JP2005259841A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus that can switch a material gas for a short time. <P>SOLUTION: The substrate processing apparatus is provided with a reaction tube 203 to house stacked semiconductor wafers 200, a heating source 207 installed outside the reaction tube 203, a gas supply tube 302 to introduce a gas into the reaction tube 203, and two gas exhaust tubes 303 and 311 to discharge the gas from the reaction tube 203. A gas jetting port 308 is provided opposite to the stacked wafers 200 in the gas supply tube 302, while a gas discharge port 309 is provided opposite to the stacked wafers 200 in the gas exhaust tube 303, and the gas discharge port is provided at a position where it is not opposite to the stacked wafers 200 in the gas exhaust tube 311. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus, and more particularly to a vertical vapor phase growth apparatus for simultaneously forming thin films on a plurality of semiconductor substrates.

As a technique for forming a thin film on a substrate surface in order to manufacture a semiconductor device, a CVD (Chemical Vapor Deposition) method has been generally used. However, with the miniaturization of semiconductor devices, the demand for forming thin films of various materials used in devices with high precision has increased, and in order to realize this, a technique called ALD (Atomic Layer Deposition) method has been developed. Application is in progress. The ALD method is a technique for forming a thin film by alternately switching a plurality of source gases serving as a thin film material and repeatedly supplying them to the substrate surface. However, in order to form a thin film with the thickness necessary for device application, it is necessary to switch gas several hundreds to thousands of times. Conventionally, from the point of process controllability, the substrates are processed one by one. Single-wafer type devices have been used. However, the single wafer system has a problem of low throughput, and in order to solve this problem, development of a batch system apparatus capable of batch processing several tens of substrates is required. At this time, in order to simultaneously and uniformly form a thin film on a plurality of substrates, it is necessary to uniformly supply the source gas supplied to the substrate inside the apparatus. On the other hand, for example, according to the vertical CVD apparatus disclosed in Japanese Patent Laid-Open No. 5-211122, it is shown that the gas concentration inside the apparatus can be made uniform.
JP-A-5-211122

  In the above conventional structure, since the exhaust pipe is smaller than that of the apparatus, it takes a relatively long time to reduce the pressure inside the apparatus, which has been raised by the supply of the raw material gas, to a predetermined pressure. In the ALD method, the process of supplying the next source gas after supplying one source gas and then exhausting the inside of the apparatus to a predetermined pressure is repeated hundreds to thousands of times. When applied to the ALD method, there is a problem that the time required for exhausting is remarkably increased and throughput is lowered particularly when the apparatus is enlarged due to an increase in the number of substrates or an increase in diameter.

  A main object of the present invention is to provide a substrate processing apparatus capable of switching source gases in a short time.

According to the present invention,
A container for storing the laminated substrates, a heating source installed outside the container, at least one gas supply pipe for introducing gas from the outside into the container, and a gas from the inside to the outside A substrate processing apparatus comprising at least two gas exhaust pipes for discharging
The gas supply pipe is installed so that one or more gas jets face the laminated substrate,
One of the at least two gas exhaust pipes is provided with one or more gas exhaust ports so as to face the laminated substrate,
A substrate processing apparatus is provided in which the other of the at least two gas exhaust pipes is provided at a position where a gas exhaust port does not face the stacked semiconductor substrate.

  Preferably, a cross-sectional area of the gas exhaust port installed so as to face the stacked substrate is smaller than a cross-sectional area of the gas exhaust port installed so as not to face the stacked substrate.

  Preferably, the sum of the cross-sectional areas of the gas exhaust ports installed so as to face the stacked substrates is the sum of the cross-sectional areas of the exhaust ports installed so as not to face the stacked substrates. Is also small.

  Moreover, according to this invention, the manufacturing method of the semiconductor device which manufactures a semiconductor device using the said substrate processing apparatus is provided.

Moreover, according to the present invention,
A container for housing the laminated semiconductor substrate, a heat source installed outside the container, one or more gas supply pipes for introducing gas from the outside into the container, and from the inside of the container to the outside A plurality of gas exhaust pipes for discharging gas to the
In the gas supply pipe, one or more gas outlets are installed so as to face the laminated semiconductor substrate,
At least one of the plurality of gas exhaust pipes is installed such that one or more gas exhaust ports are opposed to the stacked semiconductor substrates,
At least one of the plurality of gas exhaust pipes is a method for manufacturing a semiconductor device using a semiconductor substrate processing apparatus in which a gas exhaust port is installed at a position not facing the stacked semiconductor substrate. And
The first gas source gas is supplied from the gas supply pipe into the container, and the gas exhaust is installed such that the gas exhaust port of the plurality of gas exhaust pipes faces the stacked semiconductor substrate. Exhausting the first source gas from the tube;
The supply of the first source gas from the gas supply pipe to the inside of the container is stopped, and the gas exhaust port of the plurality of gas exhaust pipes is installed at a position not facing the stacked semiconductor substrate. There is provided a method for manufacturing a semiconductor device, wherein the step of exhausting the first source gas from the gas exhaust pipe is repeated up to the nth source gas (n is an integer).

