JP2002134423A - Epitaxial growth system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of particles by completely blocking leakage of a material gas to the outside of a reaction space. SOLUTION: The epitaxial growth system for forming an epitaxial layer on the surface 10a to be grown on a semiconductor wafer 10 placed in a shield chamber 1 by supplying a material gas to the surface 10a to be grown under high temperature comprises a pair of wafer holders 11 for forming an independent space 7, by supporting a pair of semiconductor wafers 10 from the outer circumferential side, while facing respective surfaces 10a to be grown each other; nozzles 6 for introducing the material gas into the reaction space; and a gas exhaust nozzle 8 for leading out the material gas introduced into the reaction space to the outside thereof, wherein a flange part 21 is projecting from the forward end part of the gas inlet nozzle 6 toward the wafer holder side. A first groove 22, which is to be fitted idly with the flange 21, is etched in the pair of wafer holders 11 in the circumferential direction, and a second groove 23 to be fitted with the forward end of the gas exhaust nozzle 8 is etched in the outer edge. Means 15 and 16 for bringing the pair of wafer holders 11 close to each other or separating them from each other are also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epitaxial growth apparatus for forming an epitaxial layer on the surface of a semiconductor wafer, and more particularly to a shielding means for blocking a flow of a material gas from an independent reaction space to the outside.

[0002]

At present, the hydrogen carrier on a silicon substrate heated to a high _{temperature, SiCl 4, SiHCl 3, SiH} 2 Cl 2
Alternatively, an H-Si-Cl-based CVD method (Chemical vapor deposition) in which a silicon source gas (material gas) such as SiH ₄ is supplied, and a silicon single crystal is deposited and grown on the substrate through an H-Si-Cl-based reaction. It is most widely studied and applied as a silicon epitaxial growth method.

In a conventional epitaxial growth apparatus using such an epitaxial growth method, a pair of semiconductor wafers are arranged in a shield chamber with their surfaces to be opposed to each other, so that an independent reaction between the pair of semiconductor wafers is achieved. There is an apparatus provided with a pair of wafer holders forming a space, a gas supply nozzle for supplying a material gas to the reaction space, and a heater for heating the reaction space to a predetermined growth temperature. In such an epitaxial growth apparatus, a semiconductor wafer is rotated together with a wafer holder by a rotary table while heating a reaction space, and a material gas is supplied to the reaction space from a gas supply nozzle. The material gas is supplied to a growth target surface of the semiconductor wafer, and an epitaxial growth layer is formed on the surface.

[0004]

In such a conventional epitaxial growth apparatus, since the semiconductor wafer is subjected to the epitaxial growth processing in an independent reaction space, the reaction space is cut off from the outside, and the adhesion of particles to the wafer can be prevented. Excellent in point.

[0005] However, even though the reaction space is isolated from the outside, a minute gap still exists between the wafer holder and the gas supply nozzle in the upper or lower part of the reaction space. For this reason, the material gas supplied to the reaction space is
There is a case where the liquid leaks out of the reaction space through the minute gap. As a result, the leaked material gas causes the product to adhere to equipment parts outside the reaction space, such as the outer surface of the gas supply nozzle and the quartz rotary table. Such products may cause the generation of particles, and the generated particles may enter the reaction space from the gap between the wafer holder and the gas supply nozzle and adhere to the semiconductor wafer, which may cause a decrease in the quality of the epitaxial wafer. is there.

For this reason, every time the epitaxial growth process is performed, it is necessary to frequently clean the gas supply nozzle, the rotary table, and the like to remove adhered products, but this requires complicated maintenance work of the apparatus. It will be.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an epitaxial growth apparatus capable of completely preventing leakage of a material gas to the outside of a reaction space and preventing generation of particles. Purpose. Another object of the present invention is to provide an epitaxial growth apparatus capable of simplifying maintenance work of the apparatus.

[0008]

In order to achieve the above object, the invention according to claim 1 is to supply a material gas at a high temperature to a growth target surface of a semiconductor wafer installed in a shield chamber. In an epitaxial growth apparatus for forming an epitaxial layer on a growth target surface, a pair of semiconductor wafers is supported from the wafer outer peripheral side with the respective growth target surfaces facing each other, and a pair of wafer holders forming independent reaction spaces, A gas flow forming means for introducing a material gas into the reaction space, and leading the introduced material gas out of the reaction space; and the gas flow forming means and the pair of wafer holders are fitted into each other to form the gas flow. And a shielding means for closing a gap between the pair of wafer holders.

In the invention according to the first aspect, the gas flow forming means and the pair of wafer holders are fitted into each other by the shielding means to close the gap therebetween. That is, simply providing a member or the like that closes the gap between the gas flow forming means and the wafer holder still creates a gap between the closing member and the wafer holder, and between the closing member and the gas flow forming means. It is not possible to ensure a proper airtightness. In the present invention, since the gas flow forming means and the pair of wafer holders are fitted into each other by the shielding means, the gap between the two is completely closed, so that the material gas introduced into the reaction space flows out of the reaction space from the reaction space. It completely prevents leakage to the public. For this reason, it is possible to completely prevent the product from adhering to the device components such as the gas flow forming means and the rotating mechanism due to the leakage of the material gas, and to prevent the generation of particles. In addition, every time the epitaxial growth process is performed, it is not necessary to clean the device parts, and the maintenance work of the device is simplified.

