JP3242333B2 - Compound semiconductor vapor phase growth apparatus and growth method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vapor phase growth of a compound semiconductor material used for a light emitting device and a high frequency device, and more particularly to a vapor phase growth apparatus and a vapor phase growth method for growing a thin film with good controllability. It concerns the growth method.

[0002]

2. Description of the Related Art As a method for growing a compound semiconductor material, a metal organic chemical vapor deposition method is well known, and is used for manufacturing various devices. In order to improve the device performance, it is necessary to grow a plurality of thin films having different compositions of about several tens of degrees, such as a quantum well structure.

Conventionally, this quantum well structure has been formed by alternately switching the valves on the cation source gas supply side, and by appropriately selecting the supply amount (flow rate × time) of the source gas, a predetermined value is obtained. A multilayer film having a layer thickness is obtained.

FIG. 4 is a schematic view of a vapor phase growth apparatus for growing a GaAs / AlAs quantum well structure. In this apparatus, TMG (trimethylgallium:
Ga (CH ₃ ) ₃ , hereinafter referred to as TMG), and TMA (trimethylaluminum: Al (CH ₃ ) ₃ ,
Hereinafter, referred to as TMA) from a cation (cation) source gas line 100, and arsine (A) as an As source.
SH ₃ ) is converted to an anion (anion) raw material gas line 101.
To the growth chamber 102 and supply it onto the GaAs substrate 103.

By alternately opening and closing the valves A and B, the TM is alternately switched at the timing shown in FIG.
By introducing G and TMA into the growth chamber 102, GaAs and AlAs are grown alternately on the GaAs substrate 103, respectively. Here, introduces a A _S H ₃ gas is for the following purposes.

Namely, A _S H ₃ gas is GaAs, of As for growing AlAs material (anion material),
When TMG and TMA, which are cationic raw materials, are not flowing,
That What flowed A _S H ₃ even non growth (during growth interruption) is, GaAs which is heated to a growth temperature is to suppress desorption of As from AlAs crystal (As the vapor pressure High and easily detached from the crystal at high temperatures).

[0007]

However, in the above method, since the gas supply is controlled by opening and closing the valve, the frequency of opening and closing the valve becomes extremely high when thin layers having different compositions are grown in multiple layers. If the frequency of opening and closing of the valve is high, the valve is quickly deteriorated, and the reliability of the device is reduced. As a result, the performance of the device is reduced.

An object of the present invention is to provide a vapor phase growth apparatus and a vapor phase growth method for alternately supplying different source gases onto a substrate without requiring frequent opening and closing of such a valve. is there.

[0009]

In order to achieve the above object, a compound semiconductor vapor deposition apparatus according to the present invention has a plurality of separation growth chambers separated by a partition plate. A gas inlet for introducing a source gas, and an exhaust port for guiding the source gas supplied to each separation and growth chamber in a direction away from the other separation and growth chambers and exhausting the same to the outside are provided. I do.

As described above, since the raw material gas supplied to each of the separation growth chambers is guided in a direction away from the other separation and growth chambers and exhausted to the outside, the partition plate does not completely separate the separation and growth chambers. However, the source gases in each of the separate growth chambers do not mix with each other, and individual vapor growth in each of the separate growth chambers can be reliably performed.

More specifically, the partition plate includes a standing partition plate, and a donut-shaped substrate mounting rotary plate rotatable around the bottom of the partition plate. The partition plate is separated by the partition plate. A gas inlet for introducing a raw material gas is provided in the vicinity of the partition plate in each of the separation and growth chambers, and an exhaust port is provided near the outer periphery of the rotating plate so as to face the gas inlet. It is characterized by becoming.

As described above, when the rotating plate on which the substrate is placed performs the rotating operation, the substrate placed on the rotating plate moves around the outer peripheral portion of the partition plate that is not partitioned by the partition plate, and each of the substrates grows separately. Since the cells pass through the chambers, they can be easily moved to each of the separation and growth chambers, and the multilayer film can be easily grown. In addition, since it is not necessary to frequently open and close the control valve as in the related art, the reliability does not decrease as a result, and stable vapor phase growth can be performed.

