JP2006222228A - Chemical vapor deposition equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a thin film uniformly on the surface of a semiconductor wafer by reducing the amount of reaction gas used, and to enhance maintainability of the equipment by reducing consumption of the rotational mechanism of a susceptor. <P>SOLUTION: The chemical vapor deposition equipment 1 comprises a reaction chamber 2 into which reaction gas can be introduced, a susceptor 4 capable of fixing a semiconductor wafer 3 to the lower surface side by a supporting fixture 12 and arranged in the reaction chamber 2 while being secured to a supporting leg 13, a rotational mechanism 5 for rotating the susceptor 4 about its axis through the supporting leg 13, a heater 6 for heating the semiconductor wafer 3 fixed to the susceptor 4, and a nozzle 7 for blowing the reaction gas from a nozzle pipe 7a to the surface 3a of the semiconductor wafer 3 wherein the nozzle pipe 7a has the distal end side projecting into the reaction chamber 2 and a distal end opening 7d facing the downward surface 3a of the semiconductor wafer 3 and position E from the center C of the semiconductor wafer 3 in the diametral direction is set in the intermediate portion of the center C and the outer circumferential edge. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a chemical vapor deposition apparatus for forming a thin film on the surface of a semiconductor wafer disposed in a reaction chamber by reaction of a reaction gas.

Conventionally, as this type of chemical vapor deposition apparatus, a semiconductor that includes a susceptor that is rotated by a rotating mechanism in a reaction chamber and that is mounted on the susceptor and rotates a reaction gas ejected from a nozzle opened in the reaction chamber. It is known that a thin film is formed on the surface of the semiconductor wafer by flowing in parallel to the surface of the semiconductor wafer from one end side of the outer peripheral edge of the wafer toward the other end side facing in the diametrical direction ( For example, see Patent Document 1, Patent Document 2, and Patent Document 3.)
In addition, a susceptor that is horizontally rotated by a rotation mechanism is provided in the lower part of the reaction chamber, and a plurality of semiconductor wafers that are mounted on the susceptor and rotate in the circumferential direction of the susceptor are opened at the upper part of the reaction chamber. A reaction gas ejected from a plurality of nozzles is made to flow in a direction perpendicular to the surface of the semiconductor wafer to form a thin film on the surface of the semiconductor wafer (see, for example, Patent Document 4). ).
JP 2001-262353 A Japanese Patent Laid-Open No. 2003-10063 JP 2003-166059 A JP 2004-172386 A

However, in the former in the conventional chemical vapor deposition apparatus, the reaction gas ejected from the nozzle does not contact the surface of the semiconductor wafer with a sufficient biasing pressure, and from one end side of the outer peripheral edge of the semiconductor wafer. Since it flows quickly to the other end side, it is used as a device for chemical vapor deposition (CVD growth) of wide band gap semiconductors such as SiC and GaN in particular, and is uniform on a large area semiconductor wafer of 3 inches or more. In the case of growing a thin film, for example, the required purpose can be achieved unless a huge reactive gas (carrier gas such as source gas, hydrogen, or rare gas) of about 100 L / min is flowed per substrate. Not for this. There is a problem that the consumption of the reaction gas increases. In addition, since the rotating mechanism for rotating the susceptor on which the semiconductor wafer is mounted is placed in an area heated to 1500 ° C. or more by the heater, the sliding portions of the components such as the rotating shaft in the rotating mechanism are worn out. The maintenance and inspection of these components must be performed frequently, and there is a problem that the maintainability of the apparatus is inferior.
On the other hand, in the latter case of the conventional chemical vapor deposition apparatus, the reaction gas is directed to the entire reaction chamber from the nozzle at the top of the reaction chamber toward the semiconductor wafer placed at a position away from the nozzle. Because a large amount of reaction gas is consumed as in the case of the former chemical vapor deposition apparatus, and the sliding part such as the rotating shaft in the rotating mechanism of the susceptor is located in the vicinity of the heating area by the heater. As with the above, there are problems such as poor maintainability of the apparatus.

The present invention has been made in view of the above circumstances, and provides a chemical vapor deposition apparatus capable of reducing the amount of reaction gas used and forming a thin film uniformly on the surface of a semiconductor wafer. Objective.
Another object of the present invention is to provide a chemical vapor deposition apparatus capable of reducing the wear of a rotating mechanism of a susceptor on which a semiconductor wafer is mounted and improving the maintainability of the apparatus.

