JPH06244116A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To uniform the heat treatment temperature for a semiconductor wafer in a reaction chamber, and improve the uniformity of film formation. CONSTITUTION:In the title equipment, a plurality of semiconductor wafers 8 are accommodated in a boat 9, and a thin film is formed on the surface of each semiconductor wafer 8. When the semiconductor wafers 8 are accommodated, according to the formation state of film thickness, in every other grove or every two or more grooves. Thereby generation of temperature difference in a furnace which is caused by close interval accommodation of the semiconductor wafers 8 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a semiconductor, and more particularly to a technique which is effective in a CVD apparatus or the like for uniformizing a heat treatment temperature in a reaction chamber.

[0002]

2. Description of the Related Art A CVD (Chemical Vapor Deposision) apparatus is known as an apparatus for depositing a thin film such as a silicon oxide film, a silicon nitride film, or a polycrystalline silicon film on the surface of a semiconductor wafer.

In this type of apparatus, a reaction chamber is heated by a heater, and a plurality of semiconductor wafers set in the thickness direction and on the same center line are inserted into a jig called a boat in the reaction chamber, and various kinds of processing required for processing are performed. CV by supplying the gas of
It is configured to perform D. In a CVD apparatus, one of important issues is how to form a film uniformly on a semiconductor wafer housed in a reaction chamber.

In the case of the vertical type, the reaction chamber is mainly composed of a cylindrical outer tube having a heater arranged on the outer periphery and a closed upper end, and an inner tube coaxially arranged in the outer tube. Is configured. Due to such a structure, the temperature of the lower portion having the opening for loading and unloading the semiconductor wafer is likely to be lower than that of other portions.

In order to solve this problem, for example, in Japanese Unexamined Patent Publication (Kokai) No. 3-46223, heaters are divided into a plurality of zones in the axial direction of the reaction chamber, and each of them is individually controlled for electric power (that is, heater heat generation). A technique has been proposed in which the amount is controlled so that the temperature in the lower part of the reaction chamber becomes high) to improve the film formation uniformity on the semiconductor wafer housed in the reaction chamber. Further, as disclosed in Japanese Patent Laid-Open No. 3-142823, a technique has been proposed in which a plurality of source gas introduction pipes and nozzles are provided to improve the uniformity of film formation.

[0006]

According to the study by the present inventor, in the prior art in which the heater is divided into a plurality of zones and the temperature is controlled, there is a limit in controlling the heat value of the heater. Since the heat treatment temperature of 1 changes, the variation of the characteristics cannot be avoided, and in the latter prior art, it is necessary to install a plurality of source gas introduction pipes.
There is a problem that the structure becomes complicated and maintainability is poor.

Therefore, an object of the present invention is to provide a technique capable of making the heat treatment temperature for the semiconductor wafer in the reaction chamber uniform and achieving the uniformity of film formation.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, a semiconductor manufacturing apparatus for accommodating a plurality of semiconductor wafers in a jig to form a thin film on each surface of the semiconductor wafer in a reaction chamber, wherein the semiconductor wafers are accommodated in the jig. Is arbitrarily set according to the film thickness formation state.

[0011]

According to the above-mentioned means, the temperature distribution when the semiconductor wafers are placed in the reaction chamber at regular intervals is grasped, and the storage interval of the semiconductor wafers in the jig is varied according to this temperature distribution. This makes it possible to reduce the variation in the film thickness on the surface of the semiconductor wafer and to make the film thickness uniform without causing a difference in the heat treatment temperature regardless of the storage position of the semiconductor wafer.

[0012]

1 is a front sectional view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention.

The reaction chamber 1 is cylindrical and has an outer tube 2 made of quartz glass, the upper part of which is closed and the lower end of which is open, and an outer wall of the outer tube 2, which is arranged coaxially with the outer tube 2. This is a vertical structure composed of the formed inner tube 3 made of quartz glass.

A heater 4 is arranged on the outer peripheral portion of the outer tube 2 so as to surround the outer tube 2, and is controlled by a controller (not shown). The outer pipe 2 and the inner pipe 3 are connected by a pedestal 5 at the lower end, and an exhaust port 6 is provided at the lower end of the void formed between the two pipes. Further, a gas supply pipe 7 for supplying the processing gas into the reaction chamber 1 is attached to the lower part of the connecting portion.

A boat 9 as a jig for accommodating the semiconductor wafer 8 to be processed is disposed below the reaction chamber 1. The boat 9 is attached to a boat elevator 10 which is driven up and down by a drive mechanism (not shown). Has been. Boat 9
Is composed mainly of four (or three) rod-shaped pillars,
Grooves (not shown) are provided inside the columns at regular intervals in the length direction, and the semiconductor wafer 8 is held by fitting the peripheral edge of the semiconductor wafer 8 into the grooves.

A wafer transfer machine 11 is installed adjacent to the boat elevator 10. This wafer transfer machine 11
Has an arm 12 for loading and unloading the semiconductor wafer 8 into and from the boat 9. This arm 12 is driven by the drive unit 13 attached to the wafer transfer machine 11.
It is configured to be freely movable in the horizontal direction and the vertical direction.

