 to be loaded into the
process chamber 201 (boat loading). In this state, the seal cap 219
seals the lower end of the manifold 209 via the O-ring 220b. In the
substrate loading process S101, the valves 432a and 432b of the
purge gas supply pipes 430a and 430b and the valves 422c and 422d
of the inert gas supply pipes 420c and 420d may be opened to
continuously supply the purge gas such as N.sub.2 gas into the
process chamber 201.
[0104] <Pressure Reduction Process S102 and Temperature Increase
Process S103>
[0105] Next, the valves 432a, 432b, 422c and 422d are closed, and
the inside of the process chamber 201 is exhausted by the vacuum
pump 246. At this time, as an opening angle of the APC valve 243 is
adjusted, the inside of the process chamber 201 is under a
predetermined pressure. In addition, the temperature in the process
chamber 201 is controlled by the heater 207 such that the wafer 200
arrives at a desired temperature, for example, room temperature to
200.degree. C., more preferably, room temperature to 150.degree.
C., for example, 100.degree. C. At this time, a conduction state to
the heater 207 is feedback controlled based on temperature
information detected by the temperature sensor 263 such that the
inside of the process chamber 201 arrives at a desired temperature
distribution. Then, the boat 217 is rotated by the rotary mechanism
267 to initiate rotation of the wafer 200.
[0106] <Lower Layer Oxide Film Forming Process S104a to
S106>
[0107] Next, processes S104a to S106 of FIG. 4 are performed to
form a SiTiO film 21, which is a lower layer oxide film (a high
refractive index oxide film), on the resist lens 10 formed on the
wafer 200 (see FIG. 10B). The lower layer oxide film forming
process S104a to S106 includes a first cycle process of setting
processes S104a to S104d as one cycle and performing the cycle a
predetermined number of times S104e, and a second cycle process of
setting processes S105a to S105d as one cycle and performing the
cycle a predetermined number of times S105e. The first cycle
process S104a to S104e and the second cycle process S105a to S105e
are set as one set, and the set is performed with a predetermined
combination a predetermined number of times (S106), forming the
SiTiO film 21. In addition, the SiTiO film 21 is a complex oxide
film of Si and Ti having an arbitrary composition ratio.
Hereinafter, the first cycle process S104a to S104e and the second
cycle process S105a to S105e will be described in detail.
[0108] <First Processing Source and Catalyst Supply Process
S104a>
[0109] In the first processing source and catalyst supply process
S104a of the first cycle process S104a to S104e, HCD gas, which is
a first processing source, and NH.sub.3 gas, which is a catalyst,
are supplied into the process chamber 201.
[0110] Specifically, first, before initiating supply of the HCD
gas, the HCD gas is previously generated in the evaporator 415a.
That is, the valve 412a is opened, and liquid HCD is supplied into
the evaporator 415a while controlling a flow rate by the liquid
mass flow controller 411a, generating the HCD gas. When the HCD gas
is supplied, the valve 422a is opened, and the carrier gas is
supplied into the evaporator 415a while controlling a flow rate by
the mass flow controller 421a. In addition, the valve 413a is
opened, and the generated HCD gas is supplied into the process
chamber 201 with the carrier gas.
[0111] In addition, the valves 412d and 422d are opened, and the
NH.sub.3 gas is supplied into the process chamber 201 with the
inert gas, which is a carrier gas, while controlling flow rates by
the mass flow controllers 411d and 421d, respectively.
[0112] When the HCD gas and the NH.sub.3 gas are supplied into the
process chamber 201, an opening angle of the APC valve 243 is
adjusted to bring the inside of the process chamber 201 to a
predetermined pressure, for example, 10 Torr. A flow rate ratio of
the HCD gas and the NH.sub.3 gas is a ratio of a flow rate (sccm)
of the HCD gas/a flow rate (sccm) of the NH.sub.3 gas, for example,
0.01 to 100, more preferably 0.05 to 10. A supply time of the HCD
gas and the NH.sub.3 gas is, for example, 1 second to 100 seconds,
more preferably, 5 seconds to 30 seconds. When a predetermined time
elapses, the valves 412a, 413a, 422a and 412d are closed, and
supply of the HCD gas and the NH.sub.3 gas into the process chamber
201 is stopped. In addition, the valve 422d is kept open.
[0113] As described above, the HCD gas and the NH.sub.3 gas
supplied into the process chamber 201 pass over the wafer 200 to be
exhausted through the gas exhaust pipe 231. When the HCD gas passes
over the wafer 200, the HCD gas is chemisorbed to a surface of the
resist lens 10 on the wafer or a surface of a Si-containing layer
formed by adsorbing HCD molecule (or decomposed matters thereof) on
the resist lens 10, forming the Si-containing layer.
[0114] The NH.sub.3 gas accelerates formation of the Si-containing
layer by chemosorption of the HCD gas. That is, as shown in FIG.
6A, the NH.sub.3 gas, which is a catalyst, is reacted with an
OH-bond of a surface of, for example, the resist lens 10 or the
Si-containing layer, weakening a bonding force between O--H.
Hydrogen (H), a bonding force of which is weakened, is reacted with
chlorine (Cl) of the HCD gas to separate hydrogen chloride (HCl)
gas, and HCD molecules (a halide), from which Cl is lost, is
chemisorbed with the surface of the resist lens 10, etc. The
NH.sub.3 gas weakens the bonding force between O--H because N atoms
having lone electron pairs in the NH.sub.3 molecules function to
pull H. Since the NH.sub.3 gas has an acid dissociation constant
(hereinafter referred to as pKa), which is an index of a force
pulling H, of about 9.2, the force pulling H is relatively
strong.