Here, the partition plate is a single plate, and two separate growth chambers separated by the partition plate are provided, and first exhaust ports are provided at two locations substantially orthogonal to the plane portion of the partition plate. And two second exhaust ports are provided near the outer periphery of the rotating plate at a position shifted by about 90 ° from the first exhaust port.

As described above, when two kinds of films are grown alternately, the structure of the present invention can be realized by a simple structure having two chambers using only one plate. Also, the second
In the case where one kind of thick film is formed by providing the above-described exhaust ports, it is possible to cope by performing simultaneous exhaust from both the first and second exhaust ports.

As a vapor phase growth method using the above-described compound semiconductor vapor phase growth apparatus, a raw material gas is supplied from the gas inlet to each of the separated growth chambers separated by the partition plate, and at the same time, the supplied gas is supplied. By evacuating to the outside from the exhaust port of each separation growth chamber, a flow of the source gas from the vicinity of the partition plate toward the exhaust port is formed for each separation growth chamber. After performing vapor phase growth, the substrate is moved to another separation growth chamber by rotating a rotating plate, and another vapor phase growth is performed.

According to such a method, a gas flow is formed in a direction away from each other in each of the separation growth chambers, so that gas regions which do not intersect are provided. Then, since the substrate mounted on the rotating plate passes through this gas flow, the multilayer film can be formed without the need to frequently open and close the control valve as in the related art by only a simple operation of simply rotating. Can be easily grown.

Further, the two parts separated by one partition plate
In the above-mentioned growth apparatus provided with separate growth chambers, the same raw material gas is supplied to each of the separation growth chambers from the gas introduction port, and the supply gas is supplied to the outside from the first and second exhaust ports. By evacuating, a flow of the raw material gas is formed from the vicinity of the partition plate to the outer periphery of the rotary plate, and in this state, the rotary plate is rotated to perform vapor phase growth on the substrate.

According to such a method, a gas flow from the vicinity of the partition plate to the outer periphery of the rotary plate is formed. Since the substrate mounted on the rotating plate passes through the gas flow, it is possible to easily cope with the case where a thick film is formed.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A feature of the present invention is that a plurality of separation and growth chambers separated by a partition plate are provided, and the source gases introduced into each of the separation and growth chambers are separated so that they do not cross each other. In this state, a gas flow is formed in this direction, and in this state, the substrate is brought into contact with the source gas sequentially. Hereinafter, a specific description will be given with reference to the drawings.

FIGS. 1A and 1B are a perspective view and a top view, respectively, of a vapor phase growth apparatus according to one embodiment of the present invention. As shown in FIGS. 1A and 1B, a partition plate 2 is erected and fixed at the center of a growth chamber 1. This partition plate has a structure in which the growth chamber 1 is divided into two separate growth chambers 1a and 1b. A donut-shaped rotary plate 3 is provided on the outer periphery of the bottom of the partition plate 2. The rotating plate 3 can rotate around the outer periphery of the fixed plate 2, and the GaAs substrate 4 is mounted thereon.

A plurality of gas inlets are provided near the partition plate 2. First, TM from gas inlet 5
G, gas inlets 6 and 7 through arsine gas and gas inlet 8
From the gas inlet 9 and hydrogen gas from the gas inlet 9
To be introduced. Here, the tips of the TMG gas inlet 5 and the TMA gas inlet 8 are positioned lower than the upper end of the partition plate 2. The inlets 6 and 7 for arsine gas and the inlet 9 for hydrogen gas are provided at a position higher than the partition plate 2.