The present invention is characterized by the following points in order to solve the above problems.
That is, the chemical vapor deposition apparatus according to claim 1 includes a reaction chamber into which a reaction gas can be introduced, a susceptor on which a semiconductor wafer can be mounted on the lower surface side, and rotatably disposed in the reaction chamber; In a chemical vapor deposition apparatus comprising: a rotation mechanism that rotates a susceptor about its axis; a heater that heats a semiconductor wafer mounted on the susceptor; and a nozzle that blows a reaction gas onto the surface of the semiconductor wafer.
The nozzle is provided with the tip side protruding into the reaction chamber, the tip opening is opposed to the surface facing the lower side of the semiconductor wafer, and the center and the outer peripheral edge from the center in the diameter direction of the semiconductor wafer. It is characterized by being arranged within the range up to the middle part.

  The chemical vapor deposition apparatus according to claim 2 is the chemical vapor deposition apparatus according to claim 1, wherein the heater is disposed so as to heat an upper portion of the reaction chamber, and the susceptor is disposed below the reaction chamber. It is supported by the upper part of the support leg rotated by the said rotation mechanism, and is arrange | positioned at the upper part of the said reaction chamber, It is characterized by the above-mentioned.

  The chemical vapor deposition apparatus according to claim 3 is the chemical vapor deposition apparatus according to claim 1 or 2, wherein the nozzle has a tip opening at an intermediate portion between the center and the outer peripheral edge in the diameter direction of the semiconductor wafer. It is characterized by being arranged.

  The chemical vapor deposition apparatus according to claim 4 is the chemical vapor deposition apparatus according to any one of claims 1 to 3, wherein the susceptor makes the center of the semiconductor wafer coincide with the central axis of the reaction chamber. It is characterized by being able to rotate around the central axis of the reaction chamber.

The present invention has the following excellent effects.
That is, according to the chemical vapor deposition apparatus of the first aspect, the reactive gas can be blown toward the surface facing the lower side of the semiconductor wafer in an appropriate predetermined region in the diameter direction of the semiconductor wafer. The surface of the semiconductor wafer is effectively energized and brought into contact, and a thin film having a predetermined thickness can be efficiently formed even with a small amount of reaction gas, whereby the amount of reaction gas used can be reduced.

  According to the chemical vapor deposition apparatus of the second aspect, the rotating mechanism for rotating the susceptor that supports the semiconductor wafer is disposed below the upper part of the reaction chamber heated by the heater via the support legs. Therefore, even if there are sliding parts or the like in the constituent members of the rotating mechanism, they can be prevented from being exposed to high heat and worn out, and their service life can be extended to improve the maintainability of the apparatus. Can do.

  According to the chemical vapor deposition apparatus of the third aspect, the reactive gas spraying position with respect to the surface of the semiconductor wafer rotating around the center is optimally set, so that a thin film is formed in the diameter direction of the surface of the semiconductor wafer. Can be performed as uniformly as possible.

  According to the chemical vapor deposition apparatus of the fourth aspect, since the semiconductor wafer rotates about its central axis in the reaction chamber, the surface of the semiconductor wafer is heated uniformly by the heater, resulting in temperature unevenness. In this respect, the thin film can be satisfactorily formed on the surface of the semiconductor wafer.

Hereinafter, a chemical vapor deposition apparatus according to a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a chemical vapor deposition apparatus according to a first embodiment of the present invention. This chemical vapor deposition apparatus 1 is capable of mounting a reaction chamber 2 and a semiconductor wafer 3, a susceptor 4 rotatably provided in the reaction chamber 2, a rotating mechanism 5 for rotating the susceptor 4, A heater 6 for heating the semiconductor wafer 3 mounted on the susceptor 4 and a nozzle 7 for spraying a reaction gas onto the surface 3a of the semiconductor wafer 3 are provided.
The reaction chamber 2 has a cylindrical (cylindrical) body portion 8 made of quartz, and a circularly fixed removably with an O-ring 9 interposed between an annular flange 8a on the upper portion of the body portion 8. A plate-like flange 10 is provided, and a lower annular flange 8b is fixed to the upper surface of the wall portion 11 of the load lock chamber in an airtight manner through an O-ring 9 so that the direction of the central axis S1 is vertical. It is installed towards. At the center of the flange 10 (position of the central axis S1), an exhaust port 10a penetrating vertically is provided.