[0115] <Exhaust Process S104b>
[0116] As described above, after a predetermined time has elapsed
to stop supply of the HCD gas and the NH.sub.3 gas, the APC valve
243 is opened to exhaust an atmosphere in the process chamber 201,
eliminating the remaining HCD gas, NH.sub.3 gas, decomposed matters
after reaction (an exhaust gas), and so on. In addition, in a state
in which the valve 422d is opened, the valve 432a is opened, and
the purge gas is supplied into the process chamber 201 while
controlling a flow rate by the mass flow controllers 431a and 421d.
At this time, the valves 432b and 422c may be further opened, and
the purge gas may be supplied through the purge gas supply pipe
430b or the inert gas supply pipe 420c. Accordingly, the effect of
eliminating the remaining gas from the inside of the process
chamber 201 can be further improved. After a predetermined time
elapses, the valves 432a and 422d are closed and the exhaust
process S104b is terminated.
[0117] <Oxidizing Source and Catalyst Supply Process
S104c>
[0118] After removing the remaining gas in the process chamber 201,
the H.sub.2O gas, which is an oxidizing source, and the NH.sub.3
gas, which is a catalyst, are supplied into the process chamber
201. That is, the valves 412c and 422c are opened, and the H.sub.2O
gas is supplied into the process chamber with the inert gas, which
is a carrier gas, while controlling flow rates by the mass flow
controllers 411c and 421c. In addition, in the same sequence as the
first processing source and catalyst supply process S104a, the
NH.sub.3 gas is supplied into the process chamber 201 with the
inert gas, which is a carrier gas.
[0119] When the H.sub.2O gas and the NH.sub.3 gas are supplied into
the process chamber 201, the pressure in the process chamber 201
is, for example, 10 Torr. In addition, for example, a ratio of a
flow rate (sccm) of the H.sub.2O gas/a flow rate (sccm) of the
NH.sub.3 gas is 0.01 to 100, more preferably, 0.05 to 10. At this
time, it is more preferable that mass percent concentrations of the
H.sub.2O gas and the NH.sub.3 gas are substantially equal to each
other. The supply time of the gases may be, for example, 1 second
to 100 seconds, more preferably, 5 seconds to 30 seconds. When a
predetermined time elapses, the valves 412c and 412d are closed,
and supply of the H.sub.2O gas and the NH.sub.3 gas into the
process chamber 201 is stopped. In addition, the valves 422c and
422d are kept open.
[0120] As described above, the H.sub.2O gas and the NH.sub.3 gas
supplied into the process chamber 201 pass over the wafer 200 to be
exhausted through the gas exhaust pipe 231. When passing over the
wafer 200, the H.sub.2O gas surface-reacts with the Si-containing
layer, etc., formed on the resist lens 10, and the Si-containing
layer, etc., is oxidized to be converted into a SiO layer. In
addition, the SiO layer is a silicon oxide layer having an
arbitrary composition ratio including SiO.sub.2.
[0121] The NH.sub.3 gas accelerates the surface reaction of the
H.sub.2O gas with the Si-containing layer. That is, as shown in
FIG. 6B, the NH.sub.3 gas, which is a catalyst, reacts with an O--H
bond included in the H.sub.2O gas to weaken the bonding force
between O--H. H, a bonding force of which is weakened, reacts with
Cl included in the Si-containing layer on the resist lens 10 to
separate hydrogen chloride (HCl) gas, and O of the H.sub.2O gas,
from which H is lost, is added to Si, from which Cl is
separated.
[0122] <Exhaust Process S104d>
[0123] After stopping supply of the H.sub.2O gas and the NH.sub.3
gas, the APC valve 243 is opened to exhaust the atmosphere in the
process chamber 201, and the remaining H.sub.2O gas, NH.sub.3 gas,
decomposed matters after reaction (exhaust gas), etc., are
eliminated. In addition, the inert gas, which is a purge gas, is
supplied into the process chamber 201 while controlling flow rates
by the mass flow controllers 421c and 421d via the valves 422c and
422d in an open state. At this time, another purge gas supply pipe
may be used. After a predetermined time elapses, the valves 422c
and 422d are closed to stop the exhaust process S104d.
[0124] <Process of Performing Predetermined Number of Times
S104e)>
[0125] The processes S104a to S104d are set as one cycle and the
cycle is performed a predetermined number of times, forming the SiO
layer on the resist lens 10 of the wafer 200 to a predetermined
film thickness, for example, 2.0 .ANG. to 10,000 .ANG.. FIG. 5
shows an example in which the cycle is performed p times. A
horizontal axis of FIG. 5 represents elapsed time, and a vertical
axis of FIG. 5 represents a gas supply timing of each gas. From the
above, the first cycle process S104a to S104e is terminated.
[0126] As described above, in each of the first processing source
and catalyst supply process S104a and the oxidizing source and
catalyst supply process S104c, since the NH.sub.3 gas is used as a
catalyst, chemisorption of the HCD gas can be accelerated even
under a low temperature, and surface reaction of the H.sub.2O gas
can also be accelerated. As described above, as the SiO layer is
formed under a low temperature, thermal denaturation of the resist
lens 20 can be suppressed and occurrence of bad resist lenses 10
can be reduced.
[0127] <Second Processing Source and Catalyst Supply Process
S105a>
[0128] In the second processing source and catalyst supply process
S105a of the second cycle process S105a to S105e, TiCl.sub.4 gas,
which is a second processing source, and NH.sub.3 gas, which is a
catalyst, are supplied into the process chamber 201.
