JP2014116356A - Semiconductor manufacturing method and semiconductor manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly adjust in-plane temperature distribution of a wafer correspondingly to a change in the in-plane temperature distribution of the wafer without increasing the number of zones.SOLUTION: An inner susceptor for exchange is previously housed in an inner susceptor housing part connected with a reaction chamber, and a wafer is introduced into the reaction chamber and placed on the inner susceptor which is carried in beforehand. The inner susceptor and the wafer are placed on an outer susceptor with an opening which is closed by mounting the inner susceptor, provided in the center, and heated from a lower side. Process gas is supplied from an upper side onto the wafer while being rectified, the wafer is rotated, and deposition is performed on the wafer. On the basis of definition information defining an exchange parameter of the inner susceptor and the inner susceptor for exchange beforehand, the inner susceptor for exchange is selected, the deposition on the wafer is temporarily stopped, the inner susceptor is exchanged with the selected inner susceptor for exchange, and then the deposition onto the wafer is resumed.

Description

  The present invention relates to a semiconductor manufacturing method and a semiconductor manufacturing apparatus for forming an epitaxial film on a wafer surface placed on a susceptor.

  In general, in a semiconductor manufacturing process, a CVD (Chemical Vapor Deposition) apparatus is used to form a thin film such as an epitaxial film on a wafer surface. In this CVD apparatus, a wafer is placed on a susceptor made of, for example, SiC, and a process gas is supplied from above in a rectified state while being heated and rotated, whereby a thin film is formed on the wafer surface.

  Further, in recent years, with the increase in speed and withstand voltage in power semiconductor devices such as power MOSFETs and IGBTs (insulated gate bipolar transistors), an epitaxial film formed on a wafer has a thick film growth of about several tens to 100 μm. Is required. Furthermore, as the diameter of the wafer increases, in order to perform film formation on the wafer surface with higher accuracy, further in-plane temperature distribution of the wafer is required.

  In response to these requirements, in conventional CVD apparatuses, for example, an in-heater that mainly controls the temperature at the center of the wafer and an out-heater that controls the temperature at the outer periphery of the wafer are arranged on the back side of the wafer, respectively. While being heated and rotated, the temperature distribution in the radial direction is measured, and the outputs of the in-heater and out-heater are adjusted based on the measurement results. Further, in order to further uniform the in-plane temperature distribution of the wafer, the heating between the central portion and the outer peripheral portion of the wafer is adjusted more finely by increasing the number of zones of the heater.

JP 2001-267254 A JP 2000-203991 A Special table 2009-530806 JP 2010-028098 A

  However, when the number of heater zones is increased as in the prior art described above, it becomes necessary to individually connect power supply components to each heater, resulting in a complicated heater unit structure and an increased number of components.

  It is also possible to predict the temperature distribution according to the type of wafer and perform film formation using a susceptor according to the temperature distribution. However, when the in-plane temperature distribution fluctuates during the film formation process, only temperature control by the heater is performed. However, there is a problem that it is difficult to control the in-plane temperature distribution sufficiently.

  Accordingly, in view of the above-described problems of the prior art, the present invention provides a semiconductor manufacturing method capable of uniformly adjusting the in-plane temperature distribution of a wafer in response to a change in the in-plane temperature distribution of the wafer without increasing the number of zones. It is another object of the present invention to provide a semiconductor manufacturing apparatus.

  In a semiconductor manufacturing method according to an embodiment of the present invention, a replacement inner susceptor is stored in advance in an inner susceptor storage unit connected to a reaction chamber, the wafer is introduced into the reaction chamber, and the introduced wafer is The inner susceptor and the wafer are placed on an outer susceptor that is placed on an inner susceptor that is loaded in advance, and an opening that is shielded by mounting of the inner susceptor is provided in the center. The wafer is heated from below via a susceptor, process gas is supplied from above to the wafer in a rectified state, and the wafer is rotated to form a film on the wafer, and the exchange parameters of the inner susceptor And the replacement inner susceptor based on predefined definition information. Selecting the replacement inner susceptor, temporarily stopping the film formation on the wafer, replacing the inner susceptor with the selected replacement inner susceptor, and restarting the film formation on the wafer. Features.