The susceptor 4 is made of a carbon disk-like member having a flange portion 4a on the outer periphery of the upper portion, and is arranged in the internal space 2a of the upper portion of the reaction chamber 2 with its axis line coincident with the central axis S1 of the reaction chamber 2. Yes. On the lower surface of the susceptor 4, the semiconductor wafer 3 is supported with a plurality of hook-shaped outer peripheral edges with the surface 3 a facing downward and the center C aligned with the central axis S 1 of the reaction chamber 2. It is supported by the tool 12 and can be attached and detached. On the outer peripheral side of the flange portion 4a, a plurality of exhaust ports 4b are provided penetrating in a direction parallel to the central axis S1 with a predetermined interval in the circumferential direction.
Next, in the internal space 2 a of the reaction chamber 2, carbon cylindrical (tubular) support legs 13 are arranged with their axes aligned with the central axis S 1 of the reaction chamber 2. At the upper end, the susceptor 4 is fixed horizontally (perpendicular to the central axis S1) via the flange portion 4a. And the lower end part of the said support leg 13 is fixed to the upper surface of the cyclic | annular support ring 14 arrange | positioned horizontally, and this support ring 14 is joined to the lower surface of the wall part 11 of the said load lock chamber via the O-ring 9. And supported on the upper surface of a flat partition wall (gate valve) 16 that hermetically closes the opening portion 11a of the wall portion 11 via a bearing 15, and is rotatably provided about the central axis S1. .

The bearing 15 has an annular groove 14a having a V-shaped cross section formed at the lower surface of the support ring 14 so as to coincide with the central axis S1, and the central axis S1 at the upper surface of the partition wall 16. An annular groove 16a having a V-shaped cross section and a plurality of balls 15a that are fitted over the annular grooves 14a and 16a and arranged at intervals in the circumferential direction thereof. Instead of the bearing 15, a normal ball bearing may be mounted between the support ring and the partition wall 16. The ball 15a is made of carbon, and its surface is coated with TaC so as not to be worn.
The rotation mechanism 5 rotates around an axis parallel to the central axis S1 supported by the partition 16 and an internal gear 17 formed inside the support ring 14 so as to coincide with the center axis S1. A rotating shaft 18, a pinion gear 19 attached to the upper end portion of the rotating shaft 18 and meshed with the internal gear 17, and driving means (not shown) such as an electric motor for rotating the rotating shaft 18. And the support means 13 is rotated around the central axis S1 via the rotary shaft 18, the pinion gear 19 and the internal gear 17 by the operation of the driving means, and the susceptor 4 (semiconductor wafer 3) is moved to the central axis S1. It is designed to rotate around.

The heater 6 is formed of a high frequency induction coil having a predetermined length (height) in the direction of the central axis S1, for example, and the center of the susceptor 4 in the longitudinal direction at the height position in the direction of the central axis S1. Is placed so as to surround the outer periphery of the reaction chamber 2, and the semiconductor wafer 3 mounted on the susceptor 4 is heated to, for example, about 1500 to 1800 ° C. by high frequency induction heating. It is like that.
The nozzle 7 is composed of a cylindrical nozzle tube 7a and a jacket tube 7c provided concentrically with an annular space 7b on the outer side thereof, and the partition wall 16 is arranged with the axis S2 in the direction along the central axis S1. The upper end portion (tip portion) side penetrates and protrudes into the reaction chamber 2 (inside the support leg 13) and is fixed to the partition wall 16, and a reactive gas supply source (see FIG. The reaction gas is supplied from (not shown). Cooling water is supplied to the annular space 7b of the jacket pipe 7c through a cooling water pipe (not shown) so as to cool the reaction gas flowing in the nozzle pipe 7a.