[0129] Specifically, first, before initiating supply of the
TiCl.sub.4 gas, the TiCl.sub.4 gas is previously generated in the
evaporator 415b. That is, the valve 412b is opened, and liquid
TiCl.sub.4 is supplied into the evaporator 415b to generate the
TiCl.sub.4 gas while controlling a flow rate of the liquid mass
flow controller 411b. When the TiCl.sub.4 gas is supplied, the
valve 422b is opened, and the carrier gas is supplied into the
evaporator 415b while controlling a flow rate by the mass flow
controller 421b. In addition, the valve 413b is opened, and the
generated TiCl.sub.4 gas is supplied into the process chamber 201
with the carrier gas. Further, in a sequence similar to the first
processing source and catalyst supply process S104a, the NH.sub.3
gas is supplied into the process chamber 201 with the inert gas,
which is a carrier gas.
[0130] The pressure, supply amount and supply time of the gas,
etc., when the TiCl.sub.4 gas and the NH.sub.3 gas are supplied
into the process chamber 201 may be the same as in the first
processing source and catalyst supply process S104a. When a
predetermined time elapses, the valves 412b, 413b, 422b and 412d
are closed, and supply of the TiCl.sub.4 gas and the NH.sub.3 gas
into the process chamber 201 is stopped. In addition, the valve
422d is kept open.
[0131] Similar to the first processing source and catalyst supply
process S104a, chemisorption of the TiCl.sub.4 gas is accelerated
by the NH.sub.3 gas, and a Ti-containing layer is formed on a
surface of the SiO layer, a surface of the already formed
Ti-containing layer, etc.
[0132] <Exhaust Process S105b>
[0133] After stopping supply of the TiCl.sub.4 gas and the NH.sub.3
gas, the APC valve 243 is opened to exhaust the atmosphere in the
process chamber 201 and the remaining TiCl.sub.4 gas or NH.sub.3
gas, decomposed matters after reaction (exhaust gas), etc., are
eliminated. In addition, the valve 432 is further opened in a state
in which the valve 422d is opened, and the purge gas is supplied
into the process chamber 201 while controlling a flow rate by the
mass flow controller 431b and 421d. At this time, another purge gas
supply pipe, etc., may be used. After a predetermined time elapses,
the valves 432b and 422d are closed to stop the exhaust process
S105b.
[0134] <Oxidizing Source and Catalyst Supply Process
S105c>
[0135] In a sequence and processing conditions similar to the
oxidizing source and catalyst supply process S104c, the H.sub.2O
gas and the NH.sub.3 gas are supplied into the process chamber 201.
The Ti-containing layer, etc., is oxidized by a reaction similar to
the oxidizing source and catalyst supply process S104c to be
converted into a TiO layer. In addition, the TiO layer is a
titanium oxide layer, which is a metal oxide layer, having an
arbitrary composition ratio including TiO.sub.2.
[0136] <Exhaust Process S105d>
[0137] In a sequence similar to the exhaust process S104d, the
atmosphere in the process chamber 201 is exhausted to eliminate the
remaining H.sub.2O gas, etc. In addition, the purge gas is supplied
into the process chamber 201.
[0138] <Process S105e of Performing Predetermined Number of
Times>
[0139] The processes S105a to S105d are set as one cycle and the
cycle is performed a predetermined number of times. The TiO layer
is formed on the SiO layer of the wafer 200 to a predetermined film
thickness, for example, 2.0 .ANG. to 10,000 .ANG.. FIG. 5 shows an
example in which the cycle is performed q times. From the above,
the second cycle process S105a to S105e is terminated.
[0140] As described above, even when the TiO layer is formed using
the TiCl.sub.4 gas, the NH.sub.3 gas may be used as a catalyst in
each of the second processing source and catalyst supply process
S105a and the oxidizing source and catalyst supply process S105c,
accelerating chemisorption of the TiCl.sub.4 gas even under a low
temperature and also accelerating surface reaction of the H.sub.2O
gas. As described above, when the TiO layer is formed under a low
temperature, thermal denaturation of the resist lens 10 can be
suppressed to reduce occurrence of a bad resist lens 10.
[0141] <Process S106 Performed Predetermined Number of
Times>
[0142] In the process S106 performed a predetermined number of
times, the first cycle process S104a to S104e and the second cycle
process S105a to S105e are set as one set, and the set is performed
with a predetermined combination a predetermined number of times
(for example, p times and q times, respectively), forming the SiTiO
film 21 on the resist lens 10 of the wafer 200 to a predetermined
film thickness, for example, 50 .ANG. to 20,000 .ANG. (see FIG.
10B).
[0143] Since a refractive index of the TiO layer is 2.2, which is
relatively higher than 1.45--a refractive index of the SiO--as
described above, the SiTiO film 21 formed by depositing the SiO
layer and the TiO layer can obtain a high refractive index closer
to the resist lens 10 than in the SiO film formed on its own. In
addition, the SiTiO film 21 having a predetermined refractive index
may be formed by arbitrarily adjusting a deposition ratio of the
TiO layer with respect to the SiO layer. The deposition ratio may
be adjusted by the combination, i.e., the number of times each
cycle process is performed. For example, when the number of times
the first cycle process S104a to S104e is performed is 3 (p=3) and
the number of times of the second cycle process S105a to S105e is
performed is 2 (q=2), the SiTiO film 21 having a refractive index
of 1.55 can be obtained. In addition, when p=3 and q=1, the
refractive index becomes 1.50. The refractive index of the SiTiO
film 21 is selected within a range of more than a refractive index
of air to less than a refractive index of the resist lens 10.
