JP2009135202A - Semiconductor manufacturing device and semiconductor manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing method and a manufacturing device, which securely holds a wafer at a high temperature and a high speed rotation, and forms a uniform film on the wafer. <P>SOLUTION: The semiconductor manufacturing device is provided with: a reaction chamber 11 to which the wafer (w) is introduced and in which the film is formed; a gas supply mechanism 12 for supplying process gas comprising source gas to the reaction chamber 11, a gas exhaust mechanism 13 exhausting gas from the reaction chamber 11; a rotation driving mechanism 16 rotating the wafer (w); heaters 19a and 19b for heating the wafer (w); a susceptor 15 for holding the wafer in the reaction chamber 11; a fixing member 17 disposed at an outer periphery of the susceptor 15; and a wafer come-out preventing component 18 in which one end 18a is fixed to the fixing member 17, the other end 18b is arranged to become substantially in the same position as a counter sinking wall face 15a of the susceptor 15 at a normal temperature, and which consists of a material having a positive thermal expansion coefficient. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 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. Up to now, semiconductor manufacturing apparatuses that perform epitaxial growth by rotating while heating have been used, but it is expected that uniform film formation with high productivity will be obtained by further increasing the rotation.

  Usually, in such a semiconductor manufacturing apparatus, a wafer is held and heated and rotated by a susceptor. Here, since thermal stress is applied to the wafer during heating, a method of releasing the thermal stress by providing a gap to some extent on the back surface of the wafer is used. However, when the wafer is held and rotated at a high speed in this way, there arises a problem that if the pressure on the front and back surfaces of the wafer is uneven due to some problem during the film formation, the wafer is lifted.

In order to suppress the lift of the wafer, for example, it is considered effective to provide a member that presses the wafer (see, for example, Patent Document 1). However, the mechanism of the pressing member is complicated, and there is a problem that reaction by-products accumulate on the pressing member, dust is generated due to sliding during operation, and the reaction chamber is contaminated. Therefore, there is a demand for a mechanism that suppresses the lift of the wafer with a mechanism that is as simple as possible.
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 An object of the present invention is to provide a semiconductor manufacturing method and a semiconductor manufacturing apparatus that can reliably hold a wafer during high-temperature and high-speed rotation and can perform uniform film formation on the wafer. is there.

  A semiconductor manufacturing apparatus of the present invention includes a reaction chamber into which a wafer is introduced, a gas supply mechanism for supplying a process gas including a source gas to the reaction chamber, and a gas discharge mechanism for discharging gas from the reaction chamber. A heater for heating the wafer, a susceptor for holding the wafer in the reaction chamber, a rotation drive mechanism connected to the susceptor and rotating the wafer, and connected to the rotation drive mechanism, and the outer periphery of the susceptor A fixing member installed on the susceptor, and one end is fixed to the fixing member, and the other end is installed at a room temperature so as to be substantially at the same position as the counterbore wall of the susceptor, and has a positive thermal expansion coefficient. It is characterized by comprising a wafer detachment prevention component made of a material having the same.

  In the semiconductor manufacturing apparatus of the present invention, the other end moves to the center side of the susceptor by heating.

  In the semiconductor manufacturing apparatus of the present invention, the material constituting the wafer detachment prevention part is preferably SiC or carbon coated with SiC.

  In the semiconductor manufacturing apparatus of the present invention, the material constituting the fixing member is preferably quartz.

  In the semiconductor manufacturing method of the present invention, a wafer is carried into a reaction chamber, the wafer is placed on a susceptor, one end is fixed, and a wafer detachment prevention component made of a material having a positive thermal expansion coefficient is provided. Install the other end so that it is substantially the same position as the counterbore wall of the susceptor, supply process gas including source gas to the surface of the wafer in a rectified state, heat the wafer while rotating it, The other end is arranged so as to be inside the counterbore wall surface of the susceptor by thermal expansion, and the film is formed on the surface of the wafer.

