U.S. patent application number 09/883581 was filed with the patent office on 2002-01-03 for method of forming an al2o3 film in a semiconductor device.
Invention is credited to Jang, Hyuk Kyoo, Lim, Chan.
Application Number | 20020001969 09/883581 |
Document ID | / |
Family ID | 19674490 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020001969 |
Kind Code |
A1 |
Jang, Hyuk Kyoo ; et
al. |
January 3, 2002 |
Method of forming an Al2O3 film in a semiconductor device
Abstract
A method is disclosed for forming an aluminum oxide film on a
semiconductor device. In a process of depositing an aluminum oxide
film by atomic layer deposition method using TMA (trimethyl
aluminum; Al(CH.sub.3).sub.3) as an aluminum source and H.sub.2O as
an oxygen reaction gas, the disclosed method supplies a NH.sub.3
reaction gas at the same time when an aluminum source is supplied.
Therefore, it can increase the growth rate of an aluminum oxide
film and can also improve the characteristic of preventing
penetration of hydrogen into an underlying layer or a semiconductor
substrate. Thus, the disclosed method can prevent degradation in a
charge storage characteristic in a capacitor and lower in an
electrical characteristic of various elements, thus improving an
overall characteristic of a semiconductor device.
Inventors: |
Jang, Hyuk Kyoo;
(Kyungki-do, KR) ; Lim, Chan; (Kyungki-do,
KR) |
Correspondence
Address: |
MARSHALL, O'TOOLE, GERSTEIN, MURRAY & BORUN
6300 SEARS TOWER
233 SOUTH WACKER DRIVE
CHICAGO
IL
60606-6402
US
|
Family ID: |
19674490 |
Appl. No.: |
09/883581 |
Filed: |
June 18, 2001 |
Current U.S.
Class: |
438/758 ;
257/E21.28; 427/255.32 |
Current CPC
Class: |
C23C 16/45534 20130101;
H01L 21/0228 20130101; H01L 21/31616 20130101; C23C 16/403
20130101; H01L 21/02178 20130101 |
Class at
Publication: |
438/758 ;
427/255.32 |
International
Class: |
C23C 016/06; H01L
021/31; H01L 021/469 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2000 |
KR |
2000-36050 |
Claims
What is claimed:
1. A method of forming an aluminum oxide film on a substrate,
comprising: a first step of simultaneously supplying an aluminum
source and an activation gas via individual lines into a reactor in
which a substrate is mounted; a second step of removing un-reacted
aluminum source gas and reaction by-products from said reactor; a
third step of supplying oxygen reaction gas into said reactor; a
fourth step of removing un-reacted oxygen gas from said reactor;
and a fifth step of repeatedly performing said first step through
said fourth step to form an aluminum oxide film on the
substrate.
2. The method of claim 1, wherein the reactor is maintained at the
temperature ranging from about 200.degree. C. to about 450.degree.
C.
3. The method of claim 1, wherein the aluminum source is supplied
into said reactor using TMA or MTMA for a time period ranging from
about 0.1 second to about 3 seconds.
4. The method of claim 1, wherein the activation gas is supplied
into said reactor using NH.sub.3 gas at a flow rate ranging from
about 10 sccm to about 500 sccm for a time period ranging from
about 0.1 second to about 3 seconds.
5. The method of claim 1, wherein the second step or the fourth
step purges said reactor by supplying N.sub.2 gas for a time period
ranging from about 0.1 second to about 3 seconds.
6. The method of claim 1, wherein the oxygen reaction gas is
supplied in to the reactor using H.sub.2O vapor for a time period
ranging from about 0.1 second to about 3 seconds.
7. The method of claim 1, wherein the NH.sub.3 reaction gas is
supplied in the second step or the fourth step instead of supplying
in the first step.
8. A method of forming an aluminum oxide film on a substrate,
comprising: a first step of supplying an aluminum source into a
reactor in which a substrate is mounted; a second step of removing
un-reacted aluminum source and reaction by-products from said
reactor; a third step of supplying oxygen reaction gas and an
activation gas into said reactor; a fourth step of removing
un-reacted oxygen gas from said reactor; and a fifth step of
repeatedly performing said first step through said fourth step to
form the aluminum oxide film on the substrate.
9. The method of claim 8, wherein the reactor is maintained at the
temperature ranging from about 200.degree. C. to about 450.degree.
C.
10. The method of manufacturing an aluminum oxide film in a
semiconductor device according to claim 8, wherein the aluminum
source is supplied into said reactor using TMA or MTMA for a time
period ranging from about 0.1 second to about 3 seconds.