  The nozzle tube 7a is a semiconductor in which the upper end (tip) is extended to the vicinity of the lower end (lower end of the heating region of the heater 6) in the direction of the central axis S1 of the heater 6 and the tip opening 7d is mounted on the susceptor 4. The reaction gas is opposed to the lower surface of the wafer 3, and the reaction gas supplied from the reaction gas supply source to the lower end of the nozzle tube 7 a is sprayed onto the surface of the semiconductor wafer 3 from the tip opening 7 d. ing. The position of the tip opening 7d of the nozzle tube 7a (the position where the reactive gas is blown against the surface of the semiconductor wafer 3) E is an intermediate position between the center C and the outer periphery of the semiconductor wafer 3 in the diameter direction (semiconductor wafer). Is set to be displaced from the center C.

A heat insulator 20 made of low-density carbon is disposed in the internal space 2 a of the reaction chamber 2 so as to surround the outer periphery of the support leg 13 and the outside of the susceptor 4. The heat insulator 20 is provided between the inner peripheral portion of the reaction chamber 2 and the outer peripheral portion of the support leg 13, and the lower end of the heat insulator 20 is outside the opening portion 11 a of the wall portion 11. A cylindrical (cylindrical) heat insulator body 20a fixed to the upper surface of the susceptor 4, and a top plate 20b that is disposed above the susceptor 4 with a space therebetween to close the upper end of the heat insulator body 20a, The heat for heating the semiconductor wafer 3 is prevented from being dissipated to the outside. The top plate 20b is provided with an exhaust port 20c whose center coincides with the central axis S1.
Note that the body portion 8 of the reaction chamber 2, the support leg 13, and the heat insulator body portion 20a of the heat insulator 20 are not limited to a cylindrical shape, and may be formed in a rectangular tube shape or other tubular shapes.

Next, the operation of the chemical vapor deposition apparatus 1 configured as described above will be described.
After mounting the semiconductor wafer 3 on the susceptor 4 in the load lock chamber, the support leg 13 is inserted into the reaction chamber 2 (in the heat insulator 20), and the partition wall 16 is joined to the wall portion 11 of the load lock chamber. The susceptor 4 is set at a predetermined position. Then, while the heater 6 is operated, the rotation mechanism 5 is operated and the susceptor 4 is rotated via the support leg 13, thereby rotating the semiconductor wafer 3 around the central axis S <b> 1 and the nozzle 7. A reactive gas (for example, carrier gas H ₂ and source gas SiH ₄ , C ₃ H ₈ ) is supplied to the nozzle tube 7a. The reactive gas supplied to the nozzle tube 7a is ejected from the tip opening 7d of the nozzle tube 7a, and at a position E displaced from the center C of the semiconductor wafer 3 by a distance e from its center C in the outer peripheral direction. Sprayed vertically from below to above.

By the spraying, the reactive gas is effectively urged and brought into contact with the surface 3a of the semiconductor wafer 3, and the CVD reaction is efficiently performed while flowing in the outer peripheral direction along the surface 3a to form a thin film f having a predetermined thickness. To do. The unreacted gas and the reaction product gas out of the reaction gas sprayed on the surface 3a of the semiconductor wafer 3 pass through the exhaust port 4b on the outer periphery of the susceptor 4, and the exhaust port 20c of the heat insulator 20 and the upper part of the reaction chamber 2 are passed through. It is discharged out of the reaction chamber 2 through the exhaust port 10 a of the flange 10. In this case, since the exhaust ports 20c and 10a are provided on the central axis S1 of the reaction chamber 2, the flow of the unreacted gas and the carrier gas can be smoothly discharged without being shifted to one side of the reaction chamber 2. The exhaust ports 20c and 10a are not limited to the positions described above, and may be provided at other positions.
The film thickness of the thin film f1 formed on the surface of the semiconductor wafer 3 is because the tip opening 7d of the nozzle tube 7a is displaced to the intermediate position in the radial direction of the semiconductor wafer 3 rotating around the center C. As shown in FIG. 3 (a), the region to which the reactive gas is sprayed is slightly thicker in a cross-sectional view, gradually becoming thinner on both sides, and thicker in a ring shape in a plan view. However, in practice, it may be considered that the film thickness is uniformly formed over the entire surface 3 a of the semiconductor wafer 3.