  ADVANTAGE OF THE INVENTION According to this invention, the substrate processing apparatus which enables switching of source gas in a short time is provided.

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

FIG. 1 is a schematic longitudinal sectional view for explaining a processing furnace 202 of a vertical type vapor phase growth apparatus 10 which is a substrate processing apparatus according to a first embodiment of the present invention. FIG. 2 is a line AA in FIG. It is a cross-sectional view.
The processing furnace 202 of the vertical vapor phase growth apparatus 10 includes a quartz reaction tube 203, a quartz gas supply tube 302, a first gas exhaust pipe 303, a boat 217, and a boat installed inside the reaction tube 203. A rotation shaft 305 that rotates 217 is provided. A heating source 207 such as a heater is installed so as to surround the outside of the reaction tube 203. A plurality of semiconductor wafers 200 as substrates are stacked in a vertical direction on a predetermined position of the boat 217. The gas supply pipe 302 is provided with a plurality of gas ejection ports 108 at positions facing the wafers 200 stacked and mounted on the boat 217. The first gas exhaust pipe 303 is provided with a plurality of gas exhaust ports 109 at positions facing the wafers 200 stacked and mounted on the boat 217. The gas outlet 308 and the gas outlet 309 are installed so as to be positioned between the two wafers 200 mounted adjacent to the boat 217. Further, a cap 219 is provided at the lower part of the reaction tube 203, and a second gas exhaust pipe 311 is provided so as to be connected to the cap 219. The exhaust port 312 of the second gas exhaust pipe 311 is provided so as to open to the cap 219 and not to face the wafer 200 stacked and mounted on the boat 217. Here, the conductance or the like is adjusted so that the second gas exhaust pipe 311 has a higher exhaust capacity than the first gas exhaust pipe 303. Here, the gas exhaust port provided in the first gas exhaust pipe 303 is adjusted. The cross sectional area of the second gas exhaust pipe 311 is made larger than the sum of the cross sectional areas 108.

  Although not shown in the figure, the gas supply pipe 302 is connected to a gas supply system for transporting the source gas from the outside, and the first gas exhaust pipe 303 and the second gas exhaust pipe 311 are respectively connected to the gas supply system. It is connected to a gas exhaust system for exhausting the exhausted gas to the outside.

  A thin film forming method by the ALD method using two kinds of source gases when the processing furnace 202 of the vertical vapor phase growth apparatus 10 is used will be described.

  FIG. 3 shows the procedure of the thin film forming method. First, unnecessary gas existing in the reaction tube 203 is exhausted by the second gas exhaust tube 311 so that the pressure in the reaction tube 203 is adjusted to a predetermined pressure necessary for forming a thin film. Next, as the first source gas supply step, first, the exhaust through the second gas exhaust pipe 311 is stopped, the exhaust through the first gas exhaust pipe 303 is started, and then the first source gas is supplied to the gas supply pipe 302. When the supply is started, the first source gas is supplied from the gas outlet 308 provided in the gas supply pipe 302 to the wafer 200 loaded and mounted on the boat 217, and the first source gas is chemically applied to the surface of the wafer 200. A predetermined thin film is formed by adsorption. Thereafter, the first source gas passes through the space sandwiched between the wafers 200, reaches the gas exhaust port 309, and is exhausted to the outside through the first gas exhaust pipe 303.

  In the first raw material gas supply step, the following problem occurs when exhaust is performed by the second gas exhaust pipe 311 instead of the first gas exhaust pipe 303. 4 and 5 are schematic diagrams showing the gas flow state inside the reaction tube 203 when the exhaust through the first gas exhaust pipe 303 is stopped and the exhaust through the second gas exhaust pipe 311 is performed. At this time, a downward gas flow distribution is generated around the boat 217 from the gas outlet 308 toward the second gas exhaust pipe 311 as shown in FIG. As shown in FIG. 5, the supplied first source gas is drawn into the gas flow around the boat 217 and discharged from the outer peripheral side of the wafer 200. That is, the problem of insufficient supply of the source gas to the wafer 200 is caused, and the time required to form a thin film on the entire surface of the wafer 200 is prolonged. Therefore, when the source gas is supplied, the gas supply pipe 302 and the first gas exhaust pipe 303 are used in combination, so that the source gas introduced from one end of the surface of the wafer 200 is almost from one end opposite to the center of the wafer 200. Forming a gas flow that can be discharged is effective in reducing the process time.