In the above structure, when a process of depositing an insulating film such as a silicon oxide film, a silicon nitride film or a polycrystalline silicon film on the surface of the semiconductor wafer 8 is performed, the wafer transfer machine 11 is operated to operate the wafer storage box. The semiconductor wafers 8 are taken out by the arm 12 and sequentially transferred into the boat 9, and a predetermined number of wafers are stored in the boat 9. When the transfer of the semiconductor wafer 8 to the boat 9 is completed, the gate at the lower end of the reaction chamber 1 is opened, the boat elevator 10 is driven, and the boat 9 is inserted into the reaction chamber 1.

The reaction chamber 1 is heated to a temperature required for processing by the heater 4, and a silicon oxide film, a silicon nitride film, a polycrystalline silicon film are formed on the surface of the semiconductor wafer 8 while supplying a processing gas from the gas supply pipe 7. An insulating film such as is deposited. At this time, the processing gas supplied from the gas supply pipe 7 ascends in the reaction chamber 1, reaches the upper end of the reaction chamber 1, and then descends through the gap between the outer pipe 2 and the inner pipe 3 from the exhaust port 6. It is discharged outside the reaction chamber.

When the desired processing is completed, the boat elevator 10 is driven to lower the boat 9 so that all of the semiconductor wafers 8 are pulled out from the reaction chamber 1, and after descending to a fixed position, the arm 12 is driven to drive the boat. 9 to semiconductor wafer 8
Are sequentially taken out.

In the semiconductor manufacturing apparatus configured as described above, when the semiconductor wafers 8 are accommodated in the boat 9 at regular intervals and are carried into the reaction chamber 1 as described above, film formation in the semiconductor wafer 8 is performed. Thickness uniformity is poor. Therefore, in the present invention, when the semiconductor wafer 8 is transferred to the boat 9 by the wafer transfer machine 11, the wafer storage interval 14 on the boat 9 is arbitrarily changed.

Specifically, the semiconductor wafers 8 are housed at intervals such that every other groove is provided in each of the columns of the boat 9 and every two grooves. In the upper part of the boat 9, the semiconductor wafers 8 are housed in a close space, and in the lower part of the boat 9 are housed in a sparse space to keep the temperature in the reaction chamber 1 uniform and to make the semiconductor wafers 8 uniform. The temperature inside the furnace is controlled to reach.

As a result, good results as shown in FIG. 2 were obtained. Here, the film flow rate, the in-plane variation, and the in-batch variation are compared with each other by keeping the gas flow rate, the reaction rate, and the pressure constant. The boat grooves are serially numbered from the upper side like "groove 1", "groove 2", ... "Groove 42". In the figure, the 1 × pitch corresponds to the conventional configuration, and the 2 × pitch corresponds to the present invention.

As is clear from FIG. 2, according to the present invention, the film forming rate, the in-plane variation, and the in-batch variation are all improved by making the pitch wide, and the manufacturing yield of LSI by the semiconductor wafer 8 is improved. It will be possible to improve. And, conventionally, it was necessary to control the temperature of the heater 4 for each zone, but this is not necessary.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above-mentioned embodiment, the case where the reaction chamber is vertical is illustrated, but the present invention can be similarly applied to the case where the reaction chamber is horizontal.

[0026]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

That is, a semiconductor manufacturing apparatus for accommodating a plurality of semiconductor wafers in a jig to form a thin film on each surface of the semiconductor wafer in a reaction chamber, wherein the semiconductor wafers are accommodated in the jig. Since the distance between the two is arbitrarily set according to the film thickness formation state, there is no difference in the heat treatment temperature regardless of the storage position of the semiconductor wafer,
It is possible to reduce variations in film thickness on the surface of the semiconductor wafer and to make the film thickness uniform. Therefore, LSI
It will be possible to improve the yield of semiconductor products such as.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing actual measurement results of wafer spacing dependency of film formation rate and film thickness variation of the present invention and the related art.

[Explanation of symbols]

 1 Reaction Chamber 2 Outer Tube 3 Inner Tube 4 Heater 5 Cradle 6 Exhaust Port 7 Gas Supply Pipe 8 Semiconductor Wafer 9 Boat 10 Boat Elevator 11 Wafer Transfer Machine 12 Arm 13 Drive Unit 14 Wafer Storage Interval

Claims (3)

[Claims] 1. A semiconductor manufacturing apparatus for accommodating a plurality of semiconductor wafers in a jig to form a thin film on each surface of the semiconductor wafer in a reaction chamber, wherein the semiconductor wafer is accommodated in the jig. The semiconductor manufacturing apparatus is characterized in that the interval between the two is arbitrarily set according to the formation state of the film thickness. 2. The storage space of the semiconductor wafer is such that a space is provided in a wafer storage groove provided at a constant interval in the length direction of the jig. Semiconductor manufacturing equipment. 3. The semiconductor manufacturing apparatus according to claim 1, wherein when the heater for heating the reaction chamber comprises a plurality of zones, the power consumption of each zone is the same.