JP2002083778A - Semiconductor manufacturing method, manufacturing apparatus thereof, and semiconductor element manufacturing method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the need to re-produce a reactor even if process conditions such as flow rate or pressure of raw material gas are changed so as to obtain optimum process conditions in a horizontal reactor. . SOLUTION: In a method for manufacturing a semiconductor according to the present invention, a source gas is introduced into a substrate substantially parallel to a substrate surface to form a deposited film on the substrate. When changing the process conditions such as the flow rate or the pressure of the source gas, the flow rate and the pressure of the source gas in the reaction furnace are changed so that the flow rate of the source gas becomes substantially constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method for growing a semiconductor while introducing a source gas onto a substrate substantially parallel to the substrate surface, an apparatus for manufacturing the same, and a semiconductor element manufacturing method.

[0002]

2. Description of the Related Art A II-VI compound or III-V compound semiconductor is a semiconductor having a large energy gap and a direct transition type, and is considered to be promising as a light emitting material having an emission wavelength ranging from the visible region to the ultraviolet region.

In particular, gallium (Ga) is used as a group III element.
III-V nitride semiconductors that include nitrogen and aluminum (Al) and that contain nitrogen (N) as a group V element have been attracting attention.
There is a need for a method for producing a nitride semiconductor having excellent crystallography.

Among them, metal organic chemical vapor deposition (MOCV)
The D) method is being researched and developed in various fields as a powerful method that can be realized industrially.

A so-called horizontal reaction furnace, which is a conventional MOCVD semiconductor manufacturing apparatus for introducing a raw material gas in parallel with a substrate surface, will be described below with reference to the drawings.

As shown in FIGS. 7A and 7B,
The horizontal reactor 200 includes a reactor main body 201, a gas introduction pipe 202 having a gas inlet 221, and a reactor main body 201.
And a susceptor 211 fitted to the bottom of the susceptor. Here, the reactor main body 201 and the gas introduction pipe 202 are formed of, for example, quartz glass. Further, a gas outlet 212 is provided at an end of the reaction furnace main body 201 opposite to the gas introduction pipe 202.

The susceptor 211 has a wafer 10 on its upper surface.
While maintaining 0, the wafer 100 is heated to a predetermined temperature by a heater.

[0008] The source gas 101 introduced from the gas inlet 221 forms a laminar flow in which no vortex is generated in the gas flow until it reaches the upper part of the susceptor 211 from the gas inlet 221. In order to realize excellent crystal growth, it is necessary that the velocity distribution of the gas flow and the supply amount of the source gas be spatially uniform.

However, the opening width of the gas inlet 221 is a relatively small size determined by the manufacturing standard of the gas pipe, and it is necessary to increase the opening width to be equal to or larger than the width of the susceptor 211. As a result, a widening portion 222 is formed in the gas introduction pipe 202, the width of which increases with increasing distance from the gas introduction port 221 toward the susceptor 211. At this time, if the spread angle α of the spread portion 222 is large, FIG.
As shown in (a), in the flow boundary layer near the inner wall surface of the expanding portion 222, the streamline along the wall surface is separated from the wall surface at a certain separation point, and flows back toward the gas inlet 221 to separate the gas. A streamline (vortex streamline) 102 is formed, and the inside of a curved surface formed by the separated streamline 102 becomes a wake, that is, a vortex 103. In other words, a backflow occurs upstream along the wall surface of the expanding portion 222, and the backflow is separated from the wall surface at a certain separation point to form the separated streamline 102. Although the streamline of the gas introduction pipe 202 is shown only on the wall surface on the left side with respect to the gas flow, a streamline that is almost line-symmetric also occurs on the wall surface on the right side.

When the vortex 103 is generated in the expanding portion 222, the gas flow path is substantially narrowed or deformed, so that the velocity distribution of the gas flow on the susceptor 211 and the spatial distribution of the raw material gas supply amount are reduced. Does not satisfy the required uniformity. Furthermore, since the source gas 101 stays inside the vortex 103, switching from one source gas to another source gas cannot be performed quickly, so that the profile of the interface when changing the composition of the growing semiconductor is changed. Cannot be changed abruptly.

To solve these problems, for example,
Author GBStringfellow, Title Organometallic Vapor-Ph
ase Epitaxy, Second Edition, (p.364), Publisher Acade
In micPress, the spread angle α shown in FIG.
It has been proposed to adopt a configuration in which the side wall of the expanding portion 222 is gently expanded.