  Next, an exhaust process of the first source gas remaining inside the reaction tube 203 performed before supplying the second source gas will be described. This is to prevent the reaction product generated by mixing and reacting the first and second source gases inside the reaction tube 203 from adhering to the substrate surface as foreign matter. First, the supply of the first source gas to the gas supply pipe 302 is stopped, then the exhaust through the first gas exhaust pipe 303 is stopped, and then the exhaust through the second gas exhaust pipe 311 is started.

  At this time, when only the first gas exhaust pipe 303 is used as it is for exhausting residual gas in the reaction tube 203 as it is, the shape thereof is an elongated pipe shape, so that the exhaust capability is insufficient and the exhaust time becomes long. In order to improve the exhaust capacity, it is conceivable to increase the gas conductance by increasing the cross-sectional area of the first gas exhaust pipe 303. However, this causes an increase in the shape of the exhaust pipe and the semiconductor growth apparatus. This is not preferable. In addition, since a large structure is disposed around the wafer 200, the distance between the heating source 207 installed outside the reaction tube 203 and the wafer 200 is increased, and the wafer 200 is heated to a predetermined temperature. This causes problems such as requiring more energy. On the other hand, when the second gas exhaust pipe 311 is used to exhaust the first source gas, a downward gas flow is generated around the boat 217, and the source gas present in the space sandwiched between the wafers 200 is Since it is quickly discharged from the entire outer peripheral side, it is effective for shortening the exhaust time.

  In the first raw material gas exhausting process, a large amount of the first raw material gas remains in the gas supply pipe 302 immediately after the supply of the first raw material gas is stopped. Exhaust is preferably continued until In addition, when the supply of the first raw material gas to the gas supply pipe 302 is stopped, the raw material gas remaining in the gas supply pipe 302 may be supplied by changing the raw material gas and supplying a gas that does not participate in the thin film formation. It is effective to discharge the water quickly.

  Next, when the exhaust of the first source gas is completed, the second source gas is supplied and exhausted in the same procedure. First, the exhaust by the second gas exhaust pipe 311 is stopped, the exhaust by the first gas exhaust pipe 303 is started, and the second raw material gas is supplied from the supply pipe 302 for a predetermined time, whereby the second raw material Gas is chemically adsorbed on the surface of the wafer 200 to form a predetermined thin film. Thereafter, the supply of the second source gas to the gas supply pipe 302 is stopped, the exhaust through the first gas exhaust pipe 303 is stopped, the exhaust through the second gas exhaust pipe 311 is performed, and the second gas inside the reaction pipe 302 is discharged. Discharge the source gas.

  By repeating the above steps a predetermined number of times, a thin film having a predetermined thickness can be formed on the substrate surface with high throughput.

In this embodiment, a structure of another vertical type vapor phase growth apparatus and a thin film forming method will be described.
6 is a schematic cross-sectional view for explaining a processing furnace of a vertical vapor phase growth apparatus which is a substrate processing apparatus according to a second embodiment of the present invention, and FIG. 7 is a vertical cross-sectional view taken along line CC in FIG. FIG.

  The processing furnace 202 of the vertical vapor phase growth apparatus 20 includes a quartz reaction tube 203, a quartz first gas supply pipe 351, a second gas supply pipe 352, and a first gas exhaust installed in the reaction tube 203. A pipe 303, a second gas exhaust pipe 311, a boat 217, and a rotating shaft 105 that rotates the boat 217 are provided. A heating source 207 such as a heater is installed so as to surround the outside of the reaction tube 203. A plurality of semiconductor wafers 200 as substrates are stacked in a vertical direction on a predetermined position of the boat 217. The first gas supply pipe 201 and the second gas supply pipe 202 are provided with a plurality of gas outlets 353 and gas outlets 354 at positions facing the wafers 200 stacked on the boat 217. The first gas exhaust pipe 303 is provided with a plurality of gas exhaust ports 309 in the wafer 200 stacked and mounted on the boat 217. The gas outlets 353 and 354 and the gas exhaust port 309 are installed so as to be positioned between the two wafers 200 mounted adjacent to the boat 217, respectively. Further, a cap 219 is provided at the lower part of the reaction tube 203. A second gas exhaust pipe 311 is provided on the lower side wall surface of the reaction tube 203. The exhaust port 312 of the second gas exhaust pipe 311 is provided in an opening on the lower side wall surface of the reaction tube 203 and is provided at a position not facing the wafer 200 stacked and mounted on the boat 217. Also in this case, the conductance or the like is adjusted so that the second gas exhaust pipe 311 has a higher exhaust capacity than the first gas exhaust pipe 303. Here, the gas exhaust provided in the first gas exhaust pipe 303 is adjusted. The sectional area of the second gas exhaust pipe 3111 was made larger than the sum of the sectional areas of the ports 309. This embodiment is different from the first embodiment described above in that a plurality of gas supply pipes 351 and 352 are provided, and a second gas exhaust port 311 is provided in the lower part of the side surface of the reaction pipe 203.