  The semiconductor manufacturing apparatus according to an embodiment of the present invention includes a reaction chamber into which a wafer is introduced, a gas supply mechanism that supplies a process gas to the reaction chamber, an inner susceptor having a smaller diameter than the wafer, and the inner An outer susceptor having an opening shielded by mounting of the susceptor is provided at a central portion, and a susceptor on which the wafer is placed, a rotating portion that supports the outer peripheral portion of the outer susceptor and rotates the wafer, A heater provided in the rotating part for heating the wafer from below through the susceptor, a push-up pin provided in the rotating part for raising / lowering the inner susceptor, and provided on an upper part of the reaction chamber, A temperature measuring device for measuring an in-plane temperature of the wafer, and the inner chamber connected to the reaction chamber. An inner susceptor storage section for storing a replacement inner susceptor to be replaced, a transport section for loading and unloading the inner susceptor and the replacement inner susceptor between the inner susceptor storage section and the reaction chamber; A storage device that preliminarily stores definition information defining the correspondence between the replacement parameter of the inner susceptor and the replacement inner susceptor, and the in-plane temperature distribution is calculated from the in-plane temperature, and the in-plane temperature distribution and the definition A control unit that selects the replacement inner susceptor based on the information and instructs the replacement with the inner susceptor.

1 is a schematic diagram illustrating an example of the overall configuration of a semiconductor manufacturing apparatus according to Embodiment 1. FIG. Sectional drawing which shows the example of whole structure of the reaction chamber shown in FIG. The principal part enlarged view of the susceptor shown in FIG. The top view which shows the specific example of the wafer conveyance hand and inner susceptor conveyance hand of the conveyance robot shown in FIG. The figure which shows the specific example of the inner susceptor installed in the reaction chamber shown in FIG. 1, and the replacement | exchange inner susceptor stored in the inner susceptor storage part. The figure which shows the relationship between the in-plane temperature of the wafer shown in FIG. 2, and the distance from a center. 5 is a flowchart showing a specific example of the semiconductor manufacturing method according to the first embodiment. Sectional drawing explaining operation | movement at the time of carrying in / out of a wafer. Sectional drawing explaining operation | movement at the time of carrying in / out of an inner susceptor. 9 is a flowchart showing a specific example of a semiconductor manufacturing method according to the second embodiment.

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

<Embodiment 1>
FIG. 1 is a schematic diagram illustrating an example of the overall configuration of a semiconductor manufacturing apparatus 1 according to the present embodiment. 2 is a cross-sectional view showing an example of the overall configuration of the reaction chamber 10 shown in FIG. 1, and FIG. 3 is an enlarged view of a main part of the susceptor 107 shown in FIG. In the present embodiment, a case where a φ200 mm wafer w made of silicon is used in the reaction chamber 10 will be described as an example, but the type of the wafer w to be used is not limited to this.

  As shown in FIG. 1, in a semiconductor manufacturing apparatus 1, a reaction chamber 10 that performs film formation processing of a wafer w and a wafer w and a later-described inner susceptor 107 c are connected to the reaction chamber 10 by a transfer robot 20 that is a transfer unit. A transfer chamber 30 for relaying the transfer is provided. In the transfer chamber 30, the wafer w and the inner susceptor 107 c are carried from the outside of the semiconductor manufacturing apparatus 1, and the IO module 50 provided for separating from the external atmosphere, and the inner susceptor storage 60 for storing the replacement inner susceptor 107 c ′. And a wafer standby chamber 70 for temporarily storing the wafer w retracted from the reaction chamber 10 during the film forming process.

  As shown in FIG. 2, the reaction chamber 10 is supplied with a source gas (for example, trichlorosilane, dichlorosilane, etc.) and a carrier gas such as hydrogen for forming an epitaxial film on the surface of the heated wafer w. A gas supply mechanism 101 for supplying the process gas is provided. In the upper part of the reaction chamber 10, gas supply ports 102 connected to the gas supply mechanism 101 are provided, for example, at two locations.

  Below the gas supply port 102, a number of discharge holes are formed, and a rectifying plate 103 that supplies the process gas supplied from the gas supply port 102 to the wafer w in a rectified state is provided.

  Below the reaction chamber 10, there is provided a motor (not shown), a cylindrical rotating ring 104a on which the susceptor 107 is placed, and a rotating shaft 104b, and a rotating unit 104 for rotating the wafer w. Yes. The rotating part 104 extends to the outside of the reaction chamber 10.