11. The method of claim 8, wherein the activation gas is supplied
into said reactor using NH.sub.3 gas at the flow rate ranging from
about 10 sccm to about 500 sccm for a time period ranging from
about 0.1 second to about 3 seconds.
12. The method of claim 8, wherein the second step or the fourth
step purges said reactor by supplying N.sub.2 gas for a time period
ranging from about 0.1 second to about 3 seconds.
13. The method of claim 8, wherein the oxygen reaction gas is
supplied in to the reactor using H.sub.2O vapor for a time period
ranging from about 0.1 second to about 3 seconds.
14. The method of claim 8, wherein the NH.sub.3 reaction gas is
supplied in the second step or the fourth step instead of supplying
in the third step.
15. A semiconductor device comprising a substrate with an aluminum
oxide film formed thereon and made in accordance with the method of
claim 1.
16. A semiconductor device comprising a substrate with an aluminum
oxide film formed thereon and made in accordance with the method of
claim 8.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to a method of manufacturing
an aluminum oxide film in a semiconductor device. More
particularly, the invention relates to a method of manufacturing an
aluminum oxide film in a semiconductor device, which can increase
the growth rate of an aluminum oxide layer and can also improve
prevention of penetration of hydrogen into an underlying layer or
an aluminum oxide (Al.sub.2O.sub.3) film.
[0003] 2. Description of the Prior Art
[0004] A process of forming an aluminum oxide film by atomic layer
deposition method includes sequentially exposing an aluminum source
gas and an oxygen gas to a substrate, while a substrate is
maintained at a constant temperature, i.e., from 200.degree. C. to
about 450.degree. C. TMA is used as a conventional aluminum source
gases and H.sub.2O is used as a reactive gas.
[0005] A method of manufacturing an aluminum oxide film in a
conventional semiconductor device will be below explained by
reference to FIG. 1.
[0006] Referring now to FIG. 1, a process of forming an aluminum
oxide (Al.sub.2O.sub.3) film includes a supply step of an aluminum
source (A1), a first purge step (B1), a supply step of oxygen
reactive gas (C1) and a second purge step (D1). One cycle consists
of the four steps (A1, B1, C1 and D1). First, in order to form an
aluminum oxide (Al.sub.2O.sub.3) film using an atomic layer
deposition method, a semiconductor substrate is mounted into the
reactor in which an exhaust pump is equipped and is maintained at
the temperature range of 200.degree. C. to about 450.degree. C.
[0007] In the supply step of an aluminum source (A1), TMA, being an
aluminum source, is supplied into the reactor for 0.1 second to 3
seconds, so that aluminum (Al) can be adhered to the surface of the
semiconductor substrate.
[0008] In the first purge step (B1), in order to remove un-reacted
aluminum source gas and reaction by-products, a N.sub.2 gas is
implanted for 0.1 second to 3 seconds or is vacuum-purged to
exhaust via the exhaust pump.
[0009] In the supply step of oxygen gas (C1), oxygen reaction gas
is supplied in the reactor for 0.1 second to 3 seconds, so that
oxygen (O) can be adhered to the surface of the semiconductor
substrate.
[0010] In the second purge step (D1), in order to remove un-reacted
oxygen reaction gas and reaction by-products, a N.sub.2 gas is
implanted for 0.1 second to 3 seconds or is vacuum-purged to
exhaust via the exhaust pump.
[0011] In order to form an aluminum oxide film to a desired
thickness, the four steps forming one cycle are repeatedly
performed until a desired thickness is attained.
[0012] Because the deposition rate is slow in view of atomic layer
deposition method, when being applied to a mass production process,
the method described in FIG. 1 is disadvantageous in terms of cost
and further a conventional aluminum oxide film is not provided to
prevent any diffusion of hydrogen atoms.
SUMMARY OF THE DISCLOSURE
[0013] A method of manufacturing an aluminum oxide film in a
semiconductor device is disclosed which can increase the growth
rate of an aluminum oxide film and which can improve the
characteristics thereof by prohibiting penetration of hydrogen. By
supplying a NH.sub.3 reaction gas simultaneously with an aluminum
source gas in a supply step of an aluminum source, the disclosed
method prevents any degradation of electrical characteristics of
the layer overlying an aluminum oxide film and improves the
electrical characteristics of the semiconductor device.
[0014] One disclosed method of manufacturing an aluminum oxide film
in a semiconductor device is characterized in that it comprises a
first step of simultaneously supplying an aluminum source gas and
an activation gas into a reactor via individual lines in which a
substrate is mounted; a second step of removing un-reacted aluminum
source and reaction by-products from said reactor; a third step of
supplying oxygen reaction gas into the reactor; a fourth step of
removing un-reacted oxygen gas from the reactor; and a fifth step
of repeatedly performing the first step through the fourth step
constituting one cycle for depositing an aluminum oxide film to
thus form the aluminum oxide film.