[0144] In addition, in a state in which the arbitrary combination
is maintained, as the first cycle process S104a to S104e and the
second cycle process S105a to S105e are set as one set and the
number of times the set is performed is varied, the film thickness
of the SiTiO film 21 can be controlled in a state in which a
predetermined refractive index is maintained. Further, the first
cycle process S104a to S104e and the second cycle process S105a to
S105e may be performed in an arbitrary sequence, and the lower
layer oxide film forming process S104a to S106 may be initiated
from an arbitrary process or may be terminated at an arbitrary
process. For example, the lower layer oxide film forming process
S104a to S106 may be initiated from the second cycle process S105a
to S105e and may be terminated at the second cycle process S105a to
S105e.
[0145] <Upper Layer Oxide Film Forming Process S107a to
S107e>
[0146] Next, the processes S107a to S107d are set as one cycle and
the cycle is performed a predetermined number of times S107e,
forming the SiO film 20 on the SiTiO film 21 of the wafer 200 as an
upper layer oxide film (a low refractive index oxide film) (see
FIG. 10B). Each process of the processes S107a to S107d is
performed in a sequence and processing conditions similar to each
process of the processes S104a to S104d. Since these processes are
performed a predetermined number of times, the SiO film 20 is
formed on the SiTiO film 21 to a predetermined film thickness, for
example, 50 .ANG. to 10,000 .ANG.. At this time, the refractive
index of the SiO film 20 is within a range of more than the
refractive index of air to less than the refractive index of the
SiTiO film 21. FIG. 5 shows an example in which the cycle is
performed r times.
[0147] As described above, in this embodiment, the SiO film 20
having a relatively low refractive index is formed on the SiTiO
film 21 having a relatively high refractive index to gradually
reduce the refractive index in a thickness direction from the
resist lens 10 to the air. Accordingly, in comparison with the case
of forming only the SiO film 20, a difference in refractive index
between the media can be further attenuated to further suppress the
reflection.
[0148] <Temperature Reduction Process S108 and Normal Pressure
Returning Process S109>
[0149] When the SiTiO film 21 and the SiO film 20 are formed to a
desired film thickness, power supply to the heater 207 is stopped,
and the boat 217 and the wafer 200 are cooled to a predetermined
temperature. While reducing the temperature, the valves 432a, 432b,
422c and 422d are kept open, and supply of the purge gas into the
process chamber 201 from the purge gas supply source (not shown) is
continued. Accordingly, the inside of the process chamber 201 is
substituted by the purge gas, and the pressure in the process
chamber 201 returns to a normal pressure.
[0150] <Substrate Unloading Process S110>
[0151] When the wafer 200 is cooled to a predetermined temperature
and the inside of the process chamber 201 returns to a normal
pressure, in reverse sequence of the above sequence, the
film-formed wafer 200 is unloaded from the process chamber 201. In
addition, when the boat 217 is unloaded, the valves 432a, 432b,
422c and 422d are opened, and the purge gas may be continuously
supplied into the process chamber 201. Therefore, the substrate
processing apparatus in accordance with the embodiment is
terminated.
[0152] (5) Effects According to the Embodiment
[0153] According to the embodiment, the following one or more
effects are provided.
[0154] (a) According to the embodiment, the SiTiO film 21 and the
SiO film 20 are formed on the resist lens 20 formed on the wafer
200 in sequence. At this time, the refractive index of the SiTiO
film 21 is controlled within a range of more than the refractive
index of air to less than the refractive index of the resist lens
10, and the refractive index of the SiO film 20 is within a range
of more than the refractive index of air to less than the
refractive index of the SiTiO film 21.
[0155] As described above, as the refractive index can be varied
when the oxide film is formed and the refractive index is gradually
reduced in a thickness direction from the resist lens 10 to the
air, a difference in refractive index between the media can be
attenuated to suppress reflection of the resist lens 10, improving
light-collecting efficiency. FIG. 10B shows a shape in which the
refractive index is attenuated to suppress reflection (reflective
light 6a, 6b and 6c) of surfaces of the respective films.
[0156] (b) In addition, according to the embodiment, the SiO film
20 is combined with the SiTiO film 21 having a relatively high
refractive index. Accordingly, in comparison with the case in which
only the SiO film 20 having a relatively low refractive index is
formed, since light can easily enter the photo diode 30 even when
the light enters in a side direction, light collection from a wider
angle becomes possible.
[0157] In a semiconductor device according to reference example, on
which only the SiO film 20 is formed, as show in FIG. 10A, since
the refractive index of the SiO film 20 is low, light collection
from the wide angle may become difficult. That is, since refraction
of incident light 2 in the SiO film 20 is shallow (refractive light
7b), the light is deviated from the photo diode 30 as much as the
light enters in a side direction.
[0158] However, in this embodiment, since the SiTiO film 21 having
a relatively high refractive index is combined with the SiO film
20, as shown in FIG. 10B, the incident light 5 can reach the photo
diode 30 from a wider angle (refractive light 7a), improving light
collecting efficiency.
[0159] (c) In addition, according to the embodiment, the first
cycle S104a to S104e and the second cycle S105a to S105e are set as
one set and the set is performed with a predetermined combination a
predetermined number of times (S106), forming the SiTiO film 21.
Accordingly, a deposition ratio of the TiO layer with respect to
the SiO layer can be adjusted to obtain the SiTiO film 21 having a
predetermined refractive ratio.
[0160] (d) Further, according to the embodiment, since the first
cycle S104a to S104e and the second cycle S105a to S105e are set as
one set and the number of times the set is performed is varied, the
film thickness of the SiTiO film 21 can be controlled. At this
time, when the predetermined combination is maintained, the
refractive index of the SiTiO film 21 can be maintained at a
predetermined value.