[0010] Here, the reaction space in the present invention refers to a space formed by making the respective growth target surfaces of a pair of semiconductor wafers face each other, and the wafer growth target surface is also included in the reaction space.

The wafer holder according to the present invention includes a wafer holder that holds a semiconductor wafer in a horizontal state, a wafer holder that holds a semiconductor wafer in a vertical state, and a holder that holds a semiconductor wafer in an inclined state.

The shielding means in the present invention may be any as long as the pair of wafer holders and the gas flow forming means fit into each other to close the gap therebetween. For example, the gas flow forming means may be provided with an outwardly projecting portion. The gas flow forming means may be configured to fit into a groove provided on the outer edge of the wafer holder, or the protrusion may be configured to fit into a groove or the like provided in the wafer holder. Conversely, a projection may be provided on the wafer holder, and a groove in which the projection fits may be formed in the gas flow forming means.

The gas flow forming means can be composed of, for example, an introduction nozzle for introducing the material gas into the reaction space and an exhaust nozzle for extracting the material gas from the reaction space to the outside. In this case, the introduction nozzle and the wafer holder , And the exhaust nozzle and the wafer holder can be configured to fit into each other in the above-described manner. The following are specific examples of such a shielding means.

According to a second aspect of the present invention, in the epitaxial growth apparatus according to the first aspect, the shielding means includes a flange protruding toward the wafer holder near a tip end of the gas flow forming means, and the wafer holder. And a first groove which is engraved at a position facing the collar portion and receives the collar portion.

According to the second aspect of the present invention, the flange is provided on the wafer holder side near the tip of the gas flow forming means,
Since the collar portion is received in the first groove of the wafer holder, the gap between the wafer holder and the gas flow forming means for the source gas in the reaction space is completely closed, and leakage of the gas is blocked.

In the present invention, the collar portion may be provided near the tip of the gas flow forming means, and may be provided at a position separated by a certain distance from the tip of the gas flow forming means. In order to completely prevent the material gas from coming into contact with the forming means, it is preferable to provide the gas flow forming means at the tip end.

Further, the collar portion may be formed so as to protrude toward the wafer holder, and can have any shape in accordance with the shape of the gap between the wafer holder and the gas flow forming means. It can be shaped to protrude all around. Further, when the gas flow forming means is composed of a plurality of nozzles, in order to completely prevent the material gas from flowing outside the reaction space, a flange portion is provided for each nozzle, or the outer diameter of the plurality of nozzles is reduced. It is preferable to form a brim portion so as to include it.

The configuration of the groove in the present invention is not particularly limited as long as the groove can be fitted therein. When the gas flow forming means is composed of the gas introduction nozzle and the gas exhaust nozzle described above, the flange is provided both near the tip of the gas introduction nozzle and near the tip of the gas exhaust nozzle, A collar is provided only at the nozzle tip,
The gas exhaust nozzle side may be configured to close the gap between the gas exhaust nozzle and the wafer holder by other means.

According to a third aspect of the present invention, in the epitaxial growth apparatus according to the second aspect, the first groove portion includes:
The wafer holder is engraved in a circumferential direction of the wafer holder, and the collar is loosely fitted.

According to the third aspect of the present invention, since the first groove portion loosely fits the collar portion, there is a small gap between the groove portion and the collar portion in a state where the collar portion is received. It is movable in the groove. Since the first groove is formed in the circumferential direction of the wafer holder, it is possible to rotate the wafer holder in the circumferential direction. Therefore, the epitaxial growth process can be performed by rotating the wafer holder together with the semiconductor wafer while preventing leakage of the material gas to the outside of the reaction space.

In order to reliably block the flow of the material gas to the outside of the reaction space, the groove in the present invention may have a small gap such that the collar does not come into contact with the groove due to the rotation of the wafer holder. preferable.

According to a fourth aspect of the present invention, in the epitaxial growth apparatus according to the third aspect, a moving means for relatively moving the pair of wafer holders toward and away from each other is further provided.

According to the fourth aspect of the present invention, when the gas flow forming means is inserted between the wafer holders with the pair of wafer holders separated by the moving means, and then the pair of wafer holders are moved closer by the moving means, The flange of the gas flow forming means is inserted into the groove of the wafer holder.
As a result, a reaction space is formed, and the reaction space is closed by the flange and the groove. As described above, in the present invention, it is possible to simultaneously form the reaction space at the start of the epitaxial growth process and secure the hermeticity of the reaction space by the groove and the flange by the moving means.