As another solution, as shown in FIGS. 8 (a) and 8 (b), or FIGS. 9 (a) and 9 (b), a net-shaped Alternatively, by providing a porous diffusion material (diffuser) 223, vortices generated in the gas flow of the expanding portion 222 are prevented.

[0013]

However, in the conventional horizontal reactor 200, when the spread angle α of the expanding portion 222 is set to about 7 ° or less, the horizontal reactor 200 has a gas inlet 221 to a gas outlet 212. However, since the length dimension becomes large, there is a problem that the installation area becomes large or the device is easily broken, and handling becomes difficult.

On the other hand, the diffusion material 2
Although the gas flow velocity distribution and the spatial uniformity of the raw material gas supply amount are improved by providing the gas flow, the gas flow is reflected by the diffusion material 223 to generate a new vortex. There is a problem that switching from the source gas to another source gas cannot be performed quickly.

In addition, changing the process conditions such as the flow rate or pressure of the raw material gas and re-fabricating the horizontal reactor 200 every time the optimization is attempted leads to a decrease in productivity, that is, an increase in cost. Will be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a horizontal type reactor which is capable of obtaining optimum process conditions even if process conditions such as flow rate or pressure of raw material gas are changed. The object is to eliminate the need to rebuild the furnace.

[0017]

In order to achieve the above-mentioned object, the present invention provides a method of manufacturing a semiconductor device, wherein a product of a flow rate and a pressure of a source gas in a reactor is kept constant, thereby controlling a gas flow rate to a predetermined value. The value is maintained.

The inventors of the present invention have studied various processes for forming a compound semiconductor using a horizontal reaction furnace. As a result, the gas flow, temperature, raw material gas type, and new gas type generated by the chemical reaction in the reaction furnace were determined. And that the spatial distribution of the film thickness deposited on the substrate is substantially controlled by the gas flow rate proportional to the flow rate and pressure of the source gas in the reactor. Therefore, if the flow rate or pressure of the source gas is changed so as to maintain a predetermined value of the gas flow rate, these spatial distributions hardly change during film formation.

More specifically, the first method of manufacturing a semiconductor according to the present invention is a method of manufacturing a semiconductor, in which a source gas is introduced into a substrate substantially parallel to the substrate surface to form a deposited film on the substrate. Targeting the method, when changing the flow rate or pressure of the source gas, so that the flow rate of the source gas is substantially constant,
Change the flow rate and pressure of the source gas.

According to the first semiconductor manufacturing method, when changing the flow rate or the pressure of the source gas, the flow rate of the source gas in the gas inlet is adjusted so that the flow rate of the source gas introduced onto the substrate becomes substantially constant. From the above findings, it is possible to obtain a deposited film having a uniform film thickness even when the gas flow rate is changed to increase the film forming rate because the pressure and the pressure in the reactor are changed. As a result, there is no need to rebuild the reactor every time process conditions change.

In the first semiconductor manufacturing method, it is preferable that the pressure of the source gas is set in a range from about 0.01 atm to about 2 atm.

According to a second method for manufacturing a semiconductor according to the present invention,
By introducing a source gas onto the substrate substantially parallel to the substrate surface, the method is intended for a semiconductor manufacturing method in which a deposited film is formed on a substrate. A first flow rate and a first pressure at which the film thickness becomes substantially uniform, a reference flow rate determining step using a flow rate of the raw material gas satisfying the determined first flow rate and the first pressure as a reference flow rate;
Changing the flow rate and the first pressure so as not to change the reference flow rate, changing the flow rate and the first pressure to a second flow rate different from the first flow rate, and changing the flow rate and the first pressure to a second pressure different from the first pressure. And forming a deposition film on the substrate by introducing the source gas onto the substrate while satisfying the second flow rate, the second pressure, and the reference flow rate.

According to the second semiconductor manufacturing method, the first flow rate and the first pressure at which the thickness of the deposited film becomes substantially uniform are obtained in advance, and the obtained first flow rate and the first pressure are satisfied. The flow rate of the raw material gas is determined as a reference flow rate, and the first flow rate and the first pressure are changed so as not to change the reference flow rate, so that the second flow rate and the first pressure are different from the first flow rate. The pressure is changed to a different second pressure. Thereafter, the source gas is introduced onto the substrate while satisfying the second flow rate, the second pressure, and the reference flow rate to form a deposited film. Therefore, even if the flow rate and the pressure of the source gas are changed, the thickness of the deposited film is changed. Can be made uniform for each film formation. As a result, there is no need to rebuild the reactor every time process conditions change.

