JP4933409B2 - Semiconductor manufacturing apparatus and semiconductor manufacturing method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus and a semiconductor manufacturing method for forming a film by supplying a process gas while heating the upper surface of a semiconductor wafer.

  In recent years, along with demands for lower prices and higher performance of semiconductor devices, high quality such as film thickness uniformity is required in addition to high productivity in the film forming process.

  As a method for improving productivity while maintaining high quality, a single-wafer type semiconductor manufacturing apparatus that performs epitaxial growth by heating a wafer placed on a table while rotating at high speed is known (for example, Patent Documents). 1 etc.).

In the above technique, in order to prevent the wafer from being lifted or displaced during rotation, the outer peripheral edge of the table on which the wafer is placed swings with the rotation of the rotation mechanism, and the wafer is moved from the upper surface side. A member for pressing in the table direction is provided. However, because of the structure that suppresses the lift and misalignment of the wafer during rotation at two points, for example, when performing high-speed rotation as high as 1500 rpm, the support becomes insufficient, and an error is likely to occur in the rotation trajectory. That is, there is a problem that the film thickness on the upper surface of the wafer becomes non-uniform.
JP 11-97515 A

  As described above, along with demands for lower cost and higher performance of semiconductor devices, higher productivity such as film thickness uniformity is required in addition to high productivity in the film forming process.

  SUMMARY OF THE INVENTION In view of the problems of the prior art, an object of the present invention is to provide a semiconductor manufacturing method and a semiconductor manufacturing apparatus capable of reliably supporting a wafer during high-speed rotation and performing uniform film formation on the upper surface of the wafer. It is what.

The semiconductor manufacturing apparatus according to the present invention includes a reaction chamber into which a wafer is carried in, a gas supply mechanism that supplies a first process gas containing a source gas to the reaction chamber, and a first process that is supplied from the gas supply mechanism. A rectifying plate that supplies gas to the upper surface side of the wafer in a rectified state, a gas discharge mechanism that discharges the first process gas from the reaction chamber, and a first support member that supports the wafer from the lower surface side at a predetermined position in the reaction chamber And a second support member that is provided above the first support member and supports the outer peripheral edge of the wafer over the entire circumference from the upper surface side, and the second support member is moved up and down to support the wafer. And an elevating drive mechanism for performing opening, a rotary drive mechanism for rotating the wafer together with the first and second support members, and a heating mechanism for heating the wafer supported by the first and second support members from the lower surface side. A mechanism, the support portions of the wafer in the second support member, and wherein the bevel in der Rukoto formed in the outer peripheral edge of the wafer.

  In the semiconductor manufacturing apparatus of the present invention, it is preferable that the gas supply mechanism supplies a second process gas containing hydrogen gas or inert gas to the outer peripheral portion of the wafer.

In the semiconductor manufacturing method of the present invention, a wafer is carried into a reaction chamber, the wafer is placed on a first support member, and the outer peripheral edge of the placed wafer is moved from the upper surface side of the wafer by the second support member. The first process gas including the source gas is supplied in a rectified state to the upper surface side of the supported wafer, and the second process gas including hydrogen gas or inert gas is supplied to the outer periphery of the wafer. The wafer is heated while being rotated together with the first and second support members, and a film is formed on the upper surface side of the wafer.

  According to the present invention, the wafer can be reliably supported during high-speed rotation, and uniform film formation can be performed on the upper surface of the wafer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional view of the semiconductor manufacturing apparatus of this embodiment. As shown in the figure, in the reaction chamber 11 where the wafer w is formed, a gas supply port 12a for supplying a process gas or the like to the upper surface of the wafer w from above the reaction chamber 11, and the outer peripheral portion of the wafer w For example, hydrogen gas, an inert gas such as Ar or He, a gas supply port 12b for supplying a cleaning gas containing HCl, and the like, a gas is discharged from below the reaction chamber 11, and the pressure in the reaction chamber 11 is discharged. Is provided with a gas discharge port 13 for controlling the pressure at a constant (normal pressure).

  In the upper part of the reaction chamber 11, a rectifying plate 14a for supplying a process gas supplied from the gas supply port 12a to the upper surface of the wafer w in a rectified state, and a hydrogen gas or an inert gas supplied from the gas supply port 12b. A rectifying plate 14b is provided for supplying a gas containing gas to the outer peripheral portion (outside) of the wafer w in a rectified state. And the partition plate 15 is installed in the lower part of these rectifying plates 14a and 14b between the rectifying plates 14a and 14b so that a lower end may be 20 mm high from the surface of the wafer w.

  At the bottom of the reaction chamber 11, a rotation drive mechanism 16 for rotating a wafer w composed of a motor (not shown), a rotation shaft (not shown), and the like, and the wafer w are placed on the rotation drive mechanism 16. A lower support member 17 is installed for this purpose. Here, the lower support member 17 is a susceptor, but a holder having an opening may be used. Above the lower support member 17, for example, a ring-shaped upper support member 18 is provided, and is lifted and lowered in the vertical direction by the lift drive mechanism 19 to support and release the wafer w. The upper support member 18 supports the outer peripheral edge of the wafer w from the upper surface side of the wafer w over the entire circumference.