  According to the present invention, the wafer can be reliably held during high-speed rotation, and uniform film formation can be performed on 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, a gas supply port 12 for supplying a process gas including a source gas to the upper surface of the wafer w from above the reaction chamber 11 and a gas supply to the reaction chamber 11 in which the wafer w is formed into a film. A rectifying plate 14 is provided for supplying the process gas supplied from the port 12 to the upper surface of the wafer w in a rectified state. A gas discharge port 13 for discharging gas and controlling the pressure in the reaction chamber 11 to be constant (normal pressure) is installed below the reaction chamber 11.

  A susceptor 15 made of, for example, SiC for placing the wafer w is placed below the current plate 14. The susceptor 15 is connected to a rotation drive mechanism 16 including a motor (not shown), a rotation shaft (not shown), and the like. At the outer periphery of the susceptor 15, a ring-shaped fixing member 17 made of, for example, quartz is connected to the rotation drive mechanism 16. Further, as shown in a top view in FIG. 2, an end 18 a of a plate-shaped wafer detachment prevention component 18 having a length of, for example, 50 mm is fixed to the fixing member 17. The wafer detachment prevention component 18 is made of, for example, carbon coated with SiC, and is installed on the fixing member 17 at three or more locations. As shown in the enlarged view of FIG. 3, the other end 18b of the wafer detachment prevention component 18 is installed so as to be substantially at the same position as the counterbore wall 15a of the susceptor 15 at room temperature. A play of several μm is provided between the end of the wafer w to be placed and the counterbore wall 15 a of the susceptor 15.

  In the susceptor 15, an inheater 19 a for heating the wafer w is installed below the susceptor 15, and an outheater 19 b for heating the peripheral portion of the wafer w is installed between the susceptor 15 and the inheater 19 a. Has been. A disc-shaped reflector 20 for efficiently heating the wafer w is installed below the in-heater 19a.

  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 susceptor 15 using lift pins (not shown).

  Next, the temperature of the in-heater 19a and the out-heater 19b is controlled so that the temperature of the wafer w becomes 1100 ° C., and the wafer w is rotated at a high speed of, for example, 900 rpm or more by the rotation drive mechanism 16. At this time, as shown in FIG. 4, the wafer detachment prevention component 18 extends by about 200 μm due to thermal expansion, and the end 18 b is located on the inner side (on the bevel portion) from the wafer w end.

Then, a process gas diluted with H ₂ is introduced at, for example, 50 to 100 SLM from the gas supply port 12 so that, for example, the trichlorosilane (TCS) concentration becomes 2 to 4%, for example, and rectified via the rectifying plate 14. In the state, it is supplied to the upper surface of the wafer w. Excess process gas, Cl ₂ gas generated by the film formation reaction, 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.

  In this manner, the wafer w is heated, and the process gas is supplied while rotating at a high speed in a state where the end portion 18b of the wafer detachment prevention component 18 is positioned on the bevel portion of the wafer w. Then, an Si epitaxial film is grown on the upper surface of the wafer w until a desired film thickness is obtained, for example, 150 μm.

  After the film forming process is completed, the wafer detachment prevention component 18 is cooled together with the wafer w, and the end 18b of the wafer detachment prevention component 18 located on the bevel portion of the wafer w is outside the end of the wafer w. Shrink until Thereafter, the wafer w is lifted by lift pins (not shown) and unloaded from the reaction chamber 11 by a transfer arm (not shown).

  Thus, by providing the wafer detachment prevention component 18 using the difference in thermal expansion coefficient, it becomes possible to stably support the susceptor 15 even at high speed rotation. Further, it is possible to suppress the floating due to the uneven vertical pressure of the wafer w. For example, when some trouble occurs during the film formation reaction and the gas supply is stopped, or when the rotation of the susceptor 15 is stopped, the upper portion of the wafer w is in a reduced pressure state. Even in such a case, the end portion 18b of the wafer detachment prevention component 18 can press the bevel portion of the wafer w and suppress the wafer w from being lifted.

  Further, when the wafer w is lifted, dropped from the susceptor 15 and damaged, it is necessary to perform maintenance by opening the reaction chamber 11, but the maintenance frequency can be greatly reduced.

