JP5134311B2 - 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 reaction gas to the front surface while heating from the back surface of a semiconductor wafer, for example.

  In recent years, with the miniaturization of semiconductor devices, high film thickness uniformity in a film forming process is required. In the film forming process, a CVD (Chemical Vapor Deposition) apparatus such as an epitaxial growth apparatus is generally used. In such a CVD apparatus, the backside heating method in which heating is performed from the backside has no heating source above, and the reaction gas used for film formation can be supplied on the wafer in the vertical direction from the same distance. Film formation is possible.

  In such a backside heating method, in order to obtain good film thickness uniformity, it is necessary to uniformly control the in-plane temperature of the wafer and supply the process gas uniformly onto the wafer. Therefore, it is considered that the gas flow can be supplied uniformly without being disturbed by convection or the like by rotating the wafer at a high speed and supplying the process gas as close as possible.

  However, since a gate for carrying in and out the wafer is provided on the side surface of the reaction furnace, a rectifying plate for supplying process gas to the wafer surface needs to be provided at a position higher than the gate in terms of structure. Therefore, it is difficult to lower the process gas supply position from the upper end of the gate, and the process gas supply position is higher than the gate part, so that the process gas flows into the gate part. Since the gate part is relatively low in temperature, reaction by-products are likely to adhere to it, and this accumulates and scatters, generating dust in the reaction furnace and reducing the yield of the semiconductor device. There is. Increasing the volume of the reaction furnace can suppress the adhesion of reaction by-products to the gate part to some extent, but it is not sufficient, and is not preferable for reducing the manufacturing cost and running cost of the apparatus.

On the other hand, in a single-wafer type heat treatment furnace, it has been proposed to adjust the height position of either the shower head unit or the holding base as necessary (see, for example, Patent Document 1). By adjusting the height position of the shower head and the like in this way, the process gas supply position can be made closer to the wafer, and the process gas can be supplied at a position lower than the gate portion. It is done. However, as shown in Patent Document 1, when the wafer is not simply driven up and down, but when the wafer is rotated at a high speed, there is a problem that the driving mechanism in the reaction furnace becomes complicated.
Japanese Patent Laid-Open No. 9-232297 (Claim 1, [0009], [0013], etc.)

  As described above, there is a problem in that it is difficult to bring the process gas supply position closer to the wafer and suppress the adhesion of reaction byproducts to the gate portion without complicating the drive mechanism in the reaction furnace. .

  The present invention provides a semiconductor manufacturing apparatus and a semiconductor manufacturing apparatus that can uniformly form a film on a wafer, reduce the amount of gas used, suppress the generation of dust in a reaction furnace, and suppress a decrease in yield. It is intended to provide a method.

The semiconductor manufacturing apparatus of the present invention, the reactor wafer is introduced, and a gas supply mechanism for supplying a process gas into the reaction furnace, and a gas discharge mechanism for discharging the process gas from the reaction furnace, reactor provided at a predetermined height position within, a holder for holding the wafer at the outer periphery thereof, a heater for heating from the bottom of the wafer, a rotating mechanism for rotating the wafer, the process gas on the wafer integrated with the current plate for supplying at commutation state, the wafer and the rectifying plate, in order to unload from the loading or the reactor into the reactor, and the gate can be opened and closed provided on the side of the reaction furnace, and the rectifying plate And holding the rectifying plate below the upper end of the gate, carrying it horizontally from the gate into the reactor and supporting it at a predetermined distance from the upper surface of the wafer. In, characterized in that and a conveying mechanism for conveying from the reaction furnace.

In the semiconductor manufacturing apparatus of the present invention, the transport mechanism, the wafer and the rectifying plate, is transported, respectively in the reaction furnace, it is preferable to carry-out from the reactor.

  In the semiconductor manufacturing apparatus of the present invention, the rectifying plate is preferably integrated with a transfer mechanism and a gate valve for opening and closing the gate.