  FIG. 2 shows an enlarged view of a main part for explaining the wafer support structure. As shown in the figure, the wafer w placed on the lower support member 17 is composed of a film-forming surface A and a bevel portion B formed on the outer peripheral edge of the wafer w, for example, about 400 μm. The inner wall surface C of the support member 18 is located on the bevel portion B of the wafer w. Further, it is preferable that a slight gap (for example, 0.2 μm) is provided between the upper support member 18 and the lower support member 17 and the bevel portion B of the wafer w so as to cope with the thermal expansion of the wafer w.

  The inner wall surface C of the upper support member 18 is formed to be parallel to the bevel portion B of the wafer w. However, the same taper is provided for temperature distribution control and effective support. preferable. Further, the cross-sectional shape of the inner wall surface C of the upper support member 18 is not particularly limited. For example, it may be provided with a stepped portion or may be a curved surface as long as it can prevent the wafer w from being lifted upward during rotation.

  FIG. 3 is a perspective view for explaining the wafer support structure. As shown in the figure, the bevel portion B of the wafer w is surrounded by the upper support member 18 formed in a ring shape over the entire circumference from the upper surface side of the wafer w.

  An in-heater 20a for heating the wafer w is installed below the lower support member 17, and an out-heater 20b for heating the peripheral portion of the wafer w is installed between the lower support member 17 and the in-heater 20a. Has been. A disc-shaped reflector 21 for efficiently heating the wafer w is installed below the in-heater 20a.

  For example, an Si epitaxial film is formed on the upper surface of the wafer w using such a semiconductor manufacturing apparatus.

  First, for example, a φ200 mm wafer w is introduced into the reaction chamber 11 by a transfer arm (not shown) and placed on the lower support member 17.

  Next, the ring-shaped upper support member 18 is lowered by the elevating drive mechanism 19 to support from the upper surface side of the wafer w so as to surround the bevel portion of the outer peripheral edge of the wafer w over the entire circumference.

  Next, the temperature of the in-heater 20a and the out-heater 20b is controlled so that the temperature of the wafer w becomes, for example, 1100 ° C., and the wafer w is rotated at a high speed of, for example, 1500 to 2000 rpm by the rotation drive mechanism 16. At this time, the rotation trajectory of the wafer w is maintained substantially constant by the cooperation of the upper support member 18 and the lower support member 17.

Next, a process gas prepared to have a trichlorosilane (TCS) concentration of, for example, 2.5% is introduced from the gas supply port 12a by, for example, 50 SLM, and the wafer w is rectified through the rectifying plate 14a. Then, an Si epitaxial film is grown on the upper surface of the wafer w. At this time, H ₂ gas, for example, is introduced from the gas supply port 12b at, for example, 50 SLM and supplied to the outer peripheral portion of the wafer w in a rectified state via the rectifying plate 14b, thereby diluting the process gas on the outer peripheral portion of the wafer w. . The supplied dilution gas can be prevented from flowing into the upper surface of the wafer w and being mixed with the process gas by controlling the partition plate 15, the supply speed, and the concentration. Excess process gas, dilution gas, reaction byproducts, and the like are discharged from the gas discharge port 13 so that the pressure in the reaction chamber 11 is controlled to normal pressure.

  Then, an Si epitaxial film is grown on the upper surface of the wafer w until a desired film thickness (for example, 150 μm) is obtained. After completion of the film forming process, as shown in FIG. 4, when the upper support member 18 is raised by the elevating drive mechanism 19, the wafer w is moved up by the push pin (not shown) above the lower support member 17, The wafer w is held by a transfer arm (not shown) and unloaded from the reaction chamber 11.

  Thus, by providing the upper support member 18, the outer peripheral edge of the wafer w can be reliably supported by the cooperation with the lower support member 17 during high-speed rotation. Therefore, since the wafer w is prevented from being lifted or displaced, the uniformity of the film thickness of the epitaxial film or the like formed on the upper surface of the wafer w can be achieved.

  Furthermore, when supporting at a point, a singular point in the temperature distribution occurs due to the difference in thermal conductivity between the wafer w and the support member, but the outer peripheral edge of the wafer w can be supported at a uniform temperature. It becomes. And it becomes possible to suppress the occurrence of slipping of the wafer w due to the singular point.

  Further, by providing the upper support member 18, a structure in which the process gas (source gas) does not easily flow into the gap between the wafer w and the lower support member 17 can be obtained. Further, since the structure does not return even if it flows in, it is possible to suppress the generation of deposits due to the flowing process gas (source gas) in the gap portion. Accordingly, it is possible to suppress a decrease in production efficiency due to the adhesion between the wafer w and the lower support member 17.