According to a fifth aspect of the present invention, in the epitaxial growth apparatus according to the third or fourth aspect, the gas flow forming means comprises: a gas introduction nozzle for introducing a material gas into the reaction space; And a gas exhaust nozzle that guides the gas to the outside of the reaction space.The collar is provided near the tip of the gas introduction nozzle, and the pair of wafer holders further includes an outer edge portion. A second groove for loosely fitting the tip of the gas exhaust nozzle is provided.

According to the fifth aspect of the present invention, since the second groove is provided on the outer edge of the wafer holder, the tip of the gas exhaust nozzle is loosely fitted in the second groove, so that the gas exhaust is performed. The gap between the nozzle and the wafer holder is shielded. For this reason, the flow of the material gas toward the outside of the reaction space can be blocked by the wafer holder fitted in the second groove even on the gas downstream side of the reaction space, and a more complete sealing of the reaction space can be ensured. Can be.

Further, since the gas exhaust nozzle is loosely fitted in the second groove, the wafer holder can be rotated with the tip of the gas exhaust nozzle received in the second groove, so that the reaction space can be completely sealed. The epitaxial growth process can be performed while rotating the semiconductor wafer.

The second groove in the present invention also has a small gap such that the tip of the wafer holder does not come into contact with the second groove due to the rotation of the wafer holder in order to reliably block the flow of the material gas to the outside of the reaction space. It is preferable to have such a configuration.

According to a sixth aspect of the present invention, in the epitaxial growth apparatus according to the first aspect, the gas flow forming means includes: a gas introduction nozzle for introducing a material gas into the reaction space; A gas exhaust nozzle leading to the outside of the reaction space, wherein the shielding means is engraved in a circumferential direction on an outer peripheral edge of the wafer holder, and a tip of the gas introduction nozzle and a tip of the gas exhaust nozzle are provided. It is characterized by having a third groove portion for loose fitting.

In the invention according to claim 6, the gap between the wafer holder and the gas introduction nozzle is closed on the gas flow introduction side of the reaction space by fitting the tip of the gas introduction nozzle into the third groove. In addition, since the tip of the gas exhaust nozzle fits into the third groove, the gap between the wafer holder and the gas introduction nozzle is closed on the gas exhaust introduction side of the reaction space. Therefore, the reaction space is completely sealed from the outside, and the material gas is prevented from sneaking out of the reaction space and leaking.

The third groove is formed in the outer peripheral edge of the wafer holder in the circumferential direction, and the tip of the gas introduction nozzle and the tip of the gas exhaust nozzle are loosely fitted. The wafer holder can be rotated while receiving the tips of the gas introduction nozzle and the gas exhaust nozzle,
The epitaxial growth process can be performed while rotating the semiconductor wafer in a completely enclosed reaction space.

When the gas introduction nozzle is inserted close to the growth surface of the wafer, the gas introduction nozzle itself is also heated during the epitaxial growth process, so that the product adheres to the inner surface of the nozzle and particles are generated. Cause it. However, in the present invention, since the reaction space is shielded from the outside by freely fitting the tip of the gas introduction nozzle into the third groove formed in the outer peripheral edge of the wafer holder, the gas introduction nozzle is connected to the wafer in the reaction space. There is no need to approach. For this reason, the material gas reaches the growth target surface of the wafer after being preheated by the wafer holder, and the material growth gas does not cool the wafer growth target surface, thereby preventing quality deterioration of the epitaxial growth layer due to cooling.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a schematic configuration diagram of the epitaxial growth apparatus according to the first embodiment. The epitaxial growth apparatus of the present embodiment uses a vertical type chamber 1 and two
An epitaxial layer is formed on the growth target surface 10a in a state where the 0-mm silicon wafers 10 are vertically set.

The epitaxial growth apparatus of the present embodiment
As shown in FIG. 4, a pair of wafer holders 11 for holding each of a pair of two silicon wafers 10 so that respective growth target surfaces 10a face each other, and a pair of wafer holders for supporting each of the pair of wafer holders 11 from the outer periphery thereof. Rotary table 12
A gas introduction nozzle 6 for injecting a silicon source gas as a material gas between the growth target surfaces 10a of the pair of wafers 10 from above, a gas supply pipe 5 for introducing a silicon source gas to the gas introduction nozzle 6, A gas exhaust nozzle 8 for sucking and exhausting the silicon source gas supplied between the growth target surfaces 10a to the outside of the apparatus, and two resistance heaters 9 as heating sources for heating each silicon wafer 10 from the back side. And a ball screw mechanism as moving means of the present invention for moving the pair of rotary tables 12 toward and away from each other.

FIG. 1 shows a wafer holder 11, five gas introduction nozzles 6, a gas exhaust nozzle 8, and a portion of a silicon wafer 10 held by the wafer holder 11 in the epitaxial growth apparatus of the present embodiment. FIG. 3 is an enlarged perspective view of the device as viewed from the right side. FIG. 2A is an enlarged cross-sectional view taken along the line AA in FIG.

As shown in FIGS. 1 and 2A, each of the pair of wafer holders 11 has an annular shape, and holds the peripheral edge of the wafer 10 at each inner edge. Further, a plurality of quartz springs are provided on the inner edge portion of the wafer holder 11, and the elastic force of the quartz spring urges the wafer 10 so that the wafer 1
0 does not easily fall off the wafer holder 11.