[0161] (e) Furthermore, according to the embodiment, the SiTiO film
21 and the SiO film 20 are formed using the NH.sub.3 gas, which is
a catalyst. In addition, at this time, the heating temperature of
the wafer 200 is 200.degree. C. or less, more preferably,
150.degree. C. or less. Using the catalyst, even under the low
temperature, chemisorption of the HCD gas and the TiCl.sub.4 gas
can be accelerated and surface reaction of the H.sub.2O gas can
also be accelerated. That is, since only the oxide film such as the
SiTiO film 21 and the SiO film 20 are mainly formed, the film can
be formed using the catalyst under the low temperature.
Accordingly, thermal denaturation of the resist lens 10 can be
suppressed and occurrence of a bad resist lens 10 can be reduced,
improving properties thereof
[0162] (f) Further, according to the embodiment, the SiTiO film 21
and the SiO film 20 are continuously formed in the same process
chamber 201. Accordingly, efforts such as conveyance of the wafer
200 to another process furnace in the middle of the process can be
omitted. In addition, since no wafer 200 is exposed to the air in
the middle of the process, an oxide film of a better quality can be
formed.
[0163] Furthermore, in this embodiment, while the example in which
the NH.sub.3 gas is used as a catalyst is described, the catalyst
is not limited to ammonia but may be another material such as
pyridine.
Second Embodiment
[0164] Hereinafter, a substrate processing process in accordance
with a second embodiment will be described. Unlike the embodiment
in which the refractive index is gradually varied in two steps, in
the substrate processing process in accordance with the embodiment,
a SiTiO film is formed such that a refractive index is gradually
reduced in a thickness direction from a surface thereof in contact
with a resist lens 10 to an opposite surface in contact with air,
not forming a SiO film 20. In addition, in this embodiment, an
example in which pyridine (C.sub.5H.sub.5N) gas is used as a
catalyst will be described.
[0165] (1) Substrate Processing Process
[0166] Hereinafter, the substrate processing process in accordance
with the embodiment will be described in detail with reference to
FIGS. 7 and 8 in detail. The substrate processing process in
accordance with the embodiment is also performed using the process
furnace 202 of FIGS. 2 and 3, and operation of the respective parts
is controlled by the controller 280. However, since the pyridine is
in a liquid phase at room temperature, an apparatus of the
embodiment includes a catalyst supply pipe 410d, an evaporator (not
shown), and so on.
[0167] <Substrate Loading Process 5201 to Temperature Increase
Process S203>
[0168] A substrate loading process 5201, a pressure reduction
process 5202 and a temperature increase process S203 shown in FIG.
7 are performed in the same sequence as the corresponding processes
S101 to S103 of the above embodiment.
[0169] <Deposition Oxide Film Forming Process S204a to
S206>
[0170] Next, processes S204a to S206 of FIG. 7 are performed to
form a SiTiO film, which is a deposition oxide film, on a resist
lens 10 formed on the wafer 200. In the deposition oxide film
forming process S204a to S206, a first cycle process S204a to S204e
and a second cycle process S205a to S205e are set as one set and
the set is performed with a predetermined combination a
predetermined number of times (S206), forming the SiTiO film.
[0171] <First Cycle Process S204a to S204e>
[0172] The first cycle process S204a to S204e is performed in a
sequence and processing conditions similar to the first cycle
process S104a to S104e in accordance with the embodiment. At this
time, pyridine gas is used as a catalyst. Similar to the NH.sub.3
gas, the pyridine gas functions to pull H (pKa=5.7) because an N
atom of a pyridine molecule has a lone electron pair. Accordingly,
as shown in FIGS. 9A and 9B, a bonding force of a surface of the
resist lens 10 or the Si-containing layer or an O--H bond in the
H.sub.2O gas is weakened, and thus, chemisorption of the HCD gas is
accelerated and surface reaction of the H.sub.2O gas is also
accelerated.
[0173] Accordingly, the SiO layer is formed on the resist lens 10
of the wafer 200 to a predetermined film thickness, for example,
2.0 .ANG. to 1,000 .ANG.. FIG. 8 shows an example in which the
cycle is performed m times.
[0174] <Second Cycle Process S205a to S205e>
[0175] The second cycle process S205a to S205e is performed in a
sequence and processing conditions similar to the second cycle
process S105a to S105e in accordance with the embodiment. The
pyridine gas is used as a catalyst. Accordingly, the TiO layer is
formed on the SiO layer of the wafer 200 to a predetermined film
thickness, for example, 2.0 .ANG. to 1,000 .ANG.. FIG. 8 shows an
example in which the cycle is performed n times.
[0176] <Process S206 of Performing Predetermined Number of
Times>
[0177] In the process S206 performed a predetermined number of
times, the first cycle process S204a to S204e and the second cycle
process S205a to S205e are set as one set and the set is performed
with a predetermined combination (for example, m times and n times,
respectively) a predetermined number of times, forming the SiTiO
film on the resist lens 10 of the wafer 200 to a predetermined film
thickness, for example, 2.0 .ANG. to 2,000 .ANG..
[0178] Here, in this embodiment, as the deposition ratio of the TiO
layer with respect to the SiO layer is gradually reduced, the SiTiO
film is formed such that the refractive index is gradually reduced
in a thickness direction from a surface thereof in contact with the
resist lens 10 to an opposite surface in contact with air.
Specifically, as the number of times the second cycle process S205a
to S205e is performed with respect to the number of times the first
cycle process S204a to S204e is performed, i.e., a value of n with
respect to a value of m, is gradually reduced, the first cycle
process S204a to S204e and the second cycle process S205a to S205e
are set as one set and the set is performed a predetermined number
of times. At this time, the refractive index of the SiTiO film is
varied within a range of a refractive index of air to less than a
refractive index of the resist lens 10.