  Furthermore, the semiconductor manufacturing apparatus of the present invention preferably includes a gas introduction mechanism for introducing the process gas onto the rectifying plate.

Further, in the semiconductor manufacturing method of the present invention, from the gate provided on the side surface of the reaction furnace, the wafer is carried into the reaction furnace by a transport mechanism, and on a holder installed at a predetermined height in the reaction furnace , placing the wafer, while the rectifier plate integrated with the transport mechanism and held at below the upper end of the gate, and carried horizontally from the gate to the reactor consists of the upper surface of the wafer with a predetermined distance The wafer is heated from below, the wafer is rotated, and a process gas is supplied onto the wafer through a current plate.

  By using the semiconductor manufacturing apparatus and the semiconductor manufacturing method of the present invention, a uniform film can be formed on the wafer, the amount of gas used can be reduced, the generation of dust in the reactor is suppressed, and the yield is suppressed. It becomes possible.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of the semiconductor manufacturing apparatus of this embodiment. As shown in the figure, in a reaction furnace 11 in which a wafer w is formed into a film, a gas supply port 13 for supplying a process gas onto the wafer w from above the reaction furnace 11 via a rectifying plate 12, and a reaction furnace 11 A gas discharge port 14 is provided for discharging process gas from below. Below the reaction furnace 11, a rotating mechanism 15 for rotating the wafer w and an annular holder 16 connected to the rotating mechanism 15 and holding the wafer w at the outer periphery thereof are installed. A gas introduction mechanism 17 for introducing a process gas into the rectifying plate 12 is provided above the reaction furnace 11.

  An in-heater 18a for heating the wafer w is installed below the holder 16, and an out-heater 18b for heating the peripheral edge of the wafer w is installed between the holder 16 and the in-heater 18a. The in-heater 18a and the out-heater 18b are controlled by a temperature control mechanism (not shown) based on the wafer temperature measured by a temperature measurement mechanism (not shown). A disc-shaped reflector 19 is installed below the in-heater 18a. Further, push-up pins 20 for lifting the wafer w are provided so as to penetrate the in-heater 17a and the reflector 19.

  On the side surface of the reaction furnace 11, a gate 21 for loading and unloading the wafer w and the current plate 12 is provided at a position higher than the holder 16. The wafer w and the rectifying plate 12 are carried in and out via the gate 21 by a transfer mechanism 22 provided in an adjacent transfer chamber (not shown). The transfer mechanism 22 includes a transfer arm 22a for the wafer w and a transfer arm 22b for the rectifying plate 12, and the transfer arm 22b is integrated with the rectifying plate 12 and a gate valve 23 for opening and closing the gate.

  For example, a Si epitaxial film is formed on the wafer w using such a semiconductor manufacturing apparatus. First, for example, as shown in a conceptual diagram of the film forming unit in FIG. 3, a 12-inch wafer w is carried into the transfer chamber 33 from the accommodated cassette 31 through the load lock unit 32 by the transfer arm 22a. Then, it is carried into the reaction furnace 11 from the gate 21 by the transfer arm 22 a and placed on the push-up pin 20. Then, the push-up pins 20 are lowered to hold the wafer w in the holder 16.

  Then, as shown in FIG. 2, the rectifying plate 12 integrated with the transfer arm 22b is carried into the reaction furnace 11, and the rectifying plate 12 is separated from the wafer w, for example, by a distance of 20 mm as necessary. Thus, the transport mechanism 22 is moved up and down. Then, the gate 21 is closed by the integrated gate valve 23.

  Next, based on the temperature of the wafer w measured by a temperature measurement mechanism (not shown), the temperature of the in-heater 18a and the out-heater 18b is appropriately controlled within a range of, for example, 1400 to 1500 ° C. by a temperature control mechanism (not shown). By doing so, the temperature of the wafer w is controlled to be uniformly 1100 ° C., for example, within the surface. Further, the wafer w is rotated by, for example, 900 rpm by the rotation mechanism 15.

