JPH03243777A - Semiconductor producing device - Google Patents

Abstract

PURPOSE:To form a desired film while controlling the growth of a naturally oxidized film on the surface of a substrate by providing an etching chamber and a wafer transfer machine in a load locking chamber and introducing the semiconductor substrate into a reaction tube in an N2 atmosphere. CONSTITUTION:This semiconductor producing device is formed by a reaction tube 1, a load locking chamber 3, an etching chamber 14 and a device 20 for conveying a semiconductor substrate 5 to the reaction tube 1. A raw gas 10 for forming a film on the surface of the substrate 5 is introduced into the reaction tube 1. The partial pressure of oxygen in the atmosphere is controlled by the load locking chamber 3 when the substrate 5 is inserted into the reaction tube 1. The etching chamber 14 is provided in the load locking chamber 3, and the semiconductor oxide film on the surface of the substrate 5 is etched.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to semiconductor manufacturing equipment, particularly semiconductor substrates (for example, S
This invention relates to improvements in semiconductor manufacturing equipment for forming films such as dielectric films and polysilicon films on the surface of i-substrates.

[Conventional technology]

Figure 2 shows, for example, in conventional semiconductor manufacturing equipment, especially LP.
GVD device (Low Pressure Chemical
FIG. In the figure, 1 is a reaction tube for forming a film, 2 is a heater that heats the reaction tube 1 and the inside of the reaction tube 1, 3 is a load lock chamber that supports this heater 2, and 4 is a door of the load lock chamber. 5 is a semiconductor substrate, for example a Si wafer, which is held in a quartz boat 6.

7 is a cap that supports the quartz boat 6, and is moved up and down by the elevator 8, and the cap 7 supports the quartz boat 6.
The wafer 5 can be inserted into the reaction tube 1 . Reference numeral 9 denotes a reaction gas exhaust system with a built-in pump, which exhausts air and reaction gas, such as SiH4, from inside the reaction tube 1. 10
is a reaction gas supply system for supplying reaction gas into the reaction tube 1.

Reference numeral 11 denotes a flange, which is fixed to the upper part of the load-lock chamber 3 so that the quartz boat 6 supporting the Si wafer 5 can pass through the opening 11a.

With the above configuration, the cap 7 is raised by the elevator 8 and closes the opening 11a of the flange 11, thereby causing the reaction tube 1. Flange 11. The cap 7 constitutes a vacuum container. Further, with the opening portion 11a open, the reaction tube 1. Load lock chamber 3. Door 4. The flange 11 is the vacuum container 12
The internal air can be exhausted by the load lock chamber exhaust system 13.

In addition, the inside of the reaction tube 1 is kept at a high temperature by the heater 2, for example, 6
The temperature is maintained at 00°C.

Next, steps for forming a polysilicon film on a Si wafer using the above conventional apparatus will be explained in order.

(2) After etching the silicon oxide film on the surface of the Si wafer 5 with, for example, a hydrochloric acid solution, the door 4 is opened and the Si wafer 5 is placed on the quartz boat 6 in the load lock chamber 3. At this time, the cap 7 is lowered and the quartz boat 6 is outside the reaction tube 1.

■ After closing the door 4 and exhausting the air inside the vacuum container 12 using the load lock exhaust system 13, the reaction gas supply system 9
N2 gas is supplied to replace the inside of the vacuum container 12 with N2.

■ Raise the cap 7 using the elevator 8 and
After inserting the wafer 5 into the reaction tube 1, the camp 7 closes the opening 11a.

■ After evacuating the inside of the reaction tube 1 using the reaction gas exhaust system 9, SiH and gas are supplied from the reaction gas supply system 10, and S
A polysilicon film is formed on the surface of i-wafer 5.

(2) After film formation, the reacted SiHa gas in the reaction tube 1 is exhausted by the reaction gas exhaust system 9, and the cap 7 is lowered while supplying N3 gas from the reaction gas supply system 10.