[0015] In the above step, the reactor is maintained at the
temperature ranging from about 200.degree. C. to about 450.degree.
C.
[0016] The aluminum source is supplied into the reactor using TMA
or MTMA for a time period ranging from about 0.1 second to about 3
seconds.
[0017] The activation gas is supplied into the reactor using
NH.sub.3 gas at a flow rate ranging from about 10 sccm to about 500
sccm for a time period ranging from about 0.1 second to about 3
seconds.
[0018] The second step or the fourth step purges the reactor by
supplying N.sub.2 gas for a time period ranging from about 0.1
second to about 3 seconds.
[0019] The oxygen reaction gas is supplied in to the reactor using
H.sub.2O vapor for a time period ranging from about 0.1 second to
about 3 seconds.
[0020] The aluminum oxide film can be formed by supplying the
NH.sub.3 reaction gas in the second step or the fourth step instead
of supplying in the first step.
[0021] Another method of manufacturing an aluminum oxide film in a
semiconductor device is characterized in that it comprises a first
step of supplying an aluminum source into a reactor in which a
substrate is mounted; a second step of removing un-reacted aluminum
source and reaction by-products from the reactor; a third step of
supplying oxygen reaction gas and an activation gas into the
reactor; a fourth step of removing un-reacted oxygen gas from the
reactor; and a fifth step of repeatedly performing the first step
through the fourth step constituting one cycle for depositing an
aluminum oxide film to thus form the aluminum oxide film.
[0022] The reactor is maintained at the temperature ranging from
about 200.degree. C. to about 450.degree. C.
[0023] The aluminum source is supplied into the reactor using TMA
or MTMA for a time period ranging from about 0.1 second to about 3
seconds.
[0024] The activation gas is supplied into the reactor using
NH.sub.3 gas at a flow rate ranging from about 10 sccm to about 500
sccm for a time period ranging from about 0.1 second to about 3
seconds.
[0025] The second step or the fourth step purges the reactor by
supplying N.sub.2 gas for a time period ranging from about 0.1
second to about 3 seconds.
[0026] The oxygen reaction gas is supplied in to the reactor using
H.sub.2O vapor for a time period ranging from about 0.1 second to
about 3 seconds.
[0027] The NH.sub.3 reaction gas is supplied in the second step or
the fourth step instead of supplying NH.sub.3 in the third
step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The aforementioned aspects and other features of the
disclosed method will be explained in the following description,
taken in conjunction with the accompanying drawings, wherein:
[0029] FIG. 1 is a process diagram for explaining a method of
manufacturing an aluminum oxide film in a conventional
semiconductor device;
[0030] FIG. 2 is a process diagram for explaining a disclosed
method of manufacturing an aluminum oxide film in a semiconductor
device;
[0031] FIG. 3 illustrates, graphically, a comparison of the growth
rate depending on the type of gas and an exposure time when an
aluminum oxide film is grown; and
[0032] FIG. 4 illustrates, graphically, a comparison of the
penetration ratio of hydrogen depending on the type of gas to form
an aluminum oxide film.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0033] Various aspects of the disclosed method will be described in
detail by way of a preferred embodiment with reference to
accompanying drawings.
[0034] FIG. 2 is a process recipe for explaining a method of
manufacturing an aluminum oxide film in a semiconductor device.
[0035] Referring now to FIG. 2, a process of forming an aluminum
oxide (Al.sub.2O.sub.3) film includes a supply step of an aluminum
source (A2), a first purge step (B2), a supply step of oxygen
reactive gas (C2) and a second purge step (D2), wherein one cycle
comprises the four steps (A2, B2, C2 and D2). First, in order to
form an aluminum oxide (Al.sub.20.sub.3) film using an atomic layer
deposition method, a semiconductor substrate is mounted into the
reactor in which an exhaust pump is equipped and is maintained at
the temperature ranging from about 200.degree. C. to about
450.degree. C.
[0036] In the supply step of an aluminum source (A2), TMA and
NH.sub.3, being aluminum sources, are simultaneously supplied into
the reactor for a time period ranging from about 0.1 second to
about 3 seconds, so that aluminum (Al) can be adhered to the
surface of the semiconductor substrate. The NH.sub.3 reaction gas
is supplied at the flow rate ranging from about 10 sccm to about
100 sccm and, if necessary, may be supplied at the flow rate
ranging from about 10 sccm to about 100 sccm. As the NH.sub.3
reaction gas is supplied simultaneously with the aluminum source
gas, they may react within the supply line. In order to prevent
this reaction, it is recommended that the NH.sub.3 reaction gas and
the aluminum source gas be supplied via different supply lines.