The outer peripheral portion of the wafer holder 11 is releasably held by the periphery of the opening of the rotary table 12. That is, a pair of silicon wafers 10 are respectively placed on the respective growth target surfaces 10a so as to cover the openings of the turntable 12.
Are vertically fixed by the wafer holder 11 so as to face each other. As described above, in the present embodiment, in the chamber 1, the rotating table 12, the wafer holder 11, and the pair of wafers 10
A reaction space 7 independent from the surroundings is formed between the 0 growth target surfaces 10a. Here, the reaction space 7 refers to a space formed by making the respective growth target surfaces 10a of the pair of wafers 10 face each other.
a is also included in the reaction space.

On the opposing surfaces of the pair of wafer holders 11, a first groove portion 22 for loosely fitting a flange portion 21 of a wafer 10 introduction nozzle described later is formed in the circumferential direction. Also,
A second groove portion 23 in which a distal end portion of a gas exhaust nozzle 8 described later is loosely fitted to an outer edge portion of the wafer holder 11 in a circumferential direction.
Is engraved.

The outer edge of each rotary table 12 is in contact with the outer peripheral surface of the bearing 3a at one location at the top apex, and the outer peripheral surface of the bearing 3b provided at two locations on the front and rear sides of the lower part of the apparatus. . All three bearings are configured to be rotatable. FIG. 4 shows a bearing 3b provided on the front side of the apparatus.
Only a bearing is provided at the same height as the bearing 3a on the rear surface side of the apparatus, but this is omitted. Of the lower bearings, bearings on the rear side of the device (not shown)
Is rotated about a horizontal axis by the driving of an electric motor (not shown), and the rotary table 12 is rotated about the horizontal axis, whereby the silicon wafer 10 held in the vertical plane together with the wafer holder 11 is also rotated about the horizontal axis. Rotate.

Each of the rotary tables 12 can be moved in the left-right direction in FIG. 4 by a ball screw mechanism, and the pair of rotary tables 12 approach and move away from each other. That is, the nut 1 is provided on the outer edge of each turntable 12.
6 is circumscribed, and the nut 16 is screwed to a threaded rod 15 extending in the horizontal direction. The nut 1 is rotated by rotating the screw rod 15 by the electric motor 17a.
6 moves left and right, and as a result, the rotary table 12 and the wafer holder 11 held by the rotary table 12
It moves left and right by 0. Therefore, the pair of rotary tables 12, the pair of wafer holders 11, and the pair of wafers 10
Can be approached and separated from each other. The ball screw mechanism (the nut 16 and the screw rod 15) and the electric motor 17a constitute the moving means of the present invention.

FIG. 3A is a front view showing the configuration of the gas introduction nozzle 6 used in the epitaxial growth apparatus of the present embodiment, and is a perspective view from the side of the apparatus in FIG. FIG.
3B is a perspective view of the gas introduction nozzle 6, and FIG. 3C is a cross-sectional view taken along the line BB in FIG. 3A. FIG.
As shown in the figure, the upper end of each gas introduction nozzle 6 is connected to a gas supply pipe 5 penetrated from the upper part of the chamber 1 to the inside, and the lower part of each gas introduction nozzle 6 is inserted into the reaction space 7. Then, a silicon source gas is injected into the reaction space 7. As shown in FIG. 3B, the cross-sectional shape of the injection port 6a of each gas introduction nozzle is substantially rectangular.

As shown in FIGS. 1, 3 (a) and 3 (b), five gas introduction nozzles 6 are arranged in parallel so as to surround a half circumference of one side of the wafer 10, and the shape of the tip of each nozzle is Are arc-shaped along the outer circumferences of the wafer holder 11 and the wafer 10, respectively. That is, the entire distal end portion of the five gas introduction nozzles 6 arranged in parallel has an arc shape of a substantially semicircular upper side concentric with the outer periphery of the wafer 10, and the half circumference of one side of the wafer 10 is surrounded. This is because the flow of the silicon source gas injected from the gas introduction nozzle 6 is not disturbed and the wafer 1
This is for leading to the zero growth target surface 10a.

As shown in FIG. 3 (c), the gas introduction nozzle 6 has a gradually tapered shape from the upper part to the lower part. The lower part from the lower end of the tapered portion has a tapered shape that expands so that the cross-sectional area of the flow path gradually increases toward the injection port, and the width of the injection port is the distance between the pair of wafer holders 11 and the pair of wafer growth target surfaces. It is almost equal to the interval of 10a. This is to prevent a sudden change in the gas flow path cross-sectional area from occurring and to prevent the gas flow of the silicon source gas injected from the gas introduction nozzle 6 from being disturbed.

The tip of each gas introduction nozzle 6 is
The flange portions 2 are provided outward on both sides (in a direction perpendicular to the wafer growth target surface 10a) so as to close the gas flow path of the reaction space 7 formed by the pair of wafers 10 and the pair of wafer holders 11.
One is overhanging. The flange portion 21 extends in an arc shape of a substantially semicircular upper portion according to the shape of the tip of the five gas introduction nozzles 6 arranged in parallel.