In the second method for manufacturing a semiconductor, the reference flow rate determining step preferably sets the initial value of the first pressure to a value of 1 atm or less to determine the first flow rate. As described above, when determining the reference flow rate, first, the initial value of the first pressure is set to a value of 1 atm or less, and then the first pressure is set to the first pressure.
It is the opposite to determine the first flow rate while changing the flow rate of the first pressure, that is, set the initial value of the first pressure to a value of 1 atm or more, and then change the first flow rate while changing the first flow rate.
It is easier to determine the reference flow rate than to determine the flow velocity.

In the second method for manufacturing a semiconductor, it is preferable that the first pressure and the second pressure are set in a range from about 0.01 atm to about 2 atm.

In the method of manufacturing a semiconductor device according to the present invention, a semiconductor device is formed by depositing a plurality of deposition films on a substrate by introducing a source gas onto the substrate substantially parallel to the substrate surface. Targeting the method of manufacturing a semiconductor device, the first flow rate and the first pressure are adjusted by adjusting the flow rate and the pressure of the first source gas so that the thickness of each deposited film is substantially uniform.
A reference flow rate determining step of setting the flow rate of the first raw material gas satisfying the first flow rate and the first pressure obtained as a reference flow rate, and a second flow rate having a viscosity substantially equal to the viscosity of the first raw material gas. The source gas is changed to a second flow rate different from the first flow rate and a second flow rate different from the first pressure so as not to change the reference flow rate.
A first changing step of changing the pressure to the first pressure, and introducing the second source gas onto the substrate while satisfying the second flow rate, the second pressure and the reference flow rate, thereby forming the first deposited film on the substrate. A first film forming step to be formed and a third source gas having a viscosity substantially the same as the viscosity of the first source gas are applied to a third source gas having a second flow rate different from the second flow rate so as not to change the reference flow rate. The second pressure is changed to a third pressure different from the second pressure while being changed to the flow velocity.
And introducing the third source gas onto the first deposited film while satisfying the third flow rate, the third pressure, and the reference flow rate, so that the second deposited film is formed on the first deposited film. And a second film forming step of forming

According to the method of manufacturing a semiconductor device of the present invention,
While satisfying the reference flow rate determined by the first source gas, a first deposition film is formed at a second flow rate and a second pressure using the second source gas, and the third source gas is formed. Is used to form the second deposited film at the third flow rate and the third pressure, so that the film quality of each deposited film in a semiconductor device having a plurality of deposited films deposited thereon is maintained while maintaining the uniformity of the thickness. Can be improved.

Here, the second raw material gas or the third raw material gas having substantially the same viscosity as that of the first raw material gas means the following two cases. In the first case, the second
Alternatively, although the third source gas is different from the molecular species of the first source gas, the viscosity of the gas composed of the second or third molecular species is substantially the same as the viscosity of the first source gas. This is the case. In the second case, the first raw material gas is composed of a small amount of a certain molecular species diluted with a large amount of carrier gas. Therefore, the viscosity of the first raw material gas is determined by the viscosity of the carrier gas. It is determined. On the other hand, the second or third source gas is formed by diluting another molecular species different from the molecular species of the first source gas with a large amount of carrier gas having the same composition as that of the first source gas. ,
This is the case where the viscosity of the second or third source gas is also determined by the viscosity of the carrier gas.

In the method for manufacturing a semiconductor device according to the present invention,
The first deposited film and the second deposited film are made of a group III element and a group V element, the second source gas contains gallium and indium as a group III source, and the second pressure is about 0.3 atm or more. Preferably, the third source gas contains gallium and aluminum in the group III source, the third pressure is about 1.0 atm or less, and the second pressure is not less than the third pressure.

In the method for manufacturing a semiconductor device according to the present invention,
The first pressure, the second pressure and the third pressure are set to about 0.01a
It is preferable to set in the range of tm to about 2 atm.

The semiconductor manufacturing apparatus of the present invention is directed to a semiconductor manufacturing apparatus that forms a deposited film on a substrate by introducing a source gas onto the substrate substantially parallel to the substrate surface. And a flow rate adjusting means for adjusting the flow rate of the source gas such that the flow rate of the source gas near the gas inlet of the reaction furnace is substantially constant. Pressure adjusting means for adjusting the pressure of the gas in the reaction furnace.