From the gas supply port 13, for example, a process gas consisting of ₂₀ to 100 SLM of carrier gas: H ₂ , 50 sccm to ₂ SLM of film forming gas: SiHCl ₃ , dopant gas: B ₂ H ₆ , PH ₃ : trace amount reacts. It is supplied into the furnace 11. Further, the gas is introduced onto the rectifying plate 12 by the gas introduction mechanism 17 and supplied onto the wafer w in a rectified state. At this time, the pressure in the reaction furnace 11 is controlled to, for example, 1333 Pa (10 Torr) to normal pressure by adjusting the valves of the gas supply port 13 and the gas discharge port 14. In this way, each condition is controlled, and an epitaxial film is formed on the wafer w.

  In this way, the process gas can be supplied onto the wafer while maintaining the rectification state by rotating the wafer at a high speed and bringing the rectification plate closer to the wafer, so that the process gas is uniformly supplied within the wafer surface. The As a result, it is possible to form a uniform epitaxial film having a thickness variation of 0.5% or less on the wafer, for example. Further, since the distance between the rectifying plate and the wafer is short, the gas does not spread laterally and flows on the wafer without waste, the gas reaction efficiency is increased, and the amount of gas used can be reduced. In addition, since the wafer deposition position (holder position) can be set lower than the gate, it is possible to improve the yield of the wafer by suppressing the adhesion of reaction by-products to the gate and the generation of dust. Become.

  Then, when a semiconductor device is formed through an element formation process and an element isolation process, it is possible to suppress variation in element characteristics and improve yield. In particular, an epitaxial formation process of a power semiconductor device such as a power MOSFET or IGBT (insulated gate bipolar transistor) that requires a thick film growth of several tens to 100 μm in an N-type base region, a P-type base region, an insulating isolation region, or the like. As a result, good device characteristics can be obtained.

(Embodiment 2)
FIG. 4 shows a cross-sectional view of the semiconductor manufacturing apparatus of this embodiment. As shown in the figure, the configuration is almost the same as in the first embodiment, but the rectifying plate 41 and the gate valve 42 are independent, and are not integrated with the transfer arm 43a of the transfer mechanism 43, the wafer w And the rectifying plate 41 are different from each other in that the conveying arm 43 a is used in common and the rectifying plate 41 is held by a pin 44 installed on the holder 16.

  As in the first embodiment, after the wafer w is held on the holder 16, the current plate 41 is carried into the reaction furnace 11 by the transfer arm 43 a, and on the current plate holding pins 44 installed on the holder 16. Placed and held on. Next, the gate 21 is closed by the gate valve 42 and each condition is controlled as in the first embodiment, and an epitaxial film is formed on the wafer w.

  In this way, by forming the epitaxial film on the wafer, the same effect as in the first embodiment can be obtained. Further, unlike the first embodiment, since the transfer arm for the wafer and the current plate is made common, it is possible to reduce the number of parts and simplify the transfer control system.

  In these embodiments, after the current plate is unloaded from the reaction furnace, the wafer w is unloaded from the reaction furnace. At this time, the discharged current plate may be cleaned. By cleaning, reaction by-products attached to the current plate can be removed, dust generation can be suppressed, yield can be improved, and cleaning frequency in the reactor can be reduced. Therefore, it is possible to improve the operation rate. Then, as shown in the conceptual diagram of the film forming unit in FIG. 5, by providing the cleaning unit 51 adjacent to the transfer chamber 33, cleaning can be performed in the film forming unit, and the operating rate is further improved. It becomes possible.

  Further, the gas introduction mechanism for introducing the process gas into the rectifying plate is not limited to the shape as shown in FIG. 1, and for example, a gas introduction mechanism 61 as shown in FIG. 6 can be used. Further, as shown in FIG. 7, a ring-shaped protrusion 72 may be provided on the rectifying plate 71 side and connected to the gas introduction mechanism 73. Such a gas introduction mechanism may be further driven by providing a vertical drive mechanism (not shown).