  As described above, the chemical vapor deposition apparatus 1 according to the first embodiment includes the cylindrical reaction chamber 2 into which the reaction gas can be introduced into the internal space 2a (inside the support leg 13), and the semiconductor wafer 3 on the bottom surface. A susceptor that can be mounted on the side by a support 12 and is fixed to a support leg 13 supported by a partition wall 16 of a load lock chamber via a bearing 15 and rotatably disposed in the internal space 2a of the reaction chamber 2. 4 and a rotation mechanism 5 for rotating the susceptor 4 about its axis by rotating the support leg 13 via a pinion 19 and an internal gear 17 by a driving means, and an outer peripheral portion of the reaction chamber 2. And a chemical gas provided with a heater 6 comprising a high-frequency induction coil for heating the semiconductor wafer 3 mounted on the susceptor 4 and a nozzle 7 for spraying a reaction gas onto the surface 3a of the semiconductor wafer 3. In the growth apparatus, the nozzle 7 is provided so that the tip end side of the nozzle tube 7 a protrudes into the reaction chamber 2 (support leg 13), and the tip opening 7 d faces the surface facing the lower side of the semiconductor wafer 3. In addition, the semiconductor wafer 3 is arranged at an intermediate position between the center C and the outer peripheral edge in the diameter direction of the semiconductor wafer 3.

Therefore, according to the chemical vapor deposition apparatus 1 according to the first embodiment, in the optimum region which is an intermediate position between the center C and the outer peripheral edge in the diameter direction of the semiconductor wafer 3, Since the reaction gas can be sprayed toward the surface 3a facing, the reaction gas is effectively urged and brought into contact with the surface 3a of the semiconductor wafer 3, and the thin film f1 having a predetermined thickness can be efficiently formed even with a small amount of reaction gas. 3 can be formed uniformly over the entire surface 3a, and the amount of reaction gas used can be reduced. In addition, the system for excluding the gas after reaction can be made compact.
In addition, since the surface 3a of the semiconductor wafer 3 is mounted on the lower surface of the susceptor 4 so that the temperature of the reaction gas is increased, an upward flow is generated and the contact with the surface 3a of the semiconductor wafer 3 is improved. Also from this point, the thin film f1 can be efficiently formed on the surface 3a, and the fine powder generated in the reaction chamber 2 can be prevented from adhering to the surface 3a, thereby improving the quality of the thin film f1. it can.

The heater 6 is arranged to heat the upper part of the reaction chamber 2, and the susceptor 4 is supported on an upper part of a support leg 13 rotated by the rotating mechanism 5 below the reaction chamber 2, Since the structure is arranged above the reaction chamber 2, the rotation mechanism 5 that rotates the susceptor 4 on which the semiconductor wafer 3 is mounted is heated by the heater 6 via the support legs 13. Even if the constituent members of the rotating mechanism 5 have sliding portions in the meshing portion of the pinion gear 17 and the internal gear 19 or the supporting portion of the rotating shaft 18 with respect to the partition wall 16, It is possible to prevent the sliding portion from being exposed to high heat and to wear out, thereby extending the life of the constituent members of the rotating mechanism 5 and improving the maintainability of the apparatus.
The susceptor 4 can be rotated around the central axis S1 of the reaction chamber 2 with the center C of the semiconductor wafer 3 aligned with the central axis S1 of the reaction chamber 2. By rotating around the central axis S1, the surface 3a of the semiconductor wafer 3 is uniformly heated by the heater 6 so that the temperature does not become uneven. In this respect as well, the surface 3a of the semiconductor wafer 3 is moved. The thin film f1 can be formed satisfactorily.

In the chemical vapor deposition apparatus 1 according to the above embodiment, the position E of the tip opening 7d of the nozzle tube 7a is set at an intermediate position between the center and the outer periphery of the semiconductor wafer 3, so that In addition, it is preferable that the uniformity of the film thickness formed on the entire surface 3a of the semiconductor wafer 3 can be obtained, but the position E of the tip opening 7d of the nozzle tube 7a need not be limited to the intermediate position. It may be set to an intermediate portion that is the periphery of the intermediate position, and may be set to a range from the center C in the diameter direction of the semiconductor wafer 3 to the intermediate portion. The intermediate portion includes not only a position of 1/2 of the radius R of the semiconductor wafer 3 but also a range of 1/4 to 3/4 of the radius R. When the position E of the tip opening 7d is displaced from the intermediate portion toward the outer peripheral edge of the semiconductor wafer 3, the reaction gas that does not function for film formation and flows out toward the outer peripheral edge increases. There is a possibility that a portion of the thick thin film is unevenly distributed on the edge side and the uniformity of the film thickness on the entire surface 3a of the semiconductor wafer 3 is lowered.
Further, as described above, the position of the tip of the nozzle tube 7a in the direction of the central axis S1 is set to the lower limit position of the heating area by the heater 6, but it is not necessary to limit to that position. Depending on the size of the diameter of the semiconductor wafer 3, the distance L from the surface 3a of the semiconductor wafer 3 is preferably set in the range of 1/2 to 5 times the diameter. When the distance L is smaller than the lower limit, the film thickness distribution is deteriorated. When the distance L is larger than the upper limit, the biasing pressure of the reactive gas contacting the surface 3a of the semiconductor wafer 3 is lowered, and a thin film having a predetermined thickness is obtained. Requires a large amount of reaction gas.