According to the semiconductor manufacturing apparatus of the present invention, when changing the flow rate or the pressure of the source gas, the flow rate of the source gas near the gas inlet of the reaction furnace is made substantially constant. Since a flow rate adjusting means for adjusting the pressure and a pressure adjusting means for adjusting the pressure of the source gas in the reaction furnace are provided, a deposited film having a uniform film thickness can be obtained even when the process conditions are changed. As a result, there is no need to rebuild the reactor every time the process conditions are changed.

[0033]

(First Embodiment) A first embodiment of the present invention.
An embodiment will be described with reference to the drawings.

FIGS. 1A and 1B show a first embodiment of the present invention.
(A) is a semiconductor manufacturing apparatus according to the embodiment of FIG.
1A shows a plan configuration of a horizontal reactor for OCVD, and FIG. 1B shows a cross-sectional configuration taken along line Ib-Ib in FIG.

As shown in FIGS. 1A and 1B,
The horizontal reactor 10 includes a reactor main body 11 and a gas inlet 21.
Gas introduction pipe 12 having
And a susceptor 31 made of, for example, carbon for heating 0. Here, the reactor main body 11 and the gas introduction pipe 12 are formed of, for example, quartz glass.

An opening is provided at the bottom of the reactor main body 11, and a susceptor 31 whose bottom is heated by a heater (not shown) or the like holds a wafer 100 inside the reactor main body 11. Exposed and the height of the upper surface is the reactor body 1
1 are fitted so as to be aligned with the bottom surface.

A gas outlet 13 is provided at an end of the reactor main body 11 opposite to the gas introduction pipe 12.

The gas introduction pipe 12 has a gas introduction port 21 whose opening diameter is smaller than the width of the susceptor 31 determined by the production standard of the gas pipe. Introduce in parallel. The end of the gas inlet pipe 12 opposite to the gas inlet 21 is connected to the reactor main body 11.
And are hermetically welded.

The gas introduction pipe 12 is connected to the gas introduction port 21.
The divergent portion 22 has a widening portion 22 in which the distance between the two wall surfaces gradually increases from the side toward the susceptor 31. Here, the value of the spread angle α between the wall surface of the spread portion 22 and the direction from the gas inlet 21 toward the susceptor 31 is set to about 10 °.

A partition plate 23 is provided inside the gas introduction pipe 12 to partition the interior into an upper passage 12a and a lower passage 12b.

The gas introduction pipe 12 is provided with a first pressure gauge 40A, a first flow rate meter 41A and a first flow meter 42A.
The flow velocity and flow rate of the source gas 101 near the gas inlet 21 are monitored.

Similarly, a second pressure gauge 40B, a second flow meter 41B, and a second flow meter 42B
Is provided, and a raw material gas 101 flowing over the susceptor 31 is provided.
Is monitored for pressure, flow rate and flow rate.

Incidentally, the first pressure gauge 40A and the second pressure gauge 40B generally show substantially equal pressure values.

Here, the first flow meter 41A has a function as a flow rate adjusting means, and the second pressure gauge 40B has a function as a pressure adjusting means.

In the first embodiment, hydrogen and trimethylgallium (TMG) diluted with hydrogen are supplied near the gas inlet 21 at a flow rate of about 6 m / s at the upper passage 12a.
And ammonia (NH ₃ ) gas is introduced into the gas inlet 2
1 and is introduced into the lower passage 12b at a flow velocity of about 6 m / s.

The raw material gas separately introduced into the upper passage 12 a and the lower passage 12 b is supplied to the reactor main body 11 and the gas introduction pipe 12.
Susceptor 31 of the merged gas near the junction with
The flow rate above is adjusted to be about 0.6 m / s. At this time, the internal pressure of the reactor main body 11 is adjusted to be about 0.5 atm.

As shown in FIG.
Are substantially uniform in the reactor main body 11.
Further, on the wafer 100 held on the susceptor 31, the temperature distribution 50, the film thickness distribution 51, and the gas flow lines 110 are formed.
Is spatially substantially uniform.

The temperature distribution 50, the growth film thickness distribution 51, and the gas flow line 110 are shown on only one side of the symmetric axis extending in the traveling direction of the source gas 101 for simplification of the drawing. , A pattern is generated which is symmetrical with respect to the symmetry axis. The same applies hereinafter.

Next, in order to improve the quality of the crystal of the deposited film deposited on the wafer 100, the flow rate of the raw material gas introduced from the gas inlet 21 in the vicinity of the gas inlet 21 is set to about 6
A case where the internal pressure of the reactor main body 11 is increased from about 0.5 atm to about 2.0 atm while maintaining the pressure at m / s will be described.