When the epitaxial growth process is performed, as shown in FIG. 2A, the flange portion 21 is loosely fitted in the first groove portion 22 of the wafer holder 11 with the pair of wafers 10 facing each other and held by the wafer holder 11. Is done. In this state, there is a minute gap between the flange 21 and the first groove 22, but since the gap is bent, it becomes difficult for the silicon source gas in the reaction space 7 to pass through the gap. The reaction space 7 is shielded from the outside by the flange portion 21 and the first groove portion 22 into which the collar portion 21 is loosely fitted, so that the silicon source gas is prevented from flowing outside the reaction space 7. As described above, when the epitaxial growth process is performed, the reaction space 7 is shielded from the outside on the gas upstream side.

The gas exhaust nozzle 8 is for sucking the silicon source gas in the reaction space 7 and exhausting it outside the apparatus. The tip opening of the gas exhaust nozzle 8 is
0 so as to be connected in an arc shape at the tip of the gas introduction nozzle between the respective growth target surfaces 10a, and extends in a remaining substantially semicircular arc shape corresponding to the outer peripheral shape of the wafer 10. For this reason, the gas introduction nozzle 6 and the gas exhaust nozzle 8 face each other at both ends.

The gas exhaust nozzle 8 can be moved up and down by an electric motor (not shown) outside the apparatus. When the epitaxial growth process is performed, the gas exhaust nozzle 8 moves upward, and the tip of the nozzle is engraved on the outer peripheral surface of the wafer holder 11. Second
The groove 23 is loosely fitted. In this state,
Although a minute gap exists between the gas exhaust nozzle 8 and the second groove 23, the gap is bent, so that it becomes difficult for the silicon source gas in the reaction space 7 to pass through the gap, and the reaction space 7 Of the silicon source gas is prevented from flowing outside. As described above, when the epitaxial growth process is performed, the reaction space 7 is shielded from the outside even on the gas downstream side.

The flange 21 is loosely fitted in the first groove 22, and the tip of the gas exhaust nozzle 8 is similarly fitted in the second groove 2.
3 is loosely fitted to the wafer holder 1
It is possible to execute the epitaxial growth process while rotating the wafer while holding it at 1.

As shown in FIG. 4, inside the heater cover 9a, the resistance heater 9 is supported by a support member 18. The heater 9 has a second ball screw mechanism including a second screw rod 19 extending in the horizontal direction and rotatable about an axis, and a second nut 20 screwed to the screw rod 19, and a second screw rod 19.
And an electric motor for rotating the shaft of the
a can be moved in the left-right direction in FIG.
The heating temperature of the wafer 10 is adjusted by changing the relative distance between the heater 9 and the wafer 10.

Next, the silicon wafer 1 using the epitaxial growth apparatus of the present embodiment configured as described above is used.
The zero epitaxial growth process will be described. First,
The silicon wafer 10 that has undergone various manufacturing processes such as removal of a surface oxide film, polishing, and final cleaning is transferred into the chamber 1 by a robot hand or the like (not shown). At this time, the heater cover 9a and the heater Reference numeral 9 denotes a position farthest from the wafer 10, and the inside of the chamber 1 is maintained at a preheating temperature (about 300 to 800 ° C.).

FIG. 2B is an explanatory view showing the positions of the wafer 10, the wafer holder 11, the rotary table 12, and the gas exhaust nozzle 8 when the wafer 10 is transferred into the chamber 1. As shown in FIG. 2B, when the wafer 10 is loaded, a pair of the wafer holder 11 and the rotary table 12 are provided.
Is located at a position where the relative distance is longest by the ball screw mechanism (hereinafter, referred to as “loading position”). In this state, the robot hand outside the chamber 1
Is loaded into the loading position and fitted on the inner edge of the wafer holder 11. Thus, the loaded wafer 10 is held by the wafer holder 11. At this time, the exhaust nozzle has been moved downward.

Next, the pair of rotary tables 12 are moved by the ball screw mechanism to approach each other. Thus, the pair of wafer holders 1 holding the wafer 10 is held.
When the relative distance gradually becomes narrower and approaches a position where the relative distance is shortest (hereinafter, referred to as a “process position”), the movement of 1 is stopped. At this time, a pair of rotary tables 1
2, the positions of the pair of wafer holders 11, the pair of wafers 10, and the gas exhaust nozzle 8 are as shown in FIG.

As shown in FIG. 2A, at the process position, the relative distance between the pair of wafers 10 and the pair of wafer holders 11 is shorter than the width of the flange 21 but the wafer holder 1
In FIG. 1, the first groove portion 22 is engraved in the circumferential direction at a position corresponding to the collar portion 21, so that the collar portion 21 is loosely fitted in the first groove portion 22. At this time, the exhaust nozzle is moved upward by the driving of the electric motor (not shown), and the tip of the exhaust nozzle is loosely fitted in the second groove 23 of the wafer holder 11.