[0179] In addition, a performing sequence of the first cycle
process S204a to S204e and the second cycle process S205a to S205e
is arbitrary. For example, the deposition oxide film forming
process S204a to S206 may be initiated from the second cycle
process S205a to S205e and may be terminated at the first cycle
process S204a to S204e.
[0180] As described above, in this embodiment, the refractive index
may be gradually reduced in a thickness direction from the resist
lens 10 to the air and a difference in refractive index between the
media may be attenuated, suppressing reflection of the resist lens
10.
[0181] <Temperature Reduction Process S208 to Substrate
Unloading Process S210>
[0182] A temperature reduction process S208, a normal pressure
returning process S209 and a substrate unloading process S210 are
performed in a sequence similar to the corresponding processes S108
to S110 of the embodiment. From the above, the substrate processing
process in accordance with the embodiment is terminated.
[0183] (2) Effects According to the Embodiment
[0184] The embodiment has the same effects as the above
embodiment.
[0185] (a) In addition, according to the embodiment, the SiTiO film
is formed such that the refractive index is gradually reduced in
the thickness direction from the surface in contact with the resist
lens 10 to the opposite surface in contact with the air.
Accordingly, the difference in refractive index between the media
can be further attenuated to suppress reflection of the resist lens
10.
[0186] (b) Further, according to the embodiment, the SiTiO film is
formed using the pyridine, which is a catalyst. Accordingly,
particles are reduced.
[0187] As described above, when the NH.sub.3 gas is used as a
catalyst, as the NH.sub.3 gas and the HCD gas are simultaneously
supplied, a reaction between the NH.sub.3 gas and the HCD gas
partially occurs so that NH.sub.4Cl is generated as a byproduct,
generating particles (see FIG. 6A).
[0188] However, in this embodiment, since the pyridine (pKa) gas
having a smaller acid dissociation constant pKa than the NH.sub.3
gas and low reactivity with a group 17 element such as Cl is used
as a catalyst, generation of byproducts can be suppressed and
particles can be reduced.
Third Embodiment
[0189] Hereinafter, a substrate processing process in accordance
with a third embodiment of the present invention will be described
below. The substrate processing process in accordance with the
embodiment is distinguished from the above embodiment in that
plasma is used instead of the catalyst to activate the H.sub.2O
gas, which is an oxidizing source, improving reactivity.
[0190] In the substrate processing process in accordance with the
embodiment, in addition to the configuration shown in FIGS. 2 and
3, a process furnace having a mechanism configured to generate
plasma is used. The mechanism mainly includes a buffer chamber,
which is a gas distribution space, installed at an inner wall of
the reaction tube 203, a pair of rod-shaped electrodes installed in
the buffer chamber, and a radio frequency power source connected to
the rod-shaped electrodes via an adapter, none of which are shown.
The H.sub.2O gas, which is an oxidizing source, is supplied into
the buffer chamber through a third nozzle 400c disposed in the
buffer chamber and connected to a downstream end of the oxidizing
source supply pipe 410c, and a high frequency power is applied to
the rod-shaped electrodes from the high frequency power source via
the adapter, so that the H.sub.2O gas in a plasma state is supplied
into the process chamber 201.
[0191] The substrate processing process in accordance with the
embodiment is performed using the process furnace including the
configuration as follows. That is, in the process corresponding to
the first processing source and catalyst supply process S104a,
S107a and S204a or the second processing source and catalyst supply
process S105a and S205a in accordance with the embodiment,
chemisorption of each source is accelerated by the catalyst similar
to the above embodiment, without converting the first processing
source or the second material into a plasma state. In addition, in
the oxidizing supply process performed in response to each of the
source and catalyst supply processes, the H.sub.2O gas in a plasma
state is supplied into the process chamber 201 to accelerate
surface reaction by the H.sub.2O gas, without supplying the
catalyst.
[0192] As described above, in this embodiment, the H.sub.2O gas in
a plasma state may be supplied into the process chamber 201 to
accelerate surface reaction by the H.sub.2O gas under a low
temperature, even when the catalyst is not used.
Other Embodiments
[0193] Hereinabove, although embodiments of the present invention
have been specifically described, the present invention is not
limited thereto but various modifications may be made without
departing from the teaching of the present invention.
[0194] For example, in the embodiments, while the photo resist is
used as a lens material, in addition to a photosensitive resin such
as the photo resist, a resin having plasticity or curability with
respect to heat or light may be used, specifically, acryls,
phenols, styrenes, etc. A refractive index of the acryls is 1.5.
These resins may be transparent resins through which light having a
predetermined wavelength such as visible light passes. In addition,
for example, an inorganic material such as glass or quartz
(SiO.sub.2) may be used as a lens material.
[0195] Further, in the embodiment, while supply of the oxidizing
source and supply of the first processing source or the second
processing source are alternately performed, when a complex oxide
film is formed, the oxidizing source may be supplied at
predetermined intervals during alternate supplies of the first
processing source and the second processing source a predetermined
number of times.
[0196] Furthermore, in addition to the HCD gas, silicon-based
chloride gases such as dichlorosilane (DCS: SiH.sub.2Cl.sub.2) gas,
trichlorosilane (SiHCl.sub.3) gas, tetrachlorosilane (SiCl.sub.4)
gas, or octachlorotrisilane (Si.sub.3Cl.sub.8) gas, fluoride gases,
boromide gases, and iodide gases may be used as the Si-containing
gas, which is a first element. In addition, the first element may
be an element other than Si, or may include a plurality of
elements.