FIG. 2 shows a temperature distribution 50 and a grown film thickness distribution 51 in the horizontal reactor 10 when only the gas pressure is increased.
And a gas streamline 110.

As shown in FIG. 2, the gas flow lines 110 along the wall surface in the flow boundary layer near the wall surface of the gas introduction pipe 12
However, at a certain separation point, the vortex 110a is separated from the wall surface and extends downstream, and a vortex 110a is generated.

When the vortex 110a is generated and the gas flow path is substantially narrowed or the gas flow line 110 is deformed, the velocity distribution of the gas flow line 110 on the susceptor 31, that is, the raw material gas The spatial uniformity of the supply is degraded. In particular, in the reactor main body 11, since the gas flow velocity in the portion along the axis of symmetry of the gas flow line 110 increases, the temperature of the gas does not rise to a predetermined value, and the cold gas concentrates on the central portion of the susceptor 31. Will be introduced. Therefore, FIG.
The temperature distribution 50 and the film thickness distribution 51 shown in FIG.
At the center of the uniformity collapsed greatly, and as a result,
It is difficult to maintain uniformity of the thickness and quality of the deposited film.

In addition, as described above, when the vortex 110a is generated, the source gas stays inside the vortex 110a, and the source gas cannot be switched quickly, so that the composition of the growing semiconductor is changed. In this case, the profile of the interface cannot be changed sharply.

Therefore, as shown in FIG. 3, in the first embodiment, the internal pressure of the reactor main body 11 is set to about 2.0 a.
tm, and the gas inlet 2 is adjusted so that the flow rate of the gas introduced from the gas inlet 21 is the same as that in FIG.
The flow velocity of the gas near 1 is about 6 m / s to about 1.5 m / s.
m / s. Here, the fact that the gas flow rate is proportional to the gas flow velocity and pressure is used.

That is, the process conditions shown in FIG.
The internal pressure of the reactor main body 11 is set to about 0.5 atm, the flow velocity of the gas near the gas inlet 21 is set to about 6 m / s,
On the other hand, the process conditions shown in FIG.
atm, and the gas flow rate near the gas inlet 21 is about 1.
5 m / s. As described above, in each case, the product of the internal pressure and the gas flow rate is about 3.0, and in the first embodiment, this value is used as an index of the reference flow rate.

Here, when determining the index of the reference flow rate, first, the initial value of the internal pressure is set to a value of 1 atm or less, and then the optimum value is determined while gradually changing the gas flow rate. Is preferred.

As shown in FIG. 3, the vortex 110 a appearing in FIG. 2 has disappeared, and the temperature distribution 50, the growth film thickness distribution 51, and the velocity of the gas stream 110 on the wafer 100 held on the susceptor 31. The distribution becomes substantially uniform spatially, and a good film thickness can be obtained for each wafer as in the case of FIG.

Thus, the internal pressure and the gas flow rate are
By changing the predetermined flow rate so as to be maintained, the quality of the deposited film can be surely improved.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

In the second embodiment, in order to improve the crystal quality and growth rate of the deposited film, the internal pressure of the reactor main body 11 was maintained at about 0.5 atm as compared with the process conditions of FIG. The gas flow velocity near the gas inlet 21 is about 6 m
/ S is increased to about 24 m / s.

FIG. 4 shows a temperature distribution 50 and a grown film thickness distribution 51 in the horizontal reactor 10 when only the gas flow rate is increased.
And a gas streamline 110.

As shown in FIG. 4, the gas flow line 110 along the wall surface of the gas introduction pipe 12 is separated from the wall surface and extends downstream, so that a vortex 110a is generated. Due to the vortex 110a, the gas flow path is substantially narrowed or the gas flow line 1
Due to the deformation of 10, the velocity distribution of the gas flow line 110 on the susceptor 31, that is, the spatial uniformity of the supply of the source gas is deteriorated. In particular, in the reactor main body 11, since the gas flow velocity in the portion along the axis of symmetry of the gas flow line 110 increases, the temperature of the gas does not rise to a predetermined value, and the cold gas concentrates on the central portion of the susceptor 31. Will be introduced. Therefore, the uniformity of the temperature distribution 50 and the film thickness distribution 51 shown in FIG. 4 is largely lost at the central portion of the wafer 100, and it is difficult to maintain the uniformity of the film thickness and film quality of the deposited film. .

At this time, the temperature distribution 50, the growth film thickness distribution 51, and the gas flow line 110 shown in FIG. 4 correspond to the process shown in FIG. 2 where the gas flow rate is about 6 m / s and the internal pressure is about 2.0 atm. It is almost the same as the distribution under the condition.