Then, at this process position, the injection of a silicon source gas such as SiCl ₄ , SiHCl ₂ , SiH ₂ Cl ₂ , SiH ₄ from the gas introduction nozzle 6 into the reaction space 7 including the wafer is started. Next, the heater cover 9a
Gradually approaches the wafer 10 and is maintained at the closest position. Further, the rotating table 12 is rotated together with the wafer 10 by the rotating mechanism. Thereby, the silicon wafer 1
0 gradually rises to a reaction temperature (about 900 to 1100 ° C.), and an epitaxial layer is gradually formed on the rotating pair of wafer growth target surfaces 10a.

After the epitaxial layer is formed on the wafer 10, the heater cover 9a is moved away from the wafer 10 to lower the heating temperature of the silicon wafer 10. Then, the pair of rotary tables 12 are moved away from each other by the ball screw mechanism to return the pair of wafers 10 and the pair of wafer holders 11 to the loading position. Next, the wafer 10 is removed from the wafer holder 11 by a robot hand outside the chamber 1 and is discharged outside the chamber 1. Thus, a series of epitaxial growth processes is completed.

As described above, in the epitaxial growth apparatus of this embodiment, when the epitaxial growth process is performed,
The upper opening of the reaction space 7 is shielded by the first groove 22 formed in the wafer holder 11 and the flange 21 of the gas introduction nozzle 6 loosely fitted in the first groove 22, and the silicon source supplied to the reaction space 7 Gas is prevented from flowing out of the reaction space 7 from the gas upstream side, and the wafer holder 11
The reaction space 7 is formed by a second groove 23 engraved on the outer peripheral side surface and a tip end of the gas exhaust nozzle 8 loosely fitted in the second groove 23.
Of the reaction space 7 is prevented from leaking from the gas downstream side to the outside of the reaction space 7. For this reason, the rotary table 1 outside the reaction space 7
Thus, it is possible to prevent the generation of particles before the silicon source gas comes into contact with the device components such as 2. Further, since particles do not adhere to the device components outside the reaction space 7, it is not necessary to clean the device components every time the epitaxial growth process is performed, and the number of maintenance of the device is reduced.

In the epitaxial growth apparatus according to this embodiment, the flange 21 of the gas introduction nozzle 6 is loosely fitted in the first groove 22 during the epitaxial growth process, and the tip of the gas exhaust nozzle 8 is similarly fitted to the second groove 23. The reaction space 7 is shielded from the outside so that the wafer 1
By rotating 0, the epitaxial growth process can be performed. Therefore, it is possible to form a uniform epitaxial layer on the wafer 10 while preventing generation of particles.

In the epitaxial growth apparatus of the present embodiment, the flange 21 is formed at the tip of the gas introduction nozzle 6, but as shown in FIG. The collar 21 may be formed.

(Second Embodiment) Next, an epitaxial growth apparatus according to a second embodiment will be described. In the epitaxial growth apparatus of the second embodiment, only the gas introduction nozzle 6 and the wafer holder 11 are different from the apparatus of the first embodiment. FIG. 7 is an enlarged cross-sectional view showing the states of the wafer 10, the wafer holder 11, the gas introduction nozzle 6, and the gas exhaust nozzle 8 when performing the epitaxial growth process in the epitaxial growth apparatus of the second embodiment. Other configurations are first
The description is omitted because it is the same as the epitaxial growth apparatus of the embodiment.

In the epitaxial growth apparatus of the second embodiment, as shown in FIG. 7, a third groove 25 is formed on the outer peripheral side surface of the wafer holder in the circumferential direction. The gas introduction nozzle 6 is bent left and right at a position above the wafer holder and extends in the horizontal direction, and bent downward at a position above the third groove 25 so that the nozzle tip is loosely fitted in the third groove. . Further, the gas exhaust nozzle 8 is loosely fitted into the third groove 25 from below the wafer holder 11 similarly to the apparatus of the first embodiment. The gas introducing nozzle 6 can be moved vertically by a moving mechanism (not shown). The gas introducing nozzle 6 is at an upper position when the wafer 10 is transferred, moves downward when the epitaxial growth process is performed, and the tip of the nozzle is moved to the third groove 25. It is designed to fit loosely. The gas exhaust nozzle 8 can also be moved up and down as in the first embodiment, and is at a lower position when the wafer 10 is transferred, moves upward during the epitaxial growth process, and the tip of the nozzle is loosely fitted into the third groove 25. It is supposed to.

FIG. 5A is an enlarged view showing the state of both ends of the gas introduction nozzle 6 and the gas exhaust nozzle 8 in the epitaxial growth apparatus of the second embodiment. As shown in FIG. 5A, step portions 24a and 24b are provided at both ends of the gas introduction nozzle 6 and the gas exhaust nozzle 8, respectively.
Both step portions 24a and 24b are fitted with a minute gap. Since the gap is bent due to the step portions 24a and 24b being opposed to each other, it is difficult for the material gas to pass through the gap, so that the reaction space is closed. Therefore, leakage of the material gas from between the gas introduction nozzle and the gas exhaust nozzle is prevented.
In this embodiment, steps are provided at both ends of the gas introduction nozzle and the gas exhaust nozzle. However, as shown in FIG. 5B, both ends are formed in a tapered shape and are opposed to each other. You may.