  Next, a method for forming a thin film by the ALD method using two kinds of source gases when the vertical vapor phase growth apparatus 20 is used will be described.

  FIG. 8 shows the procedure of the thin film forming method. First, unnecessary gas existing inside the reaction tube 203 is exhausted by the second gas exhaust tube 311, and the pressure inside the reaction tube 203 is adjusted to a predetermined pressure necessary for forming a thin film. Next, as the first source gas supply step, first, the exhaust by the second gas exhaust pipe 311 is stopped, the exhaust by the first gas exhaust pipe 303 is started, and then the first source gas is supplied to the first gas supply pipe 351. When the gas supply is started, the first source gas is supplied to the wafer 200 loaded on the boat 217 from the gas outlet 353 provided in the first gas supply pipe 351, and the first source gas is supplied to the surface of the wafer 200. A thin film is formed by chemisorption. Thereafter, the first source gas passes through the space sandwiched between the wafers 200, reaches the gas exhaust port 309, and is exhausted to the outside through the first gas exhaust pipe 303.

  Next, in order to exhaust the first raw material gas from the inside of the reaction tube 203, the supply of the first raw material gas to the first gas supply tube 351 is stopped, exhausted by the first gas exhaust tube 303, Exhaust by the gas exhaust pipe 311 is started.

  Next, the second source gas is supplied and exhausted in the same procedure. First, the exhaust by the second gas exhaust pipe 311 is stopped, the exhaust by the first gas exhaust pipe 303 is started, and then the supply of the second source gas to the second gas supply pipe 352 is started, whereby chemical adsorption is performed on the wafer 200 surface. Thus, a predetermined thin film is formed. Thereafter, the supply of the second raw material gas to the gas supply pipe 352 is stopped, the exhaust by the first gas exhaust pipe 303 is stopped, and the second gas exhaust pipe 311 is exhausted for a predetermined time to thereby react. The second source gas inside the tube 203 can be discharged to a predetermined pressure.

  By repeating the above steps a predetermined number of times, a thin film having a predetermined thickness can be formed on the substrate surface with high throughput.

  When the gas supply pipe to be used is changed depending on the type of the raw material gas to be supplied as described above, the raw material gases are not mixed inside the gas supply pipe, so generation of unnecessary reaction products can be prevented, and the quality can be improved. There is an advantage that an excellent substrate can be obtained. In addition, a plurality of gas exhaust pipes similar to the first gas exhaust pipe 303 of the present embodiment may be provided, and different exhaust pipes may be used depending on the supplied raw material gas. This is effective in that the generation of products can be prevented and clogging inside the piping of the gas exhaust system can be prevented.

  In the first and second embodiments of the present invention described above, in the vertical vapor phase growth apparatus, by providing a plurality of gas exhaust pipes for exhausting gas from the reaction tube, the source gas is sufficiently supplied to the substrate. Thus, it is possible to quickly discharge the raw material gas that is no longer needed.

  Next, an outline of a semiconductor manufacturing apparatus as an example of a substrate processing apparatus to which the present invention is suitably applied will be described with reference to FIGS.

  A cassette stage 105 is provided on the front side of the inside of the housing 101 as a holder transfer member that transfers the cassette 100 as a substrate storage container to and from an external transfer device (not shown). Is provided with a cassette elevator 115 as lifting means, and a cassette transfer machine 114 as a conveying means is attached to the cassette elevator 115. A cassette shelf 109 as a means for placing the cassette 100 is provided on the rear side of the cassette elevator 115, and a spare cassette shelf 110 is also provided above the cassette stage 105. A clean unit 118 is provided above the spare cassette shelf 110 so that clean air is circulated inside the housing 101.