In addition, as described above, when the vortex 110a is generated, the source gas stays inside the vortex 110a, and the source gas cannot be switched quickly, so that the composition of the growing semiconductor is changed. In this case, the profile of the interface cannot be changed sharply.

Therefore, while maintaining the gas flow rate near the gas inlet 21 at about 24 m / s, the flow rate of the gas introduced from the gas inlet 21 satisfies about 3.0 of the reference flow rate obtained in FIG. Then, the internal pressure of the reactor main body 11 is set to about 0.5 a.
tm to about 0.125 atm.

With this change, as shown in FIG.
The vortex 110a that has appeared in FIG. 1 disappears, and on the wafer 100 held on the susceptor 31, the temperature distribution 50, the growth film thickness distribution 51, and the velocity distribution of the gas streamlines 110 become substantially uniform spatially. Alternatively, as in the case of FIG. 3, a favorable film thickness can be obtained for each wafer.

As described above, according to the first embodiment or the second embodiment, the reference flow rate at which the thickness of the deposited film becomes uniform is set in advance, and a more desirable internal pressure is obtained. When the process conditions are changed, the uniformity of the thickness of the deposited film can be ensured by adjusting the gas flow rate so as to maintain the reference flow rate.

When the process conditions are changed in order to obtain a more desirable gas flow rate, the uniformity of the thickness of the deposited film is ensured by adjusting the internal pressure so as to maintain the reference flow rate. be able to. The internal pressure at this time is preferably set in a range from about 0.01 atm to about 2 atm.

The compound semiconductor to be formed is not limited to the group III-V compound, but may be a group II-VI compound.

(Third Embodiment) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

In the first embodiment and the second embodiment, when changing the process conditions of the deposited film on one wafer and the deposited film on another wafer, the conditions of the gas flow velocity and the pressure are changed. Has been described in the range where the reference flow rate is maintained.

In the third embodiment, when a plurality of deposited films having different compositions are formed on one wafer, a manufacturing method for changing process conditions according to the composition of each deposited film will be described. .

FIGS. 6A and 6B show a third embodiment of the present invention.
3 shows a cross-sectional configuration in a process order of a method of manufacturing a blue-violet semiconductor laser device including a III-V nitride semiconductor according to the embodiment.

First, as shown in FIG. 6A, a substrate 60 made of, for example, sapphire is placed in the horizontal reactor 1 shown in FIG.
0 is held on the susceptor 31. Subsequently, on the substrate 60, a buffer layer 61 made of gallium nitride (GaN),
n-type contact layer 62 made of n-type GaN, n-type clad layer 63 made of n-type aluminum gallium nitride (AlGaN), and a plurality of barrier layers 64a made of AlGaN
And a plurality of well layers 64b made of indium gallium nitride (InGaN) are alternately stacked, a multiple quantum well (MQW) active layer 64, a p-type cladding layer 65 made of p-type AlGaN, and p-type GaN. The p-type contact layer 66 is sequentially grown.

At the time of forming the buffer layer 61, the n-type contact layer 62 and the p-type contact layer 66, trimethyl gallium (TMG) as a Group III source diluted with nitrogen (N ₂ ) gas is supplied from the upper layer gas. The flow velocity near the inlet is about 6
m / s, and ammonia (MH ₃ ) as a Group V source is introduced from the lower passage so that the flow velocity near the gas inlet becomes about 6 m / s. At this time, the internal pressure of the reactor main body is adjusted to about 0.4 atm.

At the time of forming the n-type cladding layer 63, the p-type cladding layer 65, and the barrier layer 64a containing aluminum (Al) in composition, TMG and trimethylaluminum (TMA) diluted with nitrogen gas are used as a group III source. Ammonia was used as the group V source, the gas flow velocity near the gas inlet was about 6 m / s, and the internal pressure of the reactor body was about 0.4 a.
tm.

At the time of forming the well layer 64b containing indium (In) in the composition, TMG and trimethylindium (TMI) diluted with nitrogen gas are used as the group III source.
Ammonia is used as the Group V source. Since indium has a high vapor pressure, the internal pressure is set higher than when indium is not included in the composition. At this time, the index of the reference flow rate is proportional to the product of the gas flow velocity near the gas inlet and the internal pressure of the reactor body, that is, the product of 6 (m / s) × 0.4 (atm). 4 is maintained, the flow velocity of the gas near the gas inlet is about 2 m / s, and the internal pressure of the reactor main body is about 1.2 atm.