[0197] Further, in addition to TiCl.sub.4 gas, various
titanium-based chloride, fluoride, boromide and iodide gases may be
used as a Ti-containing gas, which is a second element.
Furthermore, in addition to Ti, hafnium (Hf), zirconium (Zr), etc.,
may be used as the second element as long as the predetermined
refractive index can be obtained when a complex oxide film is
formed in combination with the first element such as Si. For
example, refractive indices of a HfO layer and a ZrO layer are 2.3
and 2.2, respectively. The second element may include a plurality
of elements.
[0198] In addition, in addition to the H.sub.2O gas, hydrogen
peroxide (H.sub.2O.sub.2) gas, a mixed gas of hydrogen (H.sub.2)
gas and ozone (O.sub.3) gas, mixed gas plasma of hydrogen (H.sub.2)
gas and oxygen (O.sub.2) gas, etc., may be used as an O-containing
gas, which is an oxidizing source. When the catalyst is used as in
the embodiment, the gases may be used as the oxidizing source as
long as the gases containing elements with different
electro-negativities among molecules have electrical deviation. The
O.sub.2 gas or O.sub.3 gas with no electrical deviation may be used
when the plasma is used as in the third embodiment.
[0199] Further, in addition to the NH.sub.3 gas or the pyridine
gas, a gas having a relatively high pKa such as trimethylamine
[N(CH.sub.3).sub.3, pKa=9.8] gas, methylamine [H.sub.2N(CH.sub.3),
pKa=10.6] gas or triethylamine [N(C.sub.2H.sub.5).sub.3, pKa=10.7]
gas, or a gas having a relatively low pKa similar to the pyridine
gas, such as heterocycle to which N is bonded, for example,
aminopyridine (C.sub.5H.sub.4N--NH.sub.2, pKa=6.9), picoline
[C.sub.5H.sub.4N(CH.sub.3), pKa=6.1], piperazine
[C.sub.4H.sub.10N.sub.2, pKa=5.7], lutidine
[C.sub.5H.sub.3N(CH.sub.3).sub.2, pKa=7.0], etc., may be used as
the catalyst.
[0200] <Preferred Aspects of the Invention>
[0201] Hereinafter, preferred aspects of the present invention will
be additionally stated.
[0202] An aspect of the present invention provides a method of
manufacturing a semiconductor device, including:
[0203] (a) forming a lower layer oxide film on a lens formed on a
substrate using a first processing source containing a first
element, a second processing source containing a second element, an
oxidizing source and a catalyst, the lower layer oxide film having
a refractive index greater than that of air and less than that of
the lens; and
[0204] (b) forming an upper layer oxide film on the lower layer
oxide film using the first processing source, the oxidizing source
and the catalyst, the upper layer oxide film having a refractive
index greater than that of the air and less than that of the lower
layer oxide film.
[0205] Preferably, at least one of the process (a) and the process
(b) may include heating the substrate to a temperature ranging from
room temperature to 200.degree. C.
[0206] More preferably, at least one of the process (a) and the
process (b) may include heating the substrate to a temperature
ranging from room temperature to 150.degree. C.
[0207] Preferably, the first element may contain at least silicon,
and the second element may contain one of at least titanium,
hafnium and zirconium.
[0208] Preferably, the lens may include a transparent resin as a
major material.
[0209] Preferably, the process (a) may include:
[0210] (a-1) performing one or more times a first cycle including
supplying the first processing source and the catalyst into a
process chamber accommodating the substrate; exhausting the process
chamber; supplying the oxidizing source and the catalyst into the
process chamber; and exhausting the process chamber;
[0211] (a-2) performing one or more times a second cycle including
supplying the second processing source and the catalyst into the
process chamber accommodating the substrate; exhausting the process
chamber; supplying the oxidizing source and the catalyst into the
process chamber; and exhausting the process chamber; and
[0212] (a-3) performing a combination of the steps (a-1) and (a-2),
and
[0213] the process (b) may include: performing one or more times a
third cycle including supplying the first processing source and the
catalyst into the process chamber accommodating the substrate;
exhausting the process chamber; supplying the oxidizing source and
the catalyst into the process chamber; and exhausting the process
chamber.
[0214] Another aspect of the present invention provides a
semiconductor device including: a lens; a lower layer oxide film
disposed on the lens, the lower layer oxide film having a
refractive index greater than that of air and less than that of the
lens and being formed using a first processing source containing a
first element, a second processing source containing a second
element, an oxidizing source and a catalyst; and an upper layer
oxide film disposed on the lower layer oxide film, the upper layer
oxide film having a refractive index greater than that of the air
and less than that of the lower layer oxide film and being formed
using the first processing source, the oxidizing source and the
catalyst.
[0215] Still another aspect of the present invention provides a
substrate processing apparatus including: a process chamber
configured to accommodate a substrate, the substrate having a lens
disposed thereon;
[0216] a heating part configured to heat the substrate;
[0217] a first processing source supply part configured to supply a
first processing source containing a first element into the process
chamber;
[0218] a second processing source supply part configured to supply
a second processing source containing a second element into the
process chamber;
[0219] an oxidizing source supply part configured to supply an
oxidizing source into the process chamber;
[0220] a catalyst supply part configured to supply a catalyst into
the process chamber;
[0221] an exhaust part configured to exhaust an atmosphere in the
process chamber; and
[0222] a control unit configured to control the heating part, the
first processing source supply part, the second processing source
supply part, the oxidizing source supply part, the catalyst supply
part and the exhaust part to form a lower layer oxide film on the
lens using the first processing source, the second processing
source, the oxidizing source and the catalyst, the lower layer
oxide film having a refractive index greater than that of air and
less than that of the lens, and to form an upper layer oxide film
on the lower layer oxide film using the first processing source,
the oxidizing source and the catalyst, the upper layer oxide film
having a refractive index greater than that of the air and less
than that of the lower layer oxide film.