[0037] In the first purge step (B2), in order to remove un-reacted
aluminum source gas and reaction by-products, a N.sub.2 gas is
implanted for a time period ranging from about 0.1 second to about
3 seconds or is vacuum-purged to exhaust via the exhaust pump.
[0038] In the supply step of oxygen gas (C2), oxygen reaction gas
is supplied in the reactor for a time period ranging from about 0.1
second to about 3 seconds, so that oxygen (O) can be adhered to the
surface of the semiconductor substrate.
[0039] In the second purge step (D2), in order to remove un-reacted
oxygen reaction gas and reaction by-products, a N.sub.2 gas is
implanted for a time period ranging from about 0.1 second to about
3 seconds or is vacuum-purged to exhaust via the exhaust pump.
[0040] In order to form an aluminum oxide film to a desired
thickness, the four steps (A2, B2, C3 and D2) forming one cycle are
repeatedly performed until a desired thickness is attained.
[0041] FIG. 3 is a characteristic graph shown to compare the growth
rate depending on the type of gas and an exposure time when an
aluminum oxide film is grown.
[0042] In the drawing, a reference numeral G1 indicates a growth
rate characteristic curve of a conventional aluminum oxide film,
which shows that the growth rate of the case that only TMA, being
an aluminum source, is supplied to form an aluminum oxide film.
[0043] On the other hand, a reference numeral G2 indicates a growth
rate characteristic curve of an aluminum oxide film according to
the disclosed method, which shows that the growth rate of the case
that only TMA and NH3 reaction gas at a flow rate of 30 sccm, being
an aluminum source, is simultaneously supplied to form an aluminum
oxide film.
[0044] From the drawing, it can be seen that the growth rate of the
aluminum oxide by adding the NH.sub.3 reaction gas to the aluminum
source gas is higher that the growth rate of the aluminum oxide
film formed only by a conventional aluminum source.
[0045] FIG. 4 is a characteristic graph shown to compare the
penetration ratio of hydrogen depending on the type of gas to form
an aluminum oxide film.
[0046] A reference numeral H1 indicates a hydrogen concentration
characteristic curve depending on a conventional hydrogen
penetration, and a reference numeral H2 indicates a hydrogen
concentration characteristic curve depending on a hydrogen
penetration according to the disclosed method. This graph is the
result of an experiment for examining the effect of penetration
prohibition of hydrogen atoms into an aluminum oxide film for a
capacitor in a high-integration memory device such as DRAM, FeRAM,
etc. The experiment process includes forming an aluminum oxide film
on a semiconductor substrate in thickness of about 50 nm by a
conventional method and a method according to the disclosed method,
and generating plasma to penetrate hydrogen atoms into the aluminum
oxide film. For generation of plasma, a power of about 500 W is
applied in the RF reactor and the exposure time is about 100
seconds.
[0047] From the drawing, it can be seen that, as a result of
measuring the concentration of hydrogen within the semiconductor
substrate region 1 and the aluminum oxide film 2, the effect of
hydrogen prohibition of the aluminum oxide film formed according to
the disclosed method is superior to the aluminum oxide film formed
according to the conventional method
[0048] Alternatively, in the above embodiment, the NH3 activation
gas is not supplied simultaneously with the aluminum source, but
H.sub.2O may be simultaneously supplied with the aluminum source in
the supply step of oxygen reaction gas. Also, the NH.sub.3
activation gas is not supplied simultaneously with the aluminum
source or H.sub.2O, but N.sub.2 gas may be simultaneously with the
aluminum source in the first purge step or in the second purge step
to form an aluminum oxide film.
[0049] As mentioned above, the disclosed method supplies a NH.sub.3
reaction gas simultaneously with an aluminum source when an
aluminum oxide film is formed. Therefore, the disclosed method can
improve the growth rate and also improve the characteristic of
prohibiting penetration of hydrogen atoms, thus improving an
electrical characteristic of a semiconductor device.
[0050] The disclosed method has been described with reference to a
particular embodiment in connection with a particular application.
Those having ordinary skill in the art and access to the teachings
of the disclosed method will recognize additional modifications and
applications within the scope thereof.
[0051] It is therefore intended by the appended claims to cover any
and all such applications, modifications, and embodiments within
the scope of the disclosed method.
* * * * *