  As shown in FIG. 3, the susceptor 107 includes a first outer susceptor 107a, a second outer susceptor 107b, and an inner susceptor 107c. The first outer susceptor 107a has an opening larger than the inner susceptor 107c and smaller in diameter than the wafer w, and supports the peripheral portion of the wafer w. The second outer susceptor 107b is provided below the first outer susceptor 107a, and has an opening shielded by the inner susceptor 107c.

The diameter of the opening of the second outer susceptor 107b is smaller than the diameter of the opening of the first outer susceptor 107a through which the inner susceptor 107c passes when the push-up pin 108 is driven up and down. Moreover, the rotation ring 104a has a structure having an open top and a second outer susceptor 107b is shielded by the inner susceptor 107c, separated from the region of the reaction chamber 10 (hereinafter. Referred to _{P 1} region) area (hereinafter, referred to as _{P 2} region.) is formed in the rotating ring 104a. By separating the P ₂ region from the P ₁ region, it is possible to prevent the wafer w during the film formation process from being contaminated by the substance generated in the P ₂ region as the heater 109 is heated.

  The first outer susceptor 107a and the second outer susceptor 107b are formed in a ring shape, and each outer peripheral portion is connected to the upper portion of the rotating ring 104a. The inner susceptor 107c has a smaller diameter than the wafer w and is formed in accordance with the size and shape of the opening of the second outer susceptor 107b. As shown in FIGS. 2 and 3, the second outer susceptor 107 b is a position where a gap G is generated between the inner susceptor 107 c and the lower surface of the wafer w when the wafer w is supported by the first outer susceptor 107 a. Is arranged.

Further, the _{P 2} region, for example, a heater 109 for heating the wafer w made of SiC is provided. The heater 109 includes an in-heater 109a that heats the wafer w from the center, and an out-heater 109b that is provided between the in-heater 109a and the susceptor 107 and heats the outer periphery of the wafer w. A disk-shaped reflector (not shown) for efficiently heating the wafer w may be installed below the in-heater 109a. Furthermore, P in the ₂ area, push-up pins 108 to move the wafer w up and down through the inner susceptor 107c is installed to penetrate inner heater 109a, a reflector.

  In addition, a plurality of temperature measuring devices 110 such as a radiation thermometer that measures the in-plane temperature of the wafer w by radiation are installed in the upper part of the reaction chamber 10, and the temperature measuring devices 110 are temperature together with the in-heater 109a and the out-heater 109b. It is connected to the control mechanism 111. Moreover, the temperature measurement device 110 can measure the temperature by making the rectifying plate 103 and part of the upper wall surface of the reaction chamber 10 made of transparent quartz. In this embodiment, the temperature measuring device 110 has a distance from the center of the wafer w of 20 mm (hereinafter also referred to as an inner peripheral portion) and a point at 80 mm (hereinafter also referred to as an outer peripheral portion). Two fixed type devices that respectively measure the temperature of the wafer w are freely moved in the radial direction of the wafer w, and one movable type device that measures the temperature at an arbitrary point of the wafer w at a predetermined cycle is provided. The combination of the temperature measuring device 110 is not limited to this. For example, if more fixed type devices are installed, the movable type device does not need to be installed. The in-plane temperature distribution calculated from the temperature detected by such a temperature measuring device is an inner susceptor replacement parameter.

  In the lower part of the reaction chamber 10, gas exhaust ports 112 for exhausting exhaust gas containing excess process gas, reaction byproducts, and the like from the reaction chamber 10 are provided, for example, at two locations. The gas discharge port 112 is connected to a gas discharge mechanism 113 including a valve and a vacuum pump (not shown). Further, the semiconductor manufacturing apparatus 1 is provided with a control device 80 that is connected to the gas supply mechanism 101, the rotational drive control mechanism 106, the temperature control mechanism 111, the gas discharge mechanism 113, the transfer robot 20, and the like, and is controlled by a computer. . In addition, the control device 80 has a built-in storage device 90 in which the definition information of the correspondence relationship between the replacement inner susceptor 107c ′ and the in-plane temperature distribution of the wafer w obtained in advance through experiments or simulations is stored or connected thereto. Has been. The control device 80 refers to the definition information and selects the replacement inner susceptor 107c ′ to be used based on the in-plane temperature distribution calculated from the measured in-plane temperature. Then, after taking out from the inner susceptor storage 60, the transfer robot 20 and the push-up pin 108 are driven to control the exchange from the inner susceptor 107c to the replacement inner susceptor 107c ′. In addition, the timing for replacing the inner susceptor 107c is not limited to the time of the film forming process, and can be similarly implemented in the stage of preheating the wafer w, and the film uniformity is further promoted.