(2) The camp 7 is lowered and the inside of the vacuum container 12 is returned to atmospheric pressure by the N8 gas supplied from the reaction gas supply system 10. Then, the door 4 is opened and the Si wafer 5 is taken out.

[Problem to be solved by the invention]

The conventional LPGVD device is configured as described above.
The Si wafer 5 is inserted into the high temperature reaction tube 1, and the Si wafer 5 is
Until the H, gas is thermally decomposed and a polysilicon film is formed on the surface of the Si wafer 5 (the above steps
Since the i-wafer 5 is surrounded by an N2 or 5iHn atmosphere, no new silicon oxide film is formed on the surface of the Si wafer 5.

However, until the Si wafer 5 from which the natural oxide film has been removed in the above step (3) is placed on the quartz boat 6 in the load lock chamber 3 and the inside of the vacuum chamber 12 is replaced with N, the Si wafer 5 is
is exposed to air, so during this time Si
Formation of a natural oxide film on the surface of the wafer 5 was unavoidable.

When a polysilicon film is formed on the surface of the Si wafer 5 in the presence of the natural oxide film, the electrical resistance between the Si wafer and the polysilicon film increases due to the natural oxide film interposed between them. Sometimes it becomes insulated. This poses a problem in that the operation of the semiconductor device is hindered.

This invention was made to solve the above-mentioned problems, and a natural oxide film is generated on the surface of the Si wafer between the time the natural oxide film is removed and the film is formed on the surface of the Si wafer. It is an object of the present invention to obtain a semiconductor manufacturing apparatus that can suppress this.

[Means to solve the problem]

A semiconductor manufacturing apparatus according to the present invention includes an etching chamber for etching a natural oxide film on the surface of a semiconductor substrate and a transfer machine for transferring a wafer from the etching chamber to a reaction tube in a load lock chamber. It is something that

[Effect]

In this invention, an etching chamber and a wafer transfer machine are provided in the load lock chamber, so that after removing the natural oxide film on the surface of the semiconductor substrate, the semiconductor substrate is subjected to reaction in an N8 atmosphere without being exposed to air. It can be introduced into a tube, and a film can be formed while suppressing the growth of a native oxide film on the surface of a semiconductor substrate.

〔Example〕

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

FIG. 1 is a schematic configuration diagram of a semiconductor manufacturing apparatus according to an embodiment of the present invention, in which the same reference numerals as in FIG. 2 indicate the same or corresponding parts, and 7 is a cap that supports a quartz boat 6;
It is moved up and down by elevator 8 or 19. 14 is Si
An etching chamber for removing the natural oxide film on the surface of the wafer 5; 15 is an etching gas supply system for supplying gas for etching the natural oxide film, such as HF gas, into the etching chamber 14; 16 is an etching gas supply system for the etching chamber 14; This is an etching gas exhaust system to exhaust gas and air inside. Reference numeral 18 denotes a transfer, on which the cap 7 supporting the quartz boat 6 is placed, and which moves on a rail 17 grounded in the load rotor chamber. The transfer 18 and the rail I7 constitute a wafer transfer device 20 for transporting the Si wafer 5 from the etching chamber 14 to the reaction tube 1.

Next, steps for forming a polysilicon film on a Si wafer using the apparatus of this embodiment will be explained in order.

(2) In FIG. 1(a), the door 4 is opened and the Si wafer 5 is placed on the quartz boat 6 on the cap 7 supported by the elevator 19. At this time, the cap 7 is lowered and the quartz boat 6 is outside the etching chamber 14.

■ Close door 4 and load lock chamber 3. After exhausting the air inside the vacuum container 12, which is composed of the door 4° flange 111 and the reaction tube 1, using the load rotor exhaust system 13, the inside of the vacuum container 12 is pumped by supplying nitrogen and gas from the reaction gas supply system 9. N.

Replace.

■ Raise the cap 7 using the elevator 19 and
The i-wafer 5 is introduced into the etching chamber 14, and the cap 7 is removed.
Close the etching chamber with .