In the above-described examples, the case of forming the Si single crystal layer (epitaxial growth layer) 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 other compound semiconductors such as a GaAs layer, GaAlAs, InGaAs, and the like. Further, the present invention can be applied to the case of forming a SiO ₂ film or a Si ₃ N ₄ film. In the case of a SiO ₂ film, in addition to monosilane (SiH ₄ ), N ₂ , O ₂ , and Ar gas are used as the Si ₃ N ₄ film. In this case, NH ₃ , N ₂ , O ₂ , Ar gas and the like are supplied in addition to monosilane (SiH ₄ ). Various other modifications can be made without departing from the scope of the invention.

1 is a cross-sectional view of a semiconductor manufacturing apparatus in one embodiment of the present invention. 1 is a cross-sectional view of a semiconductor manufacturing apparatus in one embodiment of the present invention. 1 is a conceptual diagram of a film formation unit in one embodiment of the present invention. 1 is a cross-sectional view of a semiconductor manufacturing apparatus in one embodiment of the present invention. 1 is a conceptual diagram of a film formation unit in one embodiment of the present invention. 1 is a cross-sectional view of a semiconductor manufacturing apparatus in one embodiment of the present invention. 1 is a cross-sectional view of a semiconductor manufacturing apparatus in one embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Reactor, 12, 41, 71 ... Rectification plate, 13 ... Gas supply port, 14 ... Gas discharge port, 15 ... Rotation mechanism, 16 ... Holder, 17, 61, 73 ... Gas introduction mechanism, 18a ... Inheater, 18b ... outheater, 19 ... reflector, 20 ... push-up pin, 21 ... gate, 22, 43 ... transport mechanism, 22a, 22b, 43a ... transport arm, 23,42 ... gate valve, 31 ... cassette, 32 ... load lock unit, 33 ... Conveying chamber, 44 ... Rectifying plate holding pin, 51 ... Cleaning unit, 72 ... Protrusion.

Claims (5)

A reactor into which the wafer is introduced;
A gas supply mechanism for supplying a process gas into the reaction furnace,
A gas discharge mechanism for discharging the process gas from the reactor;
A holder provided at a predetermined height in the reactor, and a holder for holding the wafer at an outer periphery thereof;
A heater for heating the wafer from below;
A rotation mechanism for rotating the wafer;
A rectifying plate for supplying the process gas on the wafer in a rectified state ;
An openable and closable gate provided on a side surface of the reaction furnace in order to carry the wafer and the rectifying plate into or out of the reaction furnace ;
A position that is integrated with the current plate, is held at a position lower than the upper end of the gate, and is horizontally introduced from the gate into the reactor and is at a predetermined distance from the upper surface of the wafer. And a transport mechanism for unloading from the reactor,
A semiconductor manufacturing apparatus comprising: The transport mechanism, the wafer and the current plate is transported to each of the reaction furnace, a semiconductor manufacturing apparatus according to claim 1, characterized in that unloading from the reactor.   3. The semiconductor manufacturing apparatus according to claim 1, wherein the rectifying plate is integrated with a gate valve for opening and closing the transfer mechanism and the gate.   The semiconductor manufacturing apparatus according to any one of claims 1 to 3, further comprising a gas introduction mechanism for introducing the process gas onto the rectifying plate. From the gate provided on the side of the reaction furnace, the wafer is carried into the reaction furnace by a transfer mechanism ,
Place the wafer on a holder installed at a predetermined height in the reactor,
While maintaining the rectifying plate that is integrated with the transport mechanism below the upper end of the gate, and carried horizontally from the gate to the reactor, so that a predetermined distance from the upper surface of the wafer Installed in
Heating the wafer from below,
Rotate the wafer,
A semiconductor manufacturing method, wherein a process gas is supplied onto the wafer through the current plate.

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