  4 is a top view showing a specific example of the wafer transfer hand 21 and the inner susceptor transfer hand 22 of the transfer robot 20 shown in FIG. As shown in the figure, the wafer placement portion of the wafer transfer hand 21 is formed in a C shape having a notch at the tip, and has a diameter substantially the same as the diameter r1 of the wafer w. Further, the susceptor mounting portion of the inner susceptor transfer hand 22 is formed in a C shape like the wafer transfer hand 21, but the diameter of the wafer w is adjusted to the diameter r2 of the inner susceptor 107c and the replacement inner susceptor 107c ′. It is formed smaller than r1. The transfer robot 20 can selectively carry in / out the wafer w and the inner susceptor 107c by switching the hand to be used based on a command from the control device 80.

  FIG. 5 is a view showing a specific example of the inner susceptor 107 c installed in the reaction chamber 10 shown in FIG. 1 and the replacement inner susceptor 107 c ′ stored in the inner susceptor storage 60. FIG. 6 is a diagram showing the relationship between the in-plane temperature (vertical axis) and the distance from the center (horizontal axis) of the wafer w shown in FIG. Here, in spite of the control by adjusting the output of the heater 109, the inner susceptor 107c for replacement is changed from the inner susceptor 107c shown in FIG. 5A when the temperature distribution of the wafer w exceeds a predetermined threshold. A specific example of adjusting the in-plane temperature distribution by exchanging with 'will be described. The wafer w on the inner susceptor 107c in FIG. 5A is heated, and the in-plane temperature of the wafer w is measured at a plurality of locations or moved in the radial direction by the temperature measuring device 110 and continuously measured. Assuming that the temperature distribution of five patterns A to E as shown in FIG. 6 is obtained from the temperature, the control device 80 determines as follows.

(1) In the case of the in-plane temperature distribution pattern of the straight line A Since the in-plane temperature is made uniform at 1100 ° C., which is a predetermined ultimate temperature, from the center of the wafer w to the end portion, the control device 80 performs in-plane by susceptor replacement. It is determined that temperature adjustment is unnecessary.

(2) In the case of the in-plane temperature distribution pattern of the broken line B Temperature distribution in which the in-plane temperature in the vicinity of 80 mm (outer peripheral portion) is higher than a predetermined reached temperature, with the maximum value at a position about 80 mm from the center of the wafer Therefore, when the temperature difference between the maximum value and the reached temperature exceeds a predetermined threshold, it is determined that the replacement inner susceptor 107c ′ as shown in FIG. That is, thinner than the thickness _{T b} is _{T a} bottom of 80mm near the center, since after replacement becomes wider the distance between the rear surface of the heating unit and the wafer w of the replacement inner susceptor 107C', 80mm vicinity of the (outer peripheral portion) The in-plane temperature can be locally lowered to make the temperature uniform.

(3) In the case of the in-plane temperature distribution pattern of the broken line C The in-plane temperature is made uniform from the center of the wafer w to the end portion, but the temperature difference from the predetermined reached temperature of 1100 ° C. is higher than the predetermined threshold value. If it is high as a whole, the control device 80 determines that it should be replaced with a replacement inner susceptor 107c ′ as shown in FIG. That is, the bottom thinner than the total thickness T _c is T _a, the interval between the rear surface of the heating unit and the wafer w replacement after replacement inner susceptor 107c' widens, reaching temperatures Overall lowered plane temperature Can be made uniform.

(4) In the case of the in-plane temperature distribution pattern of the alternate long and short dash line D The in-plane temperature in the vicinity of 80 mm is a temperature distribution lower than the predetermined attainment temperature, with the location at a distance of about 80 mm from the center of the wafer w being the minimum value. When the temperature difference between the minimum value and the reached temperature exceeds a predetermined threshold value, it is determined that the replacement inner susceptor 107c ′ as shown in FIG. That is, thicker than the thickness T _d is T _a bottom of 80mm near the center, after the replacement since the distance between the rear surface of the heating unit and the wafer w of the replacement inner susceptor 107c' in 80mm near the center is narrowed, the plane The temperature can be increased locally and uniformized at the ultimate temperature.

