JPH09246193A - Film formation device by chemical gas phase growing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently form various films under optimum conditions at low cost by a method wherein a flow adjusting plate for forming a flow passage of material gas in cooperation with a turn table to which a processing board (wafer) is mounted is movably provided so as to attach to or detach from the turn table by lifting means. SOLUTION: In this formation device by a chemical gas phase growing method, a flow adjusting plate 18 for forming a flow passage of meterial gas 17 in cooperation with a turn table 15 to which a processing board (wafer) 14 is mounted is movably provided so as to attach to or detach separate from the turn table 15 by lifting means 35. As a result, it is possible to adjust a height position of the flow adjusting plate according to the kind of semiconductor elements manufactured, use one device both as a film formation laid stress on quality and producibility, and efficiently form both films under an optimum condition at low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing substrate heated in a film forming tank by bringing the material gas introduced into the film forming tank into contact with the processed substrate to cause a gas phase chemical reaction. The present invention relates to a film forming apparatus using a chemical vapor deposition method (CVD) in which a gallic arsenic compound film or other coating layer is pyrolyzed and produced depending on the type of material gas, such as a semiconductor laser element, a light emitting diode, and an electrolytic cell. Used for manufacturing wafers, which are the raw materials for semiconductor devices such as effect transistors.

[0002]

2. Description of the Related Art In a film forming apparatus of this type by chemical vapor deposition, a wafer, that is, a processing substrate 1 is placed in a film forming tank (not shown) as shown in FIG. The heater 3 is placed below the turntable 2 to be placed.
Is installed, and a diversion plate 5 having an inclined diversion wall 4 formed from the axial center to the outer peripheral side is disposed above the injection port, and the injection port is formed in the axial center of the diversion plate 5. The material gas 7 is sprayed from 6 toward the processing substrate 1 on the turntable 2.

The injected material gas 7 causes a chemical reaction such as decomposition, reduction, oxidation or substitution with respect to the processing substrate 1 while flowing on the turntable 2 in the radial direction from the axial center, and the material substrate concerned. A film is formed on the upper surface of 1 according to the property of the material gas 7.

The quality and productivity at that time depend on conditions such as the pressure in the film forming tank, the density of the material gas, the temperature of the processing substrate 1 and so on. Although the film formation is performed while appropriately controlling it, the dependence on the shape of the film formation tank, especially on the form of the flow control plate 5 forming the flow path of the material gas 7 in contact with the processing substrate 1, is extremely large.

For example, when the pressure and temperature are set high, FIG.
When the flow regulating plate 5 is brought close to the turntable 2 as shown in (a), the cross-sectional area of the material gas 7 injected onto the turntable 2 is small, the density is high, and the flow velocity is slow. Although the growth rate of the film is high and there is an advantage that the film formation can be efficiently performed by consuming the material gas 7 which is small, the processing substrate 1 located on the inner peripheral side which is the upstream side of the flow path.
And the processing substrate 1 located on the outer peripheral side, which is the downstream side, have a difference in film forming conditions, that is, more material gas 7 is consumed on the upstream side, and the inner peripheral side is thick and the outer peripheral side is thin. May be generated.

Further, the pressure and temperature are set to be low, and FIG.
When the flow regulating plate 5 is separated from the turntable 2 as in (b), contrary to the above case, the cross-sectional area of the material gas 7 injected onto the turntable 2 is large and the density is high. Since it is low and the flow velocity is high, the growth rate of the film is slow and only a thin film is produced, and the utilization efficiency of the material gas 7 is not good, so that there is a drawback that a large amount of the material gas 7 needs to be supplied. Since there is no difference in the film forming conditions between the processed substrate 1 located on the inner peripheral side which is the upstream side of the flow path and the processed substrate 1 located on the outer peripheral side which is the downstream side, it is uniform and good from the inner peripheral side to the outer peripheral side. Various film formations can be performed.

[0007]

As in the former case, a mode in which the productivity is high even if the quality is somewhat difficult is, for example, a wafer manufacturing process for a semiconductor device such as a light emitting diode (LED) which does not require high quality. Is valid for, and like the latter,
A mode in which a uniform and high-quality thin film can be obtained even if there is some difficulty in productivity is effective in manufacturing a wafer for a semiconductor device such as a field effect transistor (FET) that requires high quality. In the case of a laser (LD), the energy layers on both sides of the multilayer film are relatively thick films and high quality is not required, but when intermediate layers that are active layers need to be high quality thin films, the former Both the latter aspect and the latter aspect are required.