In the present embodiment, a ring-shaped fixing member 17 made of quartz is provided on the outer periphery of the susceptor 15 and the end of the wafer detachment prevention component is fixed. Quartz is also suitable because quartz has a small coefficient of thermal expansion of 5.6 × 10 ⁻⁷ mm / ° C., but is not necessarily quartz, and radial expansion due to thermal expansion can be suppressed. It only has to be possible. For example, even if the thermal expansion coefficient is smaller than that of the material constituting the susceptor (for example, SiC), or the same material (for example, SiC), it may be arranged so that the temperature rise can be suppressed.

  Further, although SiC coated carbon is used for the wafer detachment prevention component, it is not limited to carbon, and for example, a material stable at a high temperature of 1100 ° C. or higher can be used. However, in order to hold down the bevel portion of the wafer w due to thermal expansion, it is necessary to extend the gap between the wafer w and the counterbore wall surface of the susceptor to be less than the gap + the bevel width of the wafer w. Therefore, it is necessary that the material has a positive thermal expansion coefficient within a predetermined range depending on the design dimension of the susceptor or the like.

For example, when carbon having a thermal expansion coefficient of 4.5 × 10 ⁻⁶ mm / ° C. is used in a 50 mm long wafer detachment prevention component, the elongation is 225 μm and the thermal expansion coefficient is 3.9 × 10 ⁻⁶ mm / When SiC at 0 ° C. is used, the elongation is 195 μm. The length required in this way is not less than the gap (for example, several μm) between the wafer w and the counterbore wall surface of the susceptor and is not more than the gap + bevel width of the wafer w (for example, about 400 μm). What is necessary is just to design the dimension and arrangement of the wafer detachment prevention parts.

  If a material having a sufficiently large difference in thermal expansion coefficient between the susceptor and the wafer detachment prevention component is selected, it is possible to fix the wafer detachment prevention component to the susceptor body without providing a fixing member on the outer periphery of the susceptor. .

  In addition, according to the present embodiment, a film such as an epitaxial film can be formed on 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. Further, 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 top view which shows arrangement | positioning of the fixing member in one aspect | mode of this invention, and wafer removal prevention components. The edge part enlarged view of the wafer removal prevention component in 1 aspect of this invention. The figure which shows expansion | extension by the thermal expansion of the wafer removal prevention component in 1 aspect of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Reaction chamber, 12 ... Gas supply port, 13 ... Gas discharge port, 14 ... Rectifying plate, 15 ... Susceptor, 15a ... Counterbore wall surface, 16 ... Rotation drive mechanism, 17 ... Fixing member, 18 ... Wafer removal prevention component, 18a , 18b ... end, 19a ... in-heater, 19b ... out-heater, 20 ... reflector.

Claims (5)

A reaction chamber into which the wafer is introduced;
A gas supply mechanism for supplying a process gas including a source gas to the reaction chamber;
A gas discharge mechanism for discharging gas from the reaction chamber;
A heater for heating the wafer;
A susceptor for holding the wafer in the reaction chamber;
A rotational drive mechanism connected to the susceptor for rotating the wafer;
A fixing member connected to the rotation driving mechanism and installed on the outer periphery of the susceptor;
Wafer detachment prevention made of a material having a positive thermal expansion coefficient, with one end fixed to the fixing member and the other end positioned substantially at the same position as the counterbore wall of the susceptor at room temperature A semiconductor manufacturing apparatus comprising a component.   The semiconductor manufacturing apparatus according to claim 1, wherein the other end moves to the center side of the susceptor by heating.   3. The semiconductor manufacturing apparatus according to claim 1, wherein the material constituting the wafer detachment prevention component is SiC or carbon coated with SiC.   4. The semiconductor manufacturing apparatus according to claim 1, wherein the material constituting the fixing member is quartz. Bring wafers into the reaction chamber,
The wafer is placed on the susceptor and one end is fixed, and the other end of the wafer detachment prevention part made of a material having a positive thermal expansion coefficient is substantially connected to the counterbore wall of the susceptor. Install it at the same position,
Supplying a process gas including a source gas to the surface of the wafer in a rectified state;
Heating while rotating the wafer, and arranging the other end to be inside the counterbore wall surface of the susceptor by thermal expansion, and forming a film on the surface of the wafer Method.

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