(5) In the case of the in-plane temperature distribution pattern of the two-dot chain line E The in-plane temperature is made uniform from the center of the wafer w to the outer periphery, but the temperature difference from 1100 ° C., which is the predetermined temperature, is a predetermined threshold value. If it is lower overall, the control device 80 determines that it should be replaced with a replacement inner susceptor 107c 'as shown in FIG. That is, the bottom thicker than the total thickness T _e is T _a, the interval between the rear surface of the heating unit and the wafer w replacement after replacement inner susceptor 107c' becomes narrow, arrival temperature generally increase the surface temperature Can be made uniform.

  The replacement inner susceptor 107c ′ stored in the inner susceptor storage 60 is not limited to the five types shown in FIG. For example, in contrast to the in-plane temperature distribution pattern indicated by the broken line B and the in-plane temperature distribution pattern indicated by the alternate long and short dash line D, the temperature error in the vicinity of about 20 mm (inner circumference) from the center of the wafer w is greater than a threshold (for example, ± 4 ° C. or more). In the case where the temperature error is less than the threshold value in the vicinity of about 80 mm, the inner susceptor 107c is prepared by reversing the positions where the irregularities are formed as shown in FIGS. This can be handled by storing the relationship in advance.

  Next, the semiconductor manufacturing method according to the present embodiment will be described with reference to the drawings. FIG. 7 is a flowchart showing a specific example of the semiconductor manufacturing method according to the first embodiment. FIG. 8 is a cross-sectional view for explaining how the wafer w is carried in / out, and FIG. 9 is a cross-sectional view for explaining how the inner susceptor 107c is carried in / out.

  First, the control device 80 drives the transfer robot 20 to introduce the wafer w into the reaction chamber 10 (S701). The push-up pins 108 are raised, and the introduced wafer w is placed on the inner susceptor 107c. At this time, the wafer w is first held at the apex of the convex portion formed on the upper surface of the inner susceptor 107c as shown in FIG. Since the atmospheric gas existing between the back surface of the wafer w and the top surface of the inner susceptor 107c escapes from the gap, the positional deviation of the wafer w is prevented. Subsequently, the push-up pin 108 is lowered based on the control by the control device 80, and the inner susceptor 107c separated from the wafer w is mounted so as to shield the opening of the second outer susceptor 107b, and the wafer w is attached to the inner susceptor. It is handed over from 107c to the 1st outer susceptor 107a, and is hold | maintained at a peripheral part (S702).

  Next, based on the in-plane temperature of the wafer w measured by the temperature measuring device 110, the temperature control mechanism 111 adjusts the output of the in-heater 109a and the out-heater 109b as appropriate within a range of 1400 to 1500 ° C., for example. The wafer w is heated through the wafer w so that the in-plane temperature of the wafer w is uniformly 1100 ° C., for example. The rotation drive control mechanism 106 rotates the rotating unit 104 to rotate the wafer w through the susceptor 107, for example, at 900 rpm.

Next, from the gas supply port 102, for example, carrier gas: H ₂ from ₂₀ to 100 SLM, source gas: SiHCl ₃ from 50 sccm to ₂ SLM, dopant gas: B ₂ H ₆ , PH ₃ : from a trace amount. Process gas is introduced, and the process gas is supplied onto the wafer w in a rectified state via the rectifying plate 103. At this time, the pressure in the reaction chamber 10 is controlled to, for example, 1333 Pa (10 Torr) to normal pressure by adjusting valves (not shown) of the gas supply mechanism 101 and the gas discharge mechanism 113, respectively. In this way, each condition is controlled, and a Si epitaxial film is formed on the wafer w (S703).

  In parallel with the formation of the Si epitaxial film, the temperature measuring device 110 measures the in-plane temperature of the wafer w during film formation at a plurality of points in the radial direction and outputs the measured temperature to the temperature control mechanism 111. The control device 80 connected to the temperature control mechanism 111 calculates the in-plane temperature distribution in-situ from the in-plane temperatures measured at a plurality of locations (S704).

  Next, the control device 80 analyzes the in-plane temperature distribution calculated in S704 and determines whether or not the temperature difference from the predetermined reached temperature is equal to or less than a predetermined threshold (S705). In spite of the adjustment by the output control of the heater 109, when the temperature difference exceeds a predetermined threshold value, it is necessary to adjust the in-plane temperature distribution, so it is determined that the inner susceptor 107c needs to be replaced.