(2) By supplying HF gas into the etching chamber 14 from the etching gas supply system 15, the silicon oxide film on the surface of the Si wafer 5 in the etching chamber 14 is removed.

■ The remaining HF gas in the etching chamber 14 is exhausted using the etching gas exhaust system 16, and the etching gas supply system 1
Nt is replaced by supplying N2 gas from step 5.

■ Use the elevator 19 to lower the cap 7, the quartz boat 6 on top of it, and the Si wafer 5, and
The quartz boat 6 carrying the wafer 5 and the cap 7 are transferred to the transfer 18.

■ Move Transfer 18 with Camp 7 to Rail 1
7 to just below the reaction tube 1 (Fig. 1 (bl)
reference).

(2) After passing the cap 7 to the elevator 8, the cap 7 is raised by the elevator 8, and the Si wafer 5 and the quartz boat 6 are guided into the reaction tube 1.

After closing the opening 11a with the cap 7, the inside of the reaction tube 1 is evacuated using the reaction gas exhaust system 9, and 5iHn gas is supplied from the reaction gas supply system 10 to deposit polysilicon on the surface of the Si wafer 5. Forms a film.

[Phase] After film formation, SiH and gas in the reaction tube 1 are exhausted by the reaction gas exhaust system 9, and N, gas is exhausted from the reaction gas supply system 10.
The cap 7 is lowered while supplying gas.

■ Transfer cap 7 from elevator 8 to transfer 1-18.
After being transferred to, the transfer 18 is moved along the rail 17 to the vicinity of the door 4.

@ Open door 4 and go from quartz boat 6 to camp 7
Take out i-wafer 5.

As described above, according to this embodiment, in the load lock chamber 3,
Since the etching chamber 4 and the transfer device 20 for the wafer 5 are provided, after removing the natural oxide film on the surface of the semiconductor substrate 5, the semiconductor substrate 5 is transferred into the reaction tube 1 under N atmosphere without exposing it to air. A desired film can be formed while suppressing the growth of a native oxide film on the surface of the semiconductor substrate 5.

〔Effect of the invention〕

As described above, according to the semiconductor manufacturing apparatus according to the present invention, the natural oxide film on the surface of the Si wafer is removed by etching in the etching chamber provided in the load lock chamber, and the Si wafer after etching is introduced into the reaction tube. A wafer transfer device was installed in the load lock chamber to carry out this process, so the Si wafer surface from which the silicon oxide film had been removed was introduced into the reaction tube without being exposed to the atmosphere, and the S
It is possible to form a film on the i-wafer surface, and as a result, S
The electrical resistance between the i-wafer and the film formed on its surface can be stably lowered, and the performance and yield of semiconductor devices can be improved.

[Brief explanation of drawings]

FIGS. 1A to 1C are schematic configuration diagrams for explaining the configuration and operation of a semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a conventional semiconductor manufacturing apparatus. DESCRIPTION OF SYMBOLS 1... Reaction tube, 2... Heater, 3... Load lock chamber, 4... Door, 5... Semiconductor substrate, 6... Quartz boat, 7... Cap, 8...・Ereheta, 9
... Reaction gas exhaust system, 10 ... Reaction gas supply system, 1
DESCRIPTION OF SYMBOLS 1...Flange, 12...Vacuum container, 13...Load lock chamber exhaust system, 14...Etching chamber, 15...
...Etching gas supply system, 16...Etching gas exhaust system, 17...Rail, 18...Transfer 19...Electrical heater, 20...Wafer transfer machine. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A reaction tube for introducing raw material gas for forming a film on the surface of a semiconductor substrate, a load lock chamber for controlling oxygen partial pressure in the atmosphere when inserting the semiconductor substrate into the reaction tube, and the load. 1. A semiconductor manufacturing apparatus comprising, within a lock chamber, an etching chamber for etching the semiconductor oxide film on the surface of the semiconductor substrate, and a device for transporting the semiconductor substrate from the etching chamber to a reaction tube.