These gas inlets are arranged such that the source gas inlets 5, 6, 7 and 8 are orthogonal to the partition plate 2, as is apparent from FIG. On this extension, exhaust ports 10 and 11 serving as first exhaust ports are provided near the outer periphery of the rotating plate 3. An exhaust port 1 serving as a second exhaust port is provided near the outer periphery of the rotary plate 3 on the extension of the partition plate 2.
2, 13 are provided. Each of these exhaust ports can be independently opened and closed, and the amount of exhaust can be controlled.

A growth method using the vapor growth apparatus having the above structure will be described below. First, each source gas and hydrogen gas are supplied from each inlet. At this time, the exhaust ports 10 and 11
, And the exhaust ports 12 and 13 are closed. As a result, as shown in FIG.
The MG gas and the arsine gas supplied from the gas inlet 6 form a high-speed gas flow toward the exhaust port 10 and are quickly exhausted, so that convection does not occur on the separation growth chamber 1a side.

On the other hand, the TMA supplied from the gas inlet 8
Gas and arsine gas supplied from the gas inlet 7 are also
Similarly, since a high-speed gas flow flows toward the exhaust port 11 and the gas is quickly exhausted, no convection occurs on the separation growth chamber 1b side.

Since the two gas flows flow in opposite directions across the partition plate 2, the TMG gas flow and the TMA gas flow are not mixed, and the high-speed gas regions of TMG + arsine and TMA + arsine are formed, respectively. it can.

The region of the source gas as described above is defined as GaAs.
By rotating the rotating plate 3 on which the substrate 4 is placed,
On the GaAs substrate 4, a gas flow of TMG + arsine (on the side of the separation growth chamber 1a) and a gas flow of TMA + arsine (on the side of the separation growth chamber 1b) are alternately supplied, and the GaAs layer and the Al
As layers are grown alternately. Here, by appropriately selecting the gas supply amounts of TMG and TMA and the rotation speed of the rotating plate 3, a multilayer thin film having a predetermined layer thickness can be grown.

Next, specific experimental results will be described. The pressure in the growth chamber 1 is 20 torr, the rotation speed of the rotating plate 3 is 6 revolutions per minute, the flow rate of TMG is 20 sccm, and TMA is used.
Flow rate of 60 sccm and arsine gas flow rate of 300 s
Ccm, and TMG, TMA and arsine gas are each accelerated by 5 SLM of hydrogen gas. Separating hydrogen gas supplied from the gas inlet 9 also flows at 5 SLM.

Then, the temperature of the GaAs substrate 4 is set to 600-600.
When grown at 700 ° C., per rotation of the rotating plate 3,
30 ° thick GaAs layer and 20 ° thick AlAs
Alternating layers were observed.

In the above embodiment, the alternate growth of GaAs / AlAs has been described. However, instead of TMA, TMG + T
By flowing a mixed gas of MA, it becomes possible to perform alternate growth of GaAs / AlGaAs.

FIG. 3 is a conceptual diagram for explaining another method of using the vapor phase growth apparatus shown in FIG. That is, in the case where a thick film of AlGaAs is simply grown instead of the alternate growth of GaAs / AlAs according to the above-described embodiment as described in FIG. 2, the exhaust ports 10, 11, 12 and 13 are all opened. Then, the same amount of TMG + TM is supplied to the gas inlets 5 and 8.
The mixed gas of A is allowed to flow, and growth is performed without flowing hydrogen from the hydrogen gas inlet 9 for separation, while the gas in the growth chamber 1 is uniformly exhausted from all the exhaust ports 10 to 13.

The gas flow in the growth chamber 1 in this case is shown in FIG.
As shown in FIG. 2, the flow is uniform toward the outer periphery of the rotating plate 3. By rotating the rotating plate 3 on which the GaAs substrate 4 is mounted in the gas flow, an AlGaAs layer is formed on the GaAs substrate 4. Can be continuously grown.

In each of the above embodiments, the case of AlGaAs is shown, but it goes without saying that the present invention can be applied to the case where another material is used.

As described above, according to the present invention, a plurality of compound semiconductor source gases are independently supplied to the separation region of the rotating plate, while the rotating plate on which the substrate is mounted is rotated. By alternately contacting each source gas with the substrate, the growth of a multilayer thin film such as a quantum well structure can be realized.

That is, the compound semiconductor can be easily grown without frequently opening and closing the control valve of the supply gas as in the prior art.
Deterioration of device characteristics can be avoided. Therefore, a high performance light emitting device and a high frequency device can be provided. The control factors for the growth according to the present invention are the growth pressure of the growth chamber, the substrate temperature, the gas flow rate, and the number of rotations of the rotating plate, all of which are easily controllable.

In addition, by setting the opening and closing of the exhaust port in advance, it is possible to easily cope with normal thick film growth.

[0036]

As described above, according to the present invention, unlike the conventional compound semiconductor growth apparatus, the compound semiconductor can be easily grown without frequently opening and closing the control valve of the supply gas. It is possible to avoid a decrease in reliability due to opening and closing of the control valve. Therefore, a high performance light emitting device and a high frequency device can be provided.

[Brief description of the drawings]

1A and 1B are a perspective view and a top view, respectively, of a compound semiconductor growth apparatus according to an embodiment of the present invention.

FIG. 2 is a top view for explaining a gas flow in one manufacturing method using the compound semiconductor growth apparatus of FIG.

FIG. 3 is a top view for explaining a gas flow in another manufacturing method using the compound semiconductor growth apparatus of FIG. 1;

FIG. 4 is a conceptual diagram of a conventional compound semiconductor growth apparatus.

FIG. 5 is a schematic diagram showing gas supply timings in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Growth chamber 1a, 1b Separation growth chamber 3 Rotating plate 4 Substrate 5, 6, 7, 8 Gas introduction port 10, 11 First exhaust port 12, 13 Second exhaust port

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-181076 (JP, A) JP-A-7-321045 (JP, A) JP-A-6-135795 (JP, A) JP-A-3-3 173419 (JP, A) JP-A-3-130367 (JP, A) JP-A-4-338636 (JP, A) JP-A-4-287912 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/205 C23C 16/44 H01L 33/00

Claims (4)

(57) [Claims] 1. A partition plate provided upright, and a rotating plate for mounting a donut-shaped substrate rotatable around an outer periphery of a bottom portion of the partition plate, and each separated growth separated by the partition plate. A gas inlet for introducing a raw material gas is provided in the vicinity of the partition plate of the chamber, while the raw material supplied to each of the separate growth chambers is disposed near the outer periphery of the rotating plate so as to face the gas inlet. An exhaust port for guiding a gas in a direction away from another separation growth chamber is provided. 2. The partition plate is a single plate, and two separated growth chambers are separated from each other, and first exhaust ports are provided at two locations substantially orthogonal to a plane portion of the partition plate. 2. The compound semiconductor vapor deposition according to claim 1 , wherein two second exhaust ports are provided near the outer periphery of the rotating plate at a position shifted from the first exhaust port by approximately 90 °. 3. apparatus. 3. A vapor deposition method using the compound semiconductor vapor deposition apparatus according to claim 1 , wherein a source gas is supplied from the gas inlet to each of the separated growth chambers separated by the partition plate. By exhausting the supply gas from the exhaust port of each separation growth chamber to the outside,
The flow of the source gas from the vicinity of the partition plate toward the exhaust port is formed for each separation growth chamber, and in this state, the vapor phase growth is performed on the substrate in one separation growth chamber, and then the rotating plate is rotated. Wherein the substrate is moved to another separation and growth chamber to perform another vapor phase growth. 4. The vapor deposition method using the compound semiconductor vapor deposition apparatus according to claim 2 , wherein the same source gas is supplied to each of the two separate growth chambers from the gas inlet while simultaneously supplying the same. By exhausting the gas from the first and second exhaust ports to the outside, a flow of the source gas from the vicinity of the partition plate to the outer periphery of the rotary plate is formed. A vapor phase growth method for a compound semiconductor, comprising performing phase growth.