As described above, in the epitaxial growth apparatus of this embodiment, when the epitaxial growth process is performed,
The upper opening of the reaction space 7 is shielded by a gas introduction nozzle loosely fitted in a third groove formed in the outer peripheral side surface of the wafer holder 11, and the silicon source gas supplied to the reaction space 7 is supplied from the gas upstream side to the reaction space 7. It prevents leakage to the outside. Further, the lower opening of the reaction space 7 is shielded by the tip of the gas exhaust nozzle loosely fitted in the third groove portion, so that the silicon source gas in the reaction space 7 is prevented from leaking from the gas downstream side to the outside of the reaction space 7. Therefore, the silicon source gas does not come into contact with the device components such as the rotary table 12 outside the reaction space 7, and it is possible to prevent the generation of particles. Further, since particles do not adhere to the device components outside the reaction space 7, it is not necessary to clean the device components every time the epitaxial growth process is performed, and the number of maintenance of the device is reduced.

Further, in this embodiment, since the gas introduction nozzle 6 is located at a position before the wafer holder 11 and is not inserted into the reaction space 7, the silicon source gas is supplied to the wafer holder 1.
Surface 1 to be grown of wafer 10 in a state preheated by
0a, and the wafer growth target surface 10a is not cooled by the silicon source gas, so that deterioration of the quality of the epitaxial growth layer due to cooling can be prevented.

In the epitaxial growth apparatuses of the first and second embodiments, the large-diameter wafer is subjected to the epitaxial growth processing. However, the present invention is not limited to this, and the epitaxial growth processing may be performed for the wafer having a diameter of 400 mm or less. It is optional to design.

In the first and second embodiments, the present invention is applied to an apparatus that performs an epitaxial growth process while holding a pair of wafers vertically.
The present invention can be applied to any apparatus having an independent reaction space inside the chamber 1 and performing an epitaxial growth process in a state where a pair of wafers are horizontally or inclined in the reaction space.

[0065]

As described above, according to the first aspect of the present invention, since the gas flow forming means and the pair of wafer holders fit into each other by the shielding means to close the gap therebetween, the material gas leaks. It is possible to completely prevent the products from adhering to the device parts such as the gas flow forming means and the rotating mechanism, and to prevent the generation of particles. In addition, it is not necessary to clean the device parts every time the epitaxial growth process is performed, so that the maintenance work of the device is simplified.

In particular, in the invention according to the second aspect, the collar is formed at a position protruding from the wafer holder in the vicinity of the front end of the gas flow forming means and at a position opposite to the flange of the wafer holder.
Since it has the first groove for receiving the collar portion, the gap between the wafer holder and the gas flow forming means for the material gas in the reaction space is completely closed, and the gas leakage is prevented.

In the invention according to claim 3, the first groove portion is
Since it is engraved in the circumferential direction of the wafer holder and the flange portion is loosely fitted, the epitaxial growth process can be performed while rotating the semiconductor wafer while blocking the leakage of the material gas to the outside of the reaction space. As a result, There is an effect that a uniform epitaxial growth layer can be formed while preventing generation of particles.

According to the fourth aspect of the present invention, there is provided a moving means for relatively moving the pair of wafer holders toward and away from each other.
This has the effect of simultaneously forming the reaction space at the start of the epitaxial growth process and ensuring the hermeticity of the reaction space by the groove and the flange.

According to a fifth aspect of the present invention, the collar portion is provided near the tip of the gas introduction nozzle, and the pair of wafer holders has the second edge for loosely fitting the tip of the gas exhaust nozzle to the outer edge thereof. The groove is cut out, so that the leakage of the material gas to the outside of the reaction space can be completely blocked not only on the gas upstream side of the reaction space but also on the downstream side of the gas in the reaction space, so that the reaction space is more completely sealed. The effect that the property can be secured is produced.
In addition, the epitaxial growth process can be performed while rotating the semiconductor wafer in the reaction space that is completely sealed in this way, and there is an effect that a uniform epitaxial growth layer can be formed while preventing generation of particles.

According to a sixth aspect of the present invention, in the third aspect, the shielding means is engraved on the outer peripheral edge of the wafer holder in the circumferential direction, and the tip of the gas introduction nozzle and the tip of the gas exhaust nozzle are loosely fitted.
Since the groove portion is provided, leakage of the material gas to the outside of the reaction space on the gas upstream side and the gas downstream side of the reaction space is shut off, so that a more complete airtightness of the reaction space can be secured. In addition, the epitaxial growth process can be performed while rotating the semiconductor wafer in a completely enclosed reaction space, and while preventing generation of particles,
There is an effect that a uniform epitaxial growth layer can be formed.