  Further, in the present embodiment, by providing the rectifying plate 14a and rectifying the gas, the process gas can be uniformly supplied to the upper surface of the wafer w, and the film thickness can be made uniform.

  Further, in the present embodiment, the source gas staying around the wafer w is provided by supplying a rectifying plate 14b and supplying hydrogen gas rectified outside the wafer w or an inert gas such as Ar or He. It can be effectively removed. Further, even when the source gas remains, the equilibrium can be shifted in the direction in which the film formation reaction is suppressed, and the generation of deposits on the outer peripheral portion of the wafer w can be suppressed. Further, even when deposits are generated, the deposits can be removed by supplying a cleaning gas containing HCl.

  In the present embodiment, the partition plate 15 is installed between the rectifying plate 14a and the rectifying plate 14b so that the lower end is, for example, 20 mm high from the surface of the wafer w. The mixed state of the process gas supplied to the upper surface of the wafer w and the gas supplied to the outer periphery of the wafer w is mainly governed by the speed and concentration of the gas supplied to the outer periphery of the wafer w. The partition plate 15 can more effectively suppress gas mixing.

  Further, from the viewpoint of suppressing gas mixing, it is considered that the partition plate 15 is preferably provided up to the vicinity of the wafer w. However, the gas supplied to the upper surface of the rotating wafer w forms a boundary layer on the upper surface of the wafer w, and the surplus gas is discharged in the outer peripheral direction. There is. For example, the amount of deposit on the partition plate 15 when the installation height of the partition plate 15 is changed under desired process conditions may be measured and arranged so that the amount of deposit generated is reduced. .

  Further, according to the present embodiment, it is possible to form a film such as an epitaxial film on the upper surface of the semiconductor wafer w with high productivity. As well as improving the yield of the wafer, it is possible to improve the yield of the semiconductor device formed through the element formation process and the element isolation process and to stabilize the element characteristics. In particular, an excellent element can be obtained by being applied to an epitaxial formation process of a power semiconductor device such as a power MOSFET or IGBT that requires a thick film growth of 100 μm or more in an N-type base region, a P-type base region, an insulating isolation region, or the like. It becomes possible to obtain characteristics.

In the present embodiment, the case of forming the Si single crystal layer (epitaxial film) has been described. However, the present embodiment can also be applied when forming the poly-Si layer. The present invention can also be applied to film formation other than Si film such as SiO ₂ film and Si ₃ N ₄ film, and compound semiconductor such as GaAs layer, GaAlAs and InGaAs. Various other modifications can be made without departing from the scope of the invention.

FIG. 6 is a cross-sectional view of a semiconductor manufacturing apparatus according to one embodiment of the present invention. The principal part enlarged view explaining the support structure of the wafer in 1 aspect of this invention. FIG. 6 is a perspective view illustrating a wafer support structure in one embodiment of the present invention. FIG. 6 is a cross-sectional view of a semiconductor manufacturing apparatus according to one embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Reaction chamber, 12a, 12b ... Gas supply port, 13 ... Gas discharge port, 14a, 14b ... Rectifying plate, 15 ... Partition plate, 16 ... Rotary drive mechanism, 17 ... Lower support member, 18 ... Upper support member, 19 ... Elevating drive mechanism, 20a ... in heater, 20b ... out heater, 21 ... reflector.

Claims (3)

A reaction chamber into which wafers are loaded;
A gas supply mechanism for supplying a first process gas including a source gas to the reaction chamber;
A rectifying plate for supplying the first process gas supplied from the gas supply mechanism to the upper surface side of the wafer in a rectified state;
A gas discharge mechanism for discharging the first process gas from the reaction chamber;
A first support member for supporting the wafer from a lower surface side at a predetermined position in the reaction chamber;
A second support member provided above the first support member and supporting the outer peripheral edge of the wafer over the entire circumference from the upper surface side;
An elevating drive mechanism for elevating and lowering the second support member to support and release the wafer;
A rotation drive mechanism for rotating the wafer together with the first and second support members;
A heating mechanism for heating the wafer supported by the first and second support members;
With
The support portion of the wafer in the second support member, the semi-conductor manufacturing apparatus you wherein within bevel formed on the outer peripheral edge of the wafer. The gas supply mechanism, according to claim 1 Symbol mounting a semiconductor manufacturing apparatus of the second process gas and supplying the outer peripheral portion of the wafer containing hydrogen gas or an inert gas. Bring wafers into the reaction chamber,
Placing the wafer on a first support member;
The outer peripheral edge of the wafer placed above is supported over the entire circumference from the upper surface side of the wafer by a second support member,
Supplying a first process gas containing a source gas in a rectified state to the upper surface side of the supported wafer;
Supplying a second process gas containing hydrogen gas or inert gas to the outer periphery of the wafer;
Heating the wafer while rotating with the first and second support members;
Semiconductors manufacturing how to characterized by forming a film on an upper surface side of the wafer.

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