JPH05283348A - Longitudinal cvd device - Google Patents

Abstract

(57) [Summary] [Purpose] In a vertical CVD apparatus, a wafer is processed during a cleaning process and a CVD process without being exposed to the atmosphere. A wafer cleaning unit 17 is provided in a load lock chamber 2 provided below a vertical reaction chamber 1 with a buffer chamber 10 provided in an airtight manner, and a wafer process, a pre-process or a post-process of the wafer process. The wafer cleaning process is carried out while cleaning and maintaining the airtight state of the wafer to prevent natural oxidation of the wafer and contamination by dust.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical CVD apparatus which is one of semiconductor manufacturing apparatuses, and more particularly to a vertical CVD apparatus having a load lock chamber.

[0002]

2. Description of the Related Art There is a method of forming a thin film on the surface of a silicon wafer by chemical vapor deposition (CVD), and a vertical CVD apparatus is used for forming this thin film.

A conventional vertical CVD apparatus will be described with reference to FIG.

A load lock chamber 2 is provided below the vertical reaction chamber 1, and a cassette chamber 4 is hermetically provided in the load lock chamber 2 through a gate valve 3, and a cassette loading / unloading port of the cassette chamber 4 is provided. Is hermetically closed by the gate valve 5.

A boat elevator 6 is provided inside the load lock chamber 2 and below the vertical reaction chamber 1.
The boat elevator 6 loads and unloads a boat (not shown) holding wafers (not shown) in multiple stages into the vertical reaction chamber 1. Further, inside the load lock chamber 2, there is provided a wafer transfer machine 7 for transferring between the cassette chamber 4 and the boat. The cassette chamber 4
Is designed to carry in and carry out the cassette 8 in which a required number of wafers are loaded. Further, the load lock chamber 2,
The cassette chamber 4 is provided with a gas supply / exhaust device (not shown) for evacuating the interior or supplying an inert gas such as nitrogen gas.

In the wafer processing step, there is a cleaning of the wafer as a pre-processing step, and a post-processing cleaning step is provided for the processing in which the reaction continues due to residual gas after the processing. In the CVD apparatus, every time cleaning is performed, the wafer loaded in the cassette is taken out from the cassette chamber 4, the wafer is cleaned, and then the wafer is loaded into the cassette chamber 4 to continue the processing.

[0007]

However, in the conventional vertical CVD apparatus, since the wafer is once taken out of the apparatus after each cleaning step, the wafer is exposed to the atmosphere, causing natural oxidation of the wafer, or There is a problem that the wafer is contaminated by dust.

In view of the above situation, the present invention is designed so that the apparatus is not taken out from the sealed apparatus until a series of processing is completed.

[0009]

SUMMARY OF THE INVENTION The present invention is characterized in that a wafer cleaning unit is provided in a load lock chamber provided below a vertical reaction chamber with an airtight buffer chamber interposed. is there.

[0010]

The wafer process, the pre-process and the post-process cleaning process of the wafer are carried out while maintaining the hermetically-processed state of the wafer and the cleaning process to prevent natural oxidation of the wafer and contamination by dust.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those shown in FIG. 2 are designated by the same reference numerals.

The load lock chamber 2 is provided with a buffer chamber 10 capable of accommodating at least a plurality of wafers via a gate valve 9, and a transfer unit 12 having a wafer transfer machine 18 built in the buffer chamber 10 via a gate valve 11. Connect. A second cassette chamber 14 is connected to the transfer unit 12 via a gate valve 13, and a wafer cleaning unit 17 is connected via a gate valve 16. A cassette can be loaded into and unloaded from the second cassette chamber 14 via a gate valve 15.

Incidentally, the buffer chamber 10, the transfer unit 12, the second cassette chamber 14, and the wafer cleaning unit 17 are evacuated, or a gas supply / discharge device for supplying an inert gas such as nitrogen gas (see FIG. (Not shown).

The operation will be described below.

In the present embodiment, the gate valve 15 will be described for the case of cleaning before processing, the cassette 8 loaded with wafers is loaded into the second cassette chamber 14, and the gate valve 15 is opened. Block. The inside of the second cassette chamber 14 is replaced with nitrogen gas, and after the replacement is completed