  A processing furnace 202 is provided above the rear portion of the housing 101, and a boat 217 as a substrate holding unit that holds the wafers 200 as substrates in a horizontal posture in multiple stages is raised and lowered to the processing furnace 202 below the processing furnace 202. A boat elevator 121 as an elevating means is provided, and a seal cap 219 as a lid is attached to the tip of an elevating member 122 attached to the boat elevator 121 to support the boat 217 vertically. Between the boat elevator 121 and the cassette shelf 109, a transfer elevator 113 as an elevating means is provided, and a wafer transfer machine 112 as a transfer means is attached to the transfer elevator 113. Further, a furnace port shutter 116 as a shielding member having an opening / closing mechanism and closing the lower surface of the processing furnace 202 is provided beside the boat elevator 121.

  The cassette 100 loaded with the wafers 200 is loaded into the cassette stage 105 from an external transfer device (not shown) in an upward posture, and is rotated by 90 ° on the cassette stage 105 so that the wafer 200 is in a horizontal posture. Further, the cassette 100 is transported from the cassette stage 105 to the cassette shelf 109 or the standby cassette shelf 110 by cooperation of the raising / lowering operation of the cassette elevator 115, the transverse operation, the advance / retreat operation of the cassette transfer machine 114, and the rotation operation.

  The cassette shelf 109 has a transfer shelf 123 in which the cassette 100 to be transferred by the wafer transfer device 112 is stored. The cassette 100 to which the wafer 200 is transferred is transferred by the cassette elevator 115 and the cassette transfer device 114. Transferred to the transfer shelf 123.

  When the cassette 100 is transferred to the transfer shelf 123, the wafers 200 are transferred from the transfer shelf 123 to the boat 217 in a lowered state by the cooperation of the advance / retreat operation, the rotation operation, and the lifting / lowering operation of the transfer elevator 113. Is transferred.

  When a predetermined number of wafers 200 are transferred to the boat 217, the boat 217 is inserted into the processing furnace 202 by the boat elevator 121, and the processing furnace 202 is hermetically closed by the seal cap 219. In the processing furnace 202 that is hermetically closed, the wafer 200 is heated and a processing gas is supplied into the processing furnace 202 to process the wafer 200.

  When the processing on the wafer 200 is completed, the wafer 200 is transferred from the boat 217 to the cassette 100 of the transfer shelf 123 by the reverse procedure of the operation described above, and the cassette 100 is transferred from the transfer shelf 123 by the cassette transfer device 114. It is transferred to the cassette stage 105 and carried out of the housing 101 by an external transfer device (not shown). The furnace port shutter 116 closes the lower surface of the processing furnace 202 when the boat 217 is in the lowered state, and prevents outside air from being caught in the processing furnace 202.

  The transport operation of the cassette transfer machine 114 and the like is controlled by the transport control means 124.

It is a schematic longitudinal cross-sectional view for demonstrating the processing furnace of the vertical type vapor phase growth apparatus which is a substrate processing apparatus of the 1st Example of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is a procedure figure for demonstrating the thin film formation procedure by the vertical type vapor phase growth apparatus of 1st Example of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the gas flow state inside a reaction furnace when the position of an exhaust port is changed in the processing furnace of the vertical type vapor phase growth apparatus of 1st Example of this invention. FIG. 5 is a cross-sectional view taken along line BB in FIG. 4. It is a schematic cross-sectional view for demonstrating the processing furnace of the vertical type vapor phase growth apparatus which is a substrate processing apparatus of the 2nd Example of this invention. It is CC line longitudinal cross-sectional view of FIG. It is a flowchart for demonstrating the thin film formation procedure by the vertical type vapor phase growth apparatus of the 2nd Example of this invention. It is a schematic perspective view for demonstrating the substrate processing apparatus of Example 1 and 2 of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the substrate processing apparatus of Example 1 and 2 of this invention.

Explanation of symbols

10, 20 ... Vertical vapor phase growth apparatus 200 ... Substrate (wafer)
202 ... Processing furnace 203 ... Reaction tube 207 ... Heat source 217 ... Boat 219 ... Cap 302 ... Gas supply tube 303 ... First gas exhaust tube 305 ... Rotating shaft 308 ... Gas outlet 309 ... Gas exhaust port 311 ... Second gas exhaust Pipe 351 ... First gas supply pipe 352 ... Second gas supply pipe 353, 354 ... Gas outlet

Claims (1)

A container for storing the laminated substrates, a heating source installed outside the container, at least one gas supply pipe for introducing gas from the outside into the container, and a gas from the inside to the outside A substrate processing apparatus comprising at least two gas exhaust pipes for discharging
The gas supply pipe is installed so that one or more gas jets face the laminated substrate,
One of the at least two gas exhaust pipes is provided with one or more gas exhaust ports so as to face the laminated substrate,
A substrate processing apparatus, wherein a gas exhaust port is installed on the other of the at least two gas exhaust pipes so as not to face the laminated semiconductor substrate.

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