  Next, a chemical vapor deposition apparatus 1A according to a second embodiment of the present invention will be described with reference to FIG. In this chemical vapor deposition apparatus 1A, the susceptor 4 is fixed to a support leg 13 supported by the chemical vapor deposition apparatus 1 rotatably on a partition wall 16 of a load lock chamber, and the support leg 13 is rotated by a rotation mechanism 5. As a result, the susceptor 4 is rotated about the central axis S1 of the reaction chamber 2, whereas the support leg 13A is fixed to the partition wall 16, and the susceptor 4A can be rotated on the support leg 13A. The susceptor 4A is configured to rotate about the central axis S1 of the reaction chamber 2 by the flow of the reaction gas. Since other configurations are the same as those of the chemical vapor deposition apparatus 1, the same portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

The support leg 13A is provided with its axis line aligned with the central axis S1 of the reaction chamber 2 and with its lower end fixed to the upper surface of the partition wall 16, and a disk-like cap 21 at its upper end with an upper end flange 21a. Is fixed through. The susceptor 4A has a plurality of blades 22a formed on the outer peripheral portion of the disc-shaped susceptor main body 22 so as to be inclined with respect to the axis of the susceptor main body 22 and formed in the same manner as the turbine blades. The susceptor main body 22 is rotatably supported on the lower surface of the cap 21 via a bearing 23, and the lower surface on the outer peripheral side of the blade 22a is received by the upper step portion 13a of the support leg 13. Therefore, it is prevented from falling downward. Further, a plurality of exhaust ports 21 b penetrating vertically are provided at positions on the circumference concentric with the central axis S <b> 1 of the cap 21 facing the blades 22 a with a space in the circumferential direction.
The bearing 23 is similar to the bearing 15 in the chemical vapor deposition apparatus 1 in that a ball is placed in an annular groove having a V-shaped cross section formed to face the lower surface of the cap 21 and the upper surface of the susceptor 4A. It is inserted. In the case of the chemical vapor deposition apparatus 1A according to this embodiment, the nozzle 7 has an axis of the nozzle tube 7a aligned with the central axis S1 of the reaction chamber 2, and the position E of the tip opening 7d is the position of the semiconductor wafer 3. Located at the center C.

In the chemical vapor deposition apparatus 1A according to this embodiment, the reaction gas sprayed from the nozzle tube 7a of the nozzle 7 to the surface 3a of the semiconductor wafer 3 is evenly distributed from the center of the semiconductor wafer 3 toward the outer peripheral edge. The CVD reaction is performed while flowing to form a thin film f2 (see FIG. 3B) on the surface 3a, and after the unreacted gas and the carrier gas collide with the blade 22a from the outer peripheral edge, the exhaust port 21b of the cap 21 is opened. It passes through the top plate 20b of the heat insulator 20 and the exhaust ports 20c and 10a of the flange 10 of the reaction chamber 2 and is discharged to the outside. At this time, the susceptor 4A rotates around its axis (center C of the semiconductor wafer 3) due to the generation of rotational force caused by the collision of the unreacted gas and the carrier gas on the blade 22a. The thin film f2 is uniformly formed without unevenness.
The film thickness of the thin film f2 formed on the surface 3a of the semiconductor wafer 3 is the reaction gas as shown in FIG. 3B because the tip opening 7d of the nozzle tube 7a is located at the center C. The central region where the mist is sprayed is slightly thicker in a cross-sectional view and tends to be gradually thinner toward the outer peripheral side. However, in practice, in the uniformity of the film thickness over the entire surface 3a of the semiconductor wafer 3 There is no problem.