  When it is determined that the temperature difference is equal to or smaller than the predetermined threshold (S705: Yes), the film forming process is continued up to the predetermined film thickness. On the other hand, when it is determined that the temperature difference exceeds the predetermined threshold (S705: No), the control device 80 stops the supply of the process gas by the gas supply mechanism 101 and the rotation unit 104 of the rotation drive control mechanism 106. The rotation is stopped and the formation of the Si epitaxial film is stopped (S706). As shown in FIG. 8, the wafer w is unloaded from the reaction chamber 10 by the wafer transfer hand 21 of the transfer robot 20 and temporarily retracted into the wafer standby chamber 70 (S707).

  Next, the control device 80 refers to the information that defines the replacement inner susceptor 107c ′ for each in-plane temperature distribution pattern of the wafer w, which is stored in advance in the storage device 90. Then, the replacement inner susceptor 107c ′ is selected from the inner susceptor storage 60 based on the in-plane temperature distribution calculated in S704 (S708). As shown in FIG. 9, the transfer robot 20 and the push-up pin 108 are driven to replace the existing inner susceptor 107c with the selected replacement inner susceptor 107c '(S709).

  Next, the control device 80 drives the wafer transfer hand 21 of the transfer robot 20 as shown in FIG. 8, and introduces the wafer w, which has been retreated into the wafer standby chamber 70 in S708, into the reaction chamber 10 again (S710). ). Then, the film forming process is resumed (S703).

  Then, a Si epitaxial film having a predetermined thickness is formed, the wafer w is unloaded from the reaction chamber 10 (S711), and the film forming process is completed. .

  As described above, according to the semiconductor manufacturing apparatus 1 according to the present embodiment, the in-plane temperature distribution of the wafer w is measured during the film forming process, and the replacement to the appropriate replacement inner susceptor 107c ′ is performed based on the distribution pattern. Can be implemented. In particular, when films having different compositions are laminated on the wafer w, it is effective because it is often difficult to make the in-plane temperature distribution uniform only by the output control of the heater 109 due to the occurrence of warpage. Further, since the in-plane temperature distribution can be adjusted with high accuracy without increasing the number of zones of the heater 109, the number of parts can be reduced and the manufacturing cost can be reduced.

<Embodiment 2>
In the second embodiment, another preferred embodiment will be described. In addition, since the code | symbol same as the code | symbol attached | subjected in the said Embodiment 1 represents the same object, description is abbreviate | omitted, and below demonstrates a different part in detail.

  In the present embodiment, the definition information stored in the storage device 90 is different from that in the first embodiment. Specifically, the storage device 90 preliminarily defines, as definition information, the correspondence between the replacement inner susceptor 107c ′ to be replaced with the inner susceptor 107c installed in the reaction chamber 10 and the type of film formed on the wafer w. Remember. This is because the in-plane temperature distribution varies depending on the type of film formed on the wafer w. For example, when forming a multilayer film in which the composition of the GaN-based compound semiconductor is varied, it is conceivable that warpage occurs due to variations in in-plane stress depending on the film type, and the in-plane temperature distribution varies.

  Further, when forming a multilayer film having a different composition of each layer on the wafer w, the control device 80 performs control to vary the mixing ratio of the process gas supplied from the gas supply mechanism 101. At this time, the control device 80 refers to the storage device 90 on the basis of the mixing ratio of the film type or the process gas that becomes the replacement parameter of the inner susceptor after switching, and sets the replacement inner susceptor 107c ′ in the inner susceptor storage unit 60. select.

  After temporarily stopping the process gas supply by the gas supply mechanism 101, the control device 80 drives the transfer robot 20 and the push-up pin 108, which are transfer units, and selects the inner susceptor 107c in the reaction chamber 10 based on the film type. Control is performed to replace the inner susceptor 107c ′ for replacement. Then, process gases having different mixing ratios are supplied onto the wafer w by the gas supply mechanism 101 to form layers of different film types.