Next, as shown in FIG. 6B, the p-type contact layer 66, the p-type cladding layer 65, the MQW active layer 64
And dry etching is selectively performed on the n-type cladding layer 63 to expose the n-type contact layer 62. On the exposed surface, an n-side electrode made of a laminate of titanium (Ti) and aluminum (Al) is formed. 67 is formed. Thereafter, nickel (Ni) and gold (Au) are formed on the p-type contact layer 66.
And a ridge-shaped p-side electrode 68 is formed. However, the order of forming the n-side electrode 67 and the p-side electrode 68 does not matter.

As described above, when forming a semiconductor laser device composed of a plurality of semiconductor layers having different compositions, while maintaining a predetermined value of the reference flow rate of the gas to be introduced according to the composition of each semiconductor layer, By changing the flow rate or the pressure, spatial uniformity of the thickness of the deposited film can be maintained and a high-quality semiconductor film can be obtained.

When the composition of the barrier layer 64a is gallium nitride, trimethylgallium diluted with nitrogen gas and ammonia gas are mixed at a gas flow rate of about 6 m / s near the gas inlet port. Good film quality can be obtained by introducing the internal pressure of the furnace body to about 0.4 atm.

The structure of the resonator of the semiconductor laser device according to the third embodiment is merely an example, and the structure of the MQW active layer 6 is not limited.
4 may be a single quantum well active layer having a single well layer 64b.

The n-type and p-type light guide layers are formed by MQ
The W active layer 64 may be provided so as to sandwich it from above and below,
Further, a current confinement layer may be provided on the MQW active layer 64.

The semiconductor device is not limited to a semiconductor laser device, but may be, for example, a light emitting diode device.

[0084]

According to the method and apparatus for manufacturing a semiconductor according to the present invention, the flow rate and pressure of the source gas are changed so that the flow rate of the source gas introduced from the gas inlet is substantially constant. Even if the flow rate or pressure of the gas is changed, a deposited film having a uniform film thickness can be obtained, so that it is not necessary to re-create a reactor in accordance with a change in process conditions.

[Brief description of the drawings]

FIGS. 1A and 1B show a semiconductor manufacturing apparatus according to a first embodiment of the present invention, and FIG. 1A shows a case where a temperature distribution, a growth film thickness distribution, and a gas streamline are substantially uniform. FIG.
(B) is a sectional view taken along the line Ib-Ib of (a).

FIG. 2 is a plan view showing a state in which uniformity of a temperature distribution, a growth film thickness distribution, and a gas streamline is broken in the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 3 is a plan view showing the semiconductor manufacturing apparatus according to the first embodiment of the present invention, in which the temperature distribution, the growth film thickness distribution, and the uniformity of gas streamlines have been restored.

FIG. 4 is a plan view showing a state in which uniformity of a temperature distribution, a growth film thickness distribution, and a gas streamline is broken in the semiconductor manufacturing apparatus according to the second embodiment of the present invention.

FIG. 5 is a plan view showing a state in which the temperature distribution, the growth film thickness distribution, and the uniformity of gas streamlines have been restored in the semiconductor manufacturing apparatus according to the second embodiment of the present invention.

FIGS. 6A and 6B are cross-sectional views in the order of steps showing a method for manufacturing a semiconductor laser device made of a III-V nitride semiconductor according to a third embodiment of the present invention.

7A and 7B show a conventional semiconductor manufacturing apparatus for MOCVD, wherein FIG. 7A is a plan view, and FIG. 7B is a sectional view taken along line VIIb-VIIb of FIG. 7A.

8A and 8B show a conventional semiconductor manufacturing apparatus for MOCVD, wherein FIG. 8A is a plan view, and FIG. 8B is a cross-sectional view taken along line VIIIb-VIIIb of FIG.