[0223] Yet another aspect of the present invention provides a
method of manufacturing a semiconductor device, including: forming
a deposition oxide layer on a lens formed on a substrate using a
first processing source containing a first element, a second
processing source containing a second element, an oxidizing source
and a catalyst, the deposition oxide layer having a refractive
index equal to or greater than that of air and equal to or less
than of the lens,
[0224] wherein, in the forming the deposition oxide layer, the
deposition oxide layer is formed such that the refractive index in
the deposition oxide layer is gradually reduced from a surface
thereof in contact with the lens to a surface opposite to the lens
and in contact with the air.
[0225] Preferably, the forming the deposition oxide layer may
include: (a) performing m times a first cycle including supplying
the first processing source and the catalyst into the process
chamber accommodating the substrate, exhausting the atmosphere in
the process chamber, supplying the oxidizing source and the
catalyst into the process chamber, and exhausting the atmosphere in
the process chamber; (b) performing n times a second cycle
including supplying the second processing source and the catalyst
into the process chamber accommodating the substrate, exhausting
the atmosphere in the process chamber, supplying the oxidizing
source and the catalyst into the process chamber, and exhausting
the atmosphere in the process chamber; and (c) performing the steps
(a) and (b) with a combination a predetermined number of times,
and
[0226] the deposition oxide layer is formed such that the
refractive index in the deposition oxide layer is gradually reduced
from a surface thereof in contact with the lens to a surface
opposite to the lens and in contact with the air by gradually
reducing a value of n with respect to a value of m.
[0227] Yet another embodiment of the present invention provides a
semiconductor device including: a lens; and a deposition oxide film
formed on the lens using a first processing source containing a
first element, a second processing source containing a second
element, an oxidizing source and a catalyst, wherein the deposition
oxide film has a refractive index equal to or greater than that of
air and equal to or less than that of the lens, and is configured
such that the refractive index in the deposition oxide film is
gradually reduced from a surface thereof in contact with the lens
to a surface opposite to the lens and in contact with the air.
[0228] Yet another aspect of the present invention provides a
substrate processing apparatus including: a process chamber
configured to accommodate a substrate, the substrate having a lens
disposed thereon; a heating part configured to heat the substrate;
a first processing source supply part configured to supply a first
processing source containing a first element into the process
chamber; a second processing source supply part configured to
supply a second processing source containing a second element into
the process chamber; an oxidizing source supply part configured to
supply an oxidizing source into the process chamber; a catalyst
supply part configured to supply a catalyst into the process
chamber; an exhaust part configured to exhaust an atmosphere in the
process chamber; and a control unit configured to control the
heating part, the first processing source supply part, the second
processing source supply part, the oxidizing source supply part,
the catalyst supply part, and the exhaust part to form a deposition
oxide film having a refractive index equal to or greater than that
of air and equal to or less than that of the lens on the lens using
the first processing source, the second processing source, the
oxidizing source and the catalyst, wherein the control unit
controls the heating part, the first processing source supply part,
the second processing source supply part, the oxidizing source
supply part, the catalyst supply part, and the exhaust part such
that the refractive index in the deposition oxide film is gradually
reduced from a surface thereof in contact with the lens to a
surface opposite to the lens and in contact with the air.
[0229] Yet another aspect of the present invention provides a
method of manufacturing a semiconductor device, including: forming
a lower layer oxide film on a lens formed on a substrate using a
first processing source containing a first element, a second
processing source containing a second element and an oxidizing
source in a plasma state, the a lower layer oxide film having a
refractive index greater than that of air and less than of a lens;
and
[0230] forming an upper layer oxide film on the lower layer oxide
film using the first processing source and the oxidizing source in
a plasma state, the upper layer oxide film having a refractive
index greater than that of the air and less than that of the
lens.
[0231] Yet another aspect of the present invention provides a
method of manufacturing a semiconductor device, including: forming
a deposition oxide film on a lens formed on a substrate using a
first processing source containing a first element, a second
processing source containing a second element, and an oxidizing
source in a plasma state, the deposition oxide film having a
refractive index equal to or greater than that of air and equal to
or less than of the lens,
[0232] wherein, in the forming the deposition oxide film, the
deposition oxide film is formed such that the refractive index in
the deposition oxide film is gradually reduced from a surface
thereof in contact with the lens to a surface opposite to the lens
and in contact with the air.
[0233] Yet another aspect of the present invention provides a
semiconductor device including: a lens; and an oxide film disposed
on the lens, the oxide film having a refractive index equal to or
greater than that of air and equal to or less than that of the
lens,
[0234] wherein the oxide film is formed by depositing a silicon
oxide layer; and a metal oxide layer containing one of at least
titanium, hafnium and zirconium and having a refractive index
greater than that of the silicon oxide layer.
[0235] Preferably, the oxide film may be configured such that the
refractive index of the oxide film can be controlled by controlling
a deposition ratio between the silicon oxide layer and the metal
oxide layer.
[0236] Preferably, the oxide film may be configured such that the
refractive index of the oxide film is gradually increased or
decreased by gradually increasing or decreasing a deposition ratio
of the metal oxide layer with respect to the silicon oxide
layer.
[0237] Preferably, the oxide film may be formed at a temperature of
100.degree. C. or less.
[0238] Preferably, the lens may be a lens for a CMOS image sensor
installed over a light receiving element.
* * * * *