  FIG. 10 is a flowchart showing a specific example of the semiconductor manufacturing method according to the second embodiment. First, the control device 80 drives the transfer robot 20 to introduce the wafer w into the reaction chamber 10 (S1001). As in the first embodiment, the wafer w introduced by raising the push-up pins 108 is placed on the inner susceptor 107c, and the push-up pins 108 are lowered to close the opening of the outer susceptor 107b. 1 is held at the peripheral edge of the outer susceptor 107a (S1002).

  Next, based on the in-plane temperature of the wafer w measured by the temperature measuring device 110, the temperature control mechanism 111 adjusts the output of the in-heater 109a and the out-heater 109b as appropriate within a range of 1400 to 1500 ° C., for example. The wafer w is heated through the wafer w so that the in-plane temperature of the wafer w is uniformly 1100 ° C., for example. The rotation drive control mechanism 106 rotates the rotating unit 104 to rotate the wafer w through the susceptor 107, for example, at 900 rpm.

Next, a process including, for example, a carrier gas: H ₂ of about 30 SLM, a group III source gas: NH ₃ of about ₃₀ SLM, and a Ga source gas: TMG of about 0.035 SLM from the gas supply port 102 by the gas supply mechanism 101. Gas is introduced, and process gas is supplied onto the wafer w in a rectified state via the rectifying plate 103. At this time, the pressure in the reaction chamber 10 is controlled to, for example, 1333 Pa (10 Torr) to normal pressure by adjusting valves (not shown) of the gas supply mechanism 101 and the gas discharge mechanism 113, respectively. In this way, each condition is controlled, and a GaN-based first layer is formed on the wafer w (S1003).

  Next, the control device 80 determines whether or not to switch the film type to be formed on the same wafer w by changing the mixing ratio of the process gas supplied from the gas supply mechanism 101 (S1004). Here, when it is determined not to switch the film type of the crystal film formed on the same wafer w (S1004: No), the film formation is continued up to a predetermined film thickness (S1003).

  On the other hand, when it is determined that the second layer is to be formed by switching the film type of the crystal film formed on the same wafer w (S1004: Yes), the control device 80 causes the gas supply mechanism 101 to change the process gas. The supply is stopped, and the rotation of the rotating unit 104 by the rotation drive control mechanism 106 is stopped to stop the formation of the GaN-based film (S1005). Next, as shown in FIG. 8, the wafer w is unloaded from the reaction chamber 10 by the wafer transfer hand 21 of the transfer robot 20 and temporarily retracted into the wafer standby chamber 70 (S1006).

  Next, the control device 80 refers to the information that defines the replacement inner susceptor 107c ′ for each film type or process gas mixing ratio stored in advance in the storage device 90. Then, the replacement inner susceptor 107c ′ is selected from the inner susceptor storage 60 based on the film type (S1007). Similarly to the first embodiment, as shown in FIG. 9, the transfer robot 20 and the push-up pin 108 are driven to replace the existing inner susceptor 107c with the selected replacement inner susceptor 107c ′ (S1008).

  Next, the control device 80 drives the wafer transfer hand 21 of the transfer robot 20 as shown in FIG. 8, and introduces the wafer w that has been retreated into the wafer standby chamber 70 in S1006 into the reaction chamber 10 again (S1009). ). Then, the film forming process is restarted, and a second layer composed of a film type having a composition different from that of the first layer is formed (S1003).

Then, a GaN-based film having a predetermined thickness is formed, the wafer w is unloaded from the reaction chamber 10 (S1010), and the film forming process is completed.

  As described above, according to the present embodiment, during the film forming process on the same wafer w, the in-plane temperature distribution of the wafer w is changed to the replacement inner susceptor 107c ′ corresponding to the film type to be formed on the wafer w. And a multilayer film having a different composition in each layer can be uniformly formed on the same wafer w.

<Modification>
As mentioned above, although several embodiment of this invention was explained in full detail, referring to a specific example, it is not limited to embodiment mentioned above, It can implement in various deformation | transformation in the range which does not deviate from another summary. .

  For example, when the film is formed on the same wafer w, in the first embodiment, the replacement is performed with the replacement inner susceptor 107c ′ selected with reference to the definition information based on the in-plane temperature distribution of the wafer w. In the second embodiment, the replacement inner susceptor 107c ′ is selected by referring to another definition information based on the film type. However, the configuration may be a combination of the first and second embodiments. That is, by storing the two types of definition information in the storage device 90, the replacement inner susceptor 107c ′ can be selected and replaced based on the in-plane temperature distribution and the film type. This is effective because it can cope with both the case where the in-plane temperature distribution changes greatly during the film formation process and the case where films having different components are stacked on the wafer w.