Further, according to the present invention, since it is not necessary to bring the gas introduction nozzle close to the wafer in the reaction space, the quality of the epitaxially grown layer can be prevented from being deteriorated by cooling, and the effect of forming a high quality epitaxially grown layer can be obtained.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a wafer holder, a wafer, a rotary table, and a gas introduction nozzle in an epitaxial growth apparatus of a first embodiment.

FIG. 2A is an enlarged cross-sectional view taken along the line AA of FIG. 1 and shows states of a wafer, a wafer holder, a gas introduction nozzle, and a gas exhaust nozzle when an epitaxial growth process is performed in the epitaxial growth apparatus of the first embodiment. Yes, Figure 2
(B) is an enlarged sectional view showing the state of a wafer, a wafer holder, a gas introduction nozzle, and a gas exhaust nozzle during transfer.

FIG. 3A is a front view showing a configuration of a gas introduction nozzle used in the epitaxial growth apparatus of the first embodiment, and FIG. 3B is a perspective view of the gas introduction nozzle 6, and FIG. FIG. 3C is a sectional view taken along the line BB in FIG.

FIG. 4 is a perspective view showing the overall configuration of the epitaxial growth apparatus according to the first embodiment.

FIG. 5A is an enlarged view showing a state of both ends of a gas introduction nozzle and a gas exhaust nozzle in the epitaxial growth apparatus of the second embodiment, and FIG. 5B is an enlarged view showing another aspect. FIG.

FIG. 6 is an enlarged cross-sectional view showing another aspect of the gas introduction nozzle having a flange used in the epitaxial growth apparatus of the first embodiment.

FIG. 7 is an enlarged sectional view showing a state of a wafer, a wafer holder, a gas introduction nozzle, and a gas exhaust nozzle when an epitaxial growth process is performed in the epitaxial growth apparatus of the second embodiment.

[Explanation of symbols]

 1: chamber 3a, 3b: bearing 5: gas supply pipe 6: gas introduction nozzle 6a: injection port 7: reaction space 8: gas exhaust nozzle 9: resistance heater 9a: heater cover 10: silicon wafer 10a: growth target surface 11 : Wafer holder 12: Rotary table 15: Screw rod 16: Nut 17 a: Electric motor for moving holder 17 b: Electric motor for moving heater 18: Support member 19: Second screw rod 20: Second nut 21: Collar 22: First Groove 23: Second groove 24a, 24b: Step 25: Third groove

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masato Imai 555-1 Nakanoya, Annaka-shi, Gunma Inside the Super Silicon Research Laboratories Co., Ltd. (72) Inventor Shinji Nakahara 1-555, Nakanoya, Annaka-shi, Gunma Inside the Super Silicon Research Laboratories (72) Inventor Shinichi Igan 370 Notsubo, Ichitsubo, Nakahara-ku, Kawasaki City, Kanagawa Prefecture F-term (reference) 4Y030 Chemical Co., Ltd. AB02 AC01 AC03 AD13 AD14 AD15 AF03 BB15 DP11 EC07 EM03 EM10

Claims (6)

[Claims] 1. An epitaxial growth apparatus for forming an epitaxial layer on a growth target surface by supplying a material gas at a high temperature to a growth target surface of a semiconductor wafer installed in a shield chamber, comprising: A pair of wafer holders that form an independent reaction space by supporting the growth target surface from the wafer outer peripheral side in an opposed state, introducing a material gas into the reaction space, and disposing the introduced material gas outside the reaction space Gas flow forming means for guiding the gas flow forming means and the pair of wafer holders to each other, and shielding means for closing a gap between the gas flow forming means and the pair of wafer holders. Characteristic epitaxial growth equipment. 2. The method according to claim 1, wherein the shielding means is engraved at a position protruding toward the wafer holder near a tip end of the gas flow forming means, and at a position facing the collar part of the wafer holder.
An epitaxial growth apparatus comprising: a first groove configured to receive the collar. 3. The epitaxial growth apparatus according to claim 2, wherein the first groove is formed in a circumferential direction of the wafer holder, and the flange is loosely fitted. 4. The epitaxial growth apparatus according to claim 3, further comprising moving means for relatively moving the pair of wafer holders toward and away from each other. 5. The gas flow forming means includes a gas introduction nozzle for introducing a material gas into the reaction space, and a gas exhaust nozzle for leading the introduced material gas out of the reaction space. The collar portion is provided near a tip portion of the gas introduction nozzle. The pair of wafer holders is further provided with a second groove portion for loosely fitting the tip portion of the gas exhaust nozzle at an outer edge thereof. The epitaxial growth apparatus according to claim 3, wherein the apparatus is formed. 6. The gas flow forming means includes a gas introduction nozzle for introducing a material gas into the reaction space, and a gas exhaust nozzle for leading the introduced material gas to the outside of the reaction space. The shielding means is provided on the outer peripheral edge of the wafer holder in a circumferential direction, and has a third groove for loosely fitting the tip of the gas introduction nozzle and the tip of the gas exhaust nozzle. The epitaxial growth apparatus according to claim 1, wherein