According to the chemical vapor deposition apparatus 1A according to this embodiment, the tip opening portion 7d of the nozzle 7 is opposed to the surface 3a of the semiconductor wafer 3 as in the chemical vapor deposition apparatus 1 according to the embodiment. Since the reaction gas is sprayed from the tip opening 7d toward the surface 3a, the reaction gas is effectively urged and brought into contact with the surface 3a of the semiconductor wafer 3, and even a small amount of reaction gas can be efficiently determined. The thin thin film f2 can be formed uniformly over the entire surface 3a of the semiconductor wafer 3, and the amount of reaction gas used can be reduced.
Further, since the susceptor 4A is rotated by the action of the blades 22a provided on the outer peripheral portion thereof, since the susceptor 4A is not provided with a rotation mechanism having a sliding portion or the like in order to rotate the susceptor 4A, the configuration of the rotation mechanism There is no worry that the member will be worn out by high heat, and maintenance is very good.

  In the chemical vapor deposition apparatus 1A, since the position of the tip opening 7d of the nozzle tube 7a is positioned at the center C of the semiconductor wafer 3, the reaction gas is evenly directed toward the outer peripheral edge of the semiconductor wafer 3. Therefore, it is preferable that an equal rotational force is generated on the blades 22a on the entire circumference of the susceptor 4A, and the susceptor 4A is smoothly rotated. However, the position of the tip opening 7d does not need to be exactly coincident with the center C, and is near the center, that is, from the center C to a position displaced by ½ of the radius in the radial direction of the semiconductor wafer 3. A range may be set. If the position of the tip opening 7d is displaced from the range in the direction of the outer peripheral edge of the semiconductor wafer 3, the rotational force acting on each blade 22a may become uneven and the susceptor 4A may not be smoothly rotated. .

1 is a longitudinal sectional view showing a chemical vapor deposition apparatus according to a first embodiment of the present invention. It is a longitudinal cross-sectional view which shows the chemical vapor deposition apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the formation state of the thin film to a semiconductor wafer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Chemical vapor deposition apparatus 2 Reaction chamber 3 Semiconductor wafer 3a Surface 4, 4A Susceptor 4b, 10a, 20c, 21b Exhaust port 5 Rotating mechanism 6 Heater 7 Nozzle 7a Nozzle tube 8 Body 10 Flange 11 Load lock chamber wall Part 12 Supporting tool 13, 13A Supporting leg 15, 23 Bearing 16 Bulkhead 17 of load lock chamber 17 Internal gear 18 Rotating shaft 19 Pinion gear 20 Thermal insulator 21 Cap 22a Blade C Center E Position of nozzle tip opening S1 Center shaft f1, f2 thin film

Claims (4)

A reaction chamber into which a reaction gas can be introduced; a susceptor in which a semiconductor wafer can be mounted on the lower surface side; and a rotation mechanism that rotates the susceptor around its axis; and the susceptor In a chemical vapor deposition apparatus comprising a heater for heating a semiconductor wafer mounted on a nozzle and a nozzle for spraying a reaction gas on the surface of the semiconductor wafer,
The nozzle is provided such that the tip end side protrudes into the reaction chamber, the tip opening is opposed to the surface facing the lower side of the semiconductor wafer, and an intermediate between the center and the outer peripheral edge from the center in the diameter direction of the semiconductor wafer. A chemical vapor deposition apparatus characterized in that the chemical vapor deposition apparatus is disposed within a range up to a portion.   The heater is arranged to heat the upper part of the reaction chamber, and the susceptor is supported on an upper part of a support leg rotated by the rotating mechanism below the reaction chamber, and arranged on the upper part of the reaction chamber. The chemical vapor deposition apparatus according to claim 1, wherein:   3. The chemical vapor deposition apparatus according to claim 1, wherein the nozzle has the tip opening disposed at an intermediate portion between a center and an outer peripheral edge in a diameter direction of the semiconductor wafer. 4. The susceptor is rotatable about the central axis of the reaction chamber in a state where the center of the semiconductor wafer is aligned with the central axis of the reaction chamber. 5. Chemical vapor deposition equipment.

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