In the present embodiment, a single-layer Si epitaxial film formation or a GaN-based compound semiconductor has been described as an example, but other poly-Si layers, for example, insulating films such as SiO ₂ layers and Si ₃ N ₄ layers, It can be applied to a stack of compound semiconductors such as SiC, GaAlAs, and InGaAs. It can also be applied when changing the dopant of the semiconductor film.

w ... wafer, 1 ... semiconductor manufacturing apparatus, 10 ... reaction chamber, 20 ... transfer robot, 21 ... wafer transfer hand, 22 ... inner susceptor transfer hand, 30 ... transfer chamber, 40 ... wafer transfer robot, 50 ... IO module, 60 DESCRIPTION OF SYMBOLS ... Inner susceptor storage part, 70 ... Wafer waiting room, 80 ... Control apparatus, 90 ... Memory | storage device, 101 ... Gas supply mechanism, 102 ... Gas supply port, 103 ... Current plate, 104 ... Rotation part, 104a ... Rotation ring, 104b Rotating shaft 106 Rotation drive control mechanism 107 susceptor 107 a First outer susceptor 107 b Second outer susceptor 107 c Inner susceptor 107 c ′ Replacement inner susceptor 108 Push-up pin 109 ... heater, 109a ... in heater, 109b ... out heater, 110 ... temperature measurement Location, 111 ... temperature control mechanism, 112 ... gas outlet, 113 ... gas discharge mechanism.

Claims (5)

Store the replacement inner susceptor in the inner susceptor storage connected to the reaction chamber in advance,
Introducing the wafer into the reaction chamber;
The introduced wafer is placed on an inner susceptor loaded in advance,
The inner susceptor and the wafer are placed on an outer susceptor provided with an opening that is shielded by mounting the inner susceptor at a central portion,
Heating the wafer from below through the inner susceptor and the outer susceptor, supplying process gas onto the wafer in a rectified state from above and rotating the wafer to form a film on the wafer,
Select the replacement inner susceptor based on definition information defining the replacement parameter of the inner susceptor and the replacement inner susceptor in advance,
Temporarily stop the film formation on the wafer and replace the inner susceptor with the selected inner susceptor for replacement,
A method of manufacturing a semiconductor, comprising restarting film formation on the wafer.   The semiconductor manufacturing method according to claim 1, wherein the exchange parameter is an in-plane temperature distribution of the wafer, a film type to be formed, or a mixing ratio of the process gas. A reaction chamber into which the wafer is introduced;
A gas supply mechanism for supplying a process gas to the reaction chamber;
An inner susceptor having a diameter smaller than that of the wafer, and an outer susceptor provided with an opening shielded by mounting of the inner susceptor at a central portion, and a susceptor on which the wafer is placed;
A rotating unit that supports the outer periphery of the outer susceptor and rotates the wafer;
A heater provided in the rotating unit and heating the wafer from below via the susceptor;
A push-up pin provided in the rotating part for raising / lowering the inner susceptor;
A temperature measuring device provided in an upper part of the reaction chamber and measuring an in-plane temperature of the heated wafer;
An inner susceptor storage section for storing a replacement inner susceptor connected to the reaction chamber and exchanged for the inner susceptor;
A transport unit that carries in and out the inner susceptor and the replacement inner susceptor between the inner susceptor storage unit and the reaction chamber;
A storage device for preliminarily storing definition information defining a correspondence between the replacement parameter of the inner susceptor and the replacement inner susceptor;
A controller that calculates the in-plane temperature distribution from the in-plane temperature, selects the replacement inner susceptor based on the in-plane temperature distribution and the definition information, and instructs the replacement with the inner susceptor;
A semiconductor manufacturing apparatus comprising:   4. The semiconductor manufacturing apparatus according to claim 3, wherein the exchange parameter is an in-plane temperature distribution of the wafer, a film type to be formed, or a mixing ratio of the process gas. The transport unit is
A wafer transfer hand used when loading and unloading the wafer;
A susceptor transfer hand that is smaller than the wafer transfer hand and is used when the inner susceptor is loaded and unloaded;
The semiconductor manufacturing apparatus according to claim 3, wherein the semiconductor manufacturing apparatus comprises:

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