FIGS. 9A and 9B show a conventional MOCVD semiconductor manufacturing apparatus, wherein FIG. 9A is a plan view and FIG. 9B is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Horizontal reactor 11 Reactor main body 12 Gas inlet pipe 12a Upper layer path 12b Lower layer path 13 Gas outlet 21 Gas inlet 22 Expanding part 23 Partition plate 31 Susceptor 40A First pressure gauge 41A First flow rate meter (flow rate adjusting means ) 42A first flow meter 40B second pressure gauge (pressure adjusting means) 41B second flow meter 42B second flow meter 50 temperature distribution 51 film thickness distribution 60 substrate 61 buffer layer 62 n-type contact layer 63 n-type Clad layer 64 multiple quantum well active layer 64a barrier layer 64b well layer 65 p-type clad layer 66 p-type contact layer 67 n-side electrode 68 p-side electrode 100 wafer 101 source gas 110 gas streamline 110a vortex

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yusaburo Ban 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Term (reference) 4K030 CA04 CA12 EA03 JA05 JA09 JA12 LA14 5F041 AA40 CA34 CA40 CA65 5F045 AA04 AB17 AC08 AC12 AE23 AE25 AE30 AF04 AF09 BB02 CA09 DA53 DA54 DA63 DP02 DQ06 EE20 GB05 GB06 5F073 AA72 CA17 DA05

Claims (9)

[Claims] 1. A semiconductor manufacturing method for forming a deposited film on a substrate by introducing a source gas onto a substrate substantially parallel to the substrate surface, wherein the flow rate or pressure of the source gas is changed. In this case, the flow rate and the pressure of the source gas are changed so that the flow rate of the source gas is substantially constant. 2. The pressure of the source gas is about 0.01 atm.
2. The method according to claim 1, wherein the temperature is set in a range from about 2 atm to about 2 atm. 3. A method for manufacturing a semiconductor, comprising forming a deposited film on a substrate by introducing a source gas onto the substrate substantially parallel to the substrate surface, wherein the flow rate and the pressure of the source gas are adjusted. Then, a first flow rate and a first pressure at which the thickness of the deposited film becomes substantially uniform are obtained, and a flow rate of the source gas satisfying the obtained first flow rate and the first pressure is set as a reference flow rate. A flow rate determining step; and changing the first flow rate and the first pressure so as not to change the reference flow rate, and changing a second flow rate different from the first flow rate.
Changing the flow rate to a second pressure different from the first pressure, and changing the source gas onto the substrate while satisfying the second flow rate, the second pressure, and the reference flow rate. A film forming step of forming a deposited film on the substrate by introducing the semiconductor device. 4. The semiconductor according to claim 3, wherein the reference flow rate determining step sets the initial value of the first pressure to a value of 1 atm or less and determines the first flow rate. Manufacturing method. 5. The method of claim 1, wherein the first pressure and the second pressure are about 0.5.
The method according to claim 3, wherein the temperature is set in a range from 01 atm to about 2 atm. 6. A method for manufacturing a semiconductor device, comprising: introducing a source gas onto a substrate substantially in parallel with the substrate surface to form a semiconductor device having a plurality of deposited films deposited on the substrate. Adjusting the flow rate and the pressure of the first source gas to obtain a first flow rate and a first pressure at which the thickness of each of the deposited films becomes substantially uniform; A reference flow rate determining step in which a flow rate of the first source gas satisfying a pressure is set as a reference flow rate; and a second source gas having a viscosity substantially equal to the viscosity of the first source gas is set to the reference flow rate. A first changing step of changing to a second flow rate different from the first flow rate and changing to a second pressure different from the first pressure so as not to change; 2 on the substrate while satisfying the flow rate, the second pressure and the reference flow rate. To form a first deposited film on the substrate.
And a third flow rate different from the second flow rate so as not to change the reference flow rate by applying a third raw material gas having substantially the same viscosity as that of the first raw material gas. And a second changing step of changing the third raw material gas to a third pressure different from the second pressure, while satisfying the third flow rate, the third pressure, and the reference flow rate. A second film-forming step of forming a second deposited film on the first deposited film by introducing the second deposited film on the first deposited film. . 7. The method according to claim 1, wherein the first deposited film and the second deposited film are II
The second source gas contains gallium and indium in a group III source, the second pressure is about 0.3 atm or more, and the third source gas is 7. The method of claim 6, wherein the Group III source comprises gallium and aluminum, and wherein the third pressure is less than about 1.0 atm, and wherein the second pressure is greater than the third pressure. Of manufacturing a semiconductor device. 8. The semiconductor device according to claim 6, wherein the first pressure, the second pressure, and the third pressure are set in a range from about 0.01 atm to about 2 atm. Method. 9. A semiconductor manufacturing apparatus for forming a deposited film on a substrate by introducing a source gas onto the substrate substantially parallel to the substrate surface, wherein the substrate is held inside, A reactor for introducing a source gas onto a substrate; flow rate adjusting means for adjusting a flow rate of the source gas such that a flow rate of the source gas near a gas inlet of the reactor is substantially constant; And a pressure adjusting means for adjusting the pressure in the reaction furnace.