However, in the conventional device, the flow regulating plate 5 described above is used.
Since the height position was fixed at a certain height, it is possible to prepare multiple units to suit the type of semiconductor element to be manufactured, or to manufacture at the sacrifice of either quality or productivity. Therefore, improvements have been desired in terms of both economical efficiency and performance.

Therefore, in the present invention, the chemical vapor phase is improved so that the film formation suitable for various uses can be efficiently performed by one apparatus, and the above-mentioned problems of the prior art can be solved. The purpose of the present invention is to provide a film forming apparatus by the growth method.

[0010]

In order to solve the above problems, the film forming apparatus by the chemical vapor deposition method of the present invention has achieved the object by using the following means.

In the film forming apparatus using the chemical vapor deposition method of the present invention, the flow regulating plate that forms the flow path of the material gas in cooperation with the turntable on which the processing substrate (wafer) is placed is moved up and down. The turntable can be moved so as to move closer to or away from the turntable.

Accordingly, in the case of the fixed flow regulating plate of the prior art, depending on the type of semiconductor element to be manufactured, the height position of the flow regulating plate requires two units, one for quality and the other for productivity. However, one machine can also be used in common, and when various kinds of film formation are performed with one machine that attaches importance to quality, the problems of excessive quality and marked decrease in productivity can be easily solved, and under the optimal conditions, it becomes efficient and inexpensive. Various film formations can be performed.

As a means for raising and lowering the flow control plate, a material gas feed pipe is attached in such a manner that one end is opened to the axial center of the flow control plate, and the feed pipe for the material gas projected from the film formation tank is attached. When the elevating means is engaged with the other end to make it movable up and down, and the contact type seal member is interposed in the sliding portion between the material gas feed pipe and the film forming tank, It can be provided easily and inexpensively.

Further, if the elevating means is controlled by an NC control device, optimum conditions suitable for various film formations can be easily obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows the overall structure of a film forming apparatus to which the present invention is applied. A film forming tank 13 whose outer periphery is surrounded by a partition wall 11 and a top plate 12 is provided, and the film forming tank 13 is provided with a treatment. A turntable 15 on which the substrate 14 is placed, a heater 49 which is a heating means for the processing substrate 14 on the turntable 15,
A flow regulating plate 18 that forms a flow path for the material gas 17 is accommodated as a main component.

As shown in detail in FIG. 3, the turntable 15 has an inner peripheral plate 15a on which the processing substrate 14 is placed.
And an outer peripheral plate 15c having a tooth profile 16 and a guide groove 19 formed on the outer peripheral surface thereof, and an intermediate plate 15b interposed between the inner peripheral plate 15a and the outer peripheral plate 15c. Both have heat resistance and chemical resistance.

Further, since the inner peripheral plate 15a is required to have high purity and thermal conductivity so as not to contaminate the treated substrate 14, a heat resistant steel material which can easily obtain a purity such as carbon or molybdenum. Desirable to use, outer peripheral plate 15
Since c constitutes a gear, it is desirable to use, for example, stainless steel as a wear-resistant metal material, and the intermediate plate 15b is a heat insulating member that does not transfer heat from the inner peripheral plate 15a side to the outer peripheral plate 15c side, such as a quartz plate. Use of is preferred.

A rotary drive device 21 for rotating the turntable 15 at a speed of, for example, about 20 revolutions per minute is provided on the outer periphery of the turntable 15. The rotary drive device 21 includes a motor 22. The gear 23 connected to the rotary shaft meshes with the tooth profile 16 of the outer peripheral plate 15c to drive the turntable 15 to rotate, and the annular projections 25 of the rollers 24 arranged at a plurality of locations around the outer circumference of the turntable 15 have guide grooves 19 formed therein. The turntable 15 is rotatably supported.

The heater 49 is the film forming tank 1 in this embodiment.
3 uses, for example, an infrared lamp having a capacity for heating to 650 to 750 degrees Celsius, and heats the processing substrate 14 on the turntable 15 through a dustproof plate 26 such as a quartz plate provided above the infraredproof lamp for dustproofing. I am trying to do it.

Regarding the temperature control of the processing substrate 14, the substrate temperature control device 28 controls the heater 49 based on the reference temperature instructed by the main control device 27, and the tip end portion is projected in the center of the film forming tank 13. It is appropriately corrected by the actual measurement value by the temperature sensor 29.

The flow regulating plate 18 is disposed on the turntable 15 and is arranged on the surface facing the turntable 15 so as to be inclined from the axial center toward the outer peripheral side in the radial direction by, for example, 2 to 8 degrees. A supply pipe 3 having a flow wall surface 30 and having an injection port for injecting the material gas 17 toward the processing substrate 14 at the axis center.
One end is attached.

The material gas 17 is a mixed gas of the raw materials containing the components of the coating, and the volatile raw material gas 33 selected by the material gas switching device 32 is mixed with the carrier gas 34, and the feed pipe is supplied. It is brought into contact with the heated processing substrate 14 in the film forming tank 13 via 31 to decompose, reduce, oxidize,
A chemical reaction such as substitution produces a film according to the property of the material gas 17.

In the present invention, the flow regulating plate 18 is fixed at a fixed height position in the prior art, but in the present invention, the flow regulating plate 18 is vertically moved by the elevating means 35 so as to approach or separate from the processing substrate 14 on the turntable 15. The flow path of the material gas 17 by the flow control wall surface 30 can be adjusted according to the type of semiconductor element to be manufactured.

The range for adjusting the height position of the flow regulating plate 18 is
For example, as shown in FIG. 1A, L ₁ = 5 nm at the lower limit position in the state of approaching the turntable, and L ₂ = at the upper limit position in the state of approaching the turntable as in FIG. 1B.
About 50 nm is set as a rough guide.

In the illustrated embodiment, the elevating means 35 has an elevating plate 36 attached to the other end of the feeding pipe 31, and the elevating plate 36
The screw cylinder 37 provided on the motor and the feed screw 40 connected to the motor 38 via the coupling 39 are screwed together to form the motor 3
When the rotating member 8 is driven to rotate, the flow regulating plate 18 moves up and down together with the feeding pipe 31.

The elevating means is not limited to the embodiment shown in the drawings. For example, the elevating plate 36 can be moved up and down by expanding and contracting a cylinder, or a pinion can be attached to a rack having a tooth profile formed on the outer circumference of the feed pipe 31. A known moving mechanism such as a structure in which the gears are meshed can be appropriately used.

The feeding pipe 31 has an intermediate portion slidably supported by a bearing 41, and prevents the inside and outside of the film forming tank 13 from communicating with each other through the sliding portion to prevent the internal pressure from fluctuating. Therefore, a contact-type seal member 42 is attached to the outer periphery of the feed pipe 31 in the film formation tank 13 to keep the sliding portion airtight, and the contact-type seal member 42 can be expanded and contracted in a bellows shape. A bellows made of metal such as stainless steel is used.

The internal pressure of the film forming tank 13 is set in the range of, for example, 50 to 500 Torr according to the type of film formation. For this pressure setting, a pressure adjusting gas such as hydrogen gas is used. 43 is injected into the film forming tank 13 through the feed pipe 44, and the internal pressure is measured by the pressure sensor 45, and the reference pressure S ₁ and the pressure control device 46 set in advance
Are compared, and the pressure difference is controlled so as to be appropriately corrected.

Further, the reacted exhaust gas generated in the film forming tank 13 has a flow rate adjusting valve 47 so that the internal pressure is not changed.
After being discharged to the outside by a vacuum pump via the, the harmful substances are detoxified.

The state of film formation on the processing substrate 1 is determined by, for example, using an optical film pressure measuring meter 48 such as an ellipsometer and the film forming tank 1.
The measurement value S ₁ is measured by mounting it in the inside of the control unit 3 and the case where the film formation is simply confirmed at a predetermined film pressure and the main control unit based on the measurement value S _1. There are two cases in which the setting conditions of No. 27 are varied. In the former case, all film forming conditions are set in a pre-programmed flowchart, and the main controller 27 is set to perform NC control based on this flowchart. Is configured.

In the latter case as well, the NC control is basically performed. For example, when the preset reference membrane pressure and the measured value S ₁ match, control is performed to move to the next step, Input the correlation data between processing time and membrane pressure,
When the measured value S ₁ on the way is deviated, the elevating means 35 is appropriately controlled to accelerate or suppress the membrane pressure generation,
Control is performed so that a predetermined membrane pressure is obtained within a preset reference processing time.

[0033]

EXAMPLE FIG. 4 shows a semiconductor laser wafer.
This is a comparison between the present invention in which the height position of the flow control plate can be changed and the conventional technique that is fixed. Since there is a layer that requires high quality during film formation, the flow control plate in the conventional technique is shown in FIG. The state of a) was set.

As can be seen from this figure, the conventional technique inevitably resulted in excessive quality in the thick layer portion of the membrane pressure, which does not require high quality but rather emphasizes the improvement of work efficiency. However, in the case of the present invention, the growth time can be shortened appropriately and the work efficiency can be improved and the material gas can be effectively used, and the cost can be significantly reduced.

[0035]

As is apparent from the above description, in the film forming apparatus by the chemical vapor deposition method of the present invention, the flow of the material gas is cooperated with the turntable on which the processing substrate (wafer) is placed. The diversion plate forming the path was made movable by the elevating means so as to approach or separate from the turntable.

Therefore, in the case of the fixed flow regulating plate of the prior art, depending on the type of the semiconductor element to be manufactured, the height position of the flow regulating plate requires two units, one for quality and the other for productivity. However, one machine can also be used in common, and when various kinds of film formation are performed with one machine that attaches importance to quality, the problems of excessive quality and marked decrease in productivity can be easily solved, and under the optimal conditions, it becomes efficient and inexpensive. Various film formations can be performed.

As a means for raising and lowering the flow control plate, a material gas feed pipe is attached in such a manner that one end is opened to the axis of the flow control plate, and the feed pipe for the material gas projected from the film formation tank is attached. When the elevating means is engaged with the other end to make it movable up and down, and the contact type seal member is interposed in the sliding portion between the material gas feed pipe and the film forming tank, It can be provided easily and inexpensively.

Further, when the elevating means is controlled by the NC control device, optimum conditions suitable for various film formations can be easily obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a film forming apparatus by a chemical vapor deposition method to which the present invention is applied.

FIG. 2 is a basic configuration diagram of a film forming apparatus by a chemical vapor deposition method which is an object of the present invention.

3 is a perspective view of a turntable portion in the film forming apparatus of FIG.

FIG. 4 is an explanatory diagram comparing a film forming state of the present invention with that of a conventional technique.

[Explanation of symbols]

 11 partition wall 12 top plate 13 film forming tank 14 processing substrate (wafer) 15 turntable 16 tooth profile 17 material gas 18 flow regulating plate 19 guide groove 20 heater 21 rotation drive device 22 motor 23 gear 24 roller 25 annular protrusion 26 dustproof plate 27 main Control device 28 Substrate temperature control device 29 Temperature sensor 30 Control wall 31 Feed pipe 32 Material gas switching device 33 Raw material gas 34 Carrier gas 35 Elevating means 36 Elevating plate 37 Screw cylinder 38 Motor 39 Coupling 40 Feed screw 41 Bearing 42 Seal Member 43 Pressure adjusting gas 44 Feeding pipe 45 Pressure sensor 46 Pressure control device 47 Flow rate adjusting valve 48 Membrane pressure measuring meter

Claims (3)

[Claims] 1. A processing substrate held on a turntable in a film forming tank is heated by a heater, and a material gas is ejected from an ejection port provided at an axial center of a flow regulating plate facing the turntable. A chemical vapor deposition method is used in which a material gas is caused to flow to the outer peripheral side along a flow path formed between the flow control plate and the turntable, and the coating layer is pyrolyzed and produced on the treated substrate by the material gas. A film forming apparatus according to a chemical vapor deposition method, wherein the flow control plate is movable by an elevating means so as to move closer to or away from the turntable. 2. A feed pipe for the material gas, wherein a feed pipe for the material gas is attached as an elevating means for the flow regulating plate in such a manner that one end is opened to the axis of the flow regulating plate, and the feed pipe for the material gas is projected from the film forming tank. While engaging the elevating means on the other end side of the so that it can move up and down,
The film forming apparatus by the chemical vapor deposition method according to claim 1, wherein a contact-type sealing member is interposed in a sliding portion between the material gas supply pipe and the film forming tank. 3. The film forming apparatus by the chemical vapor deposition method according to claim 1, wherein the elevating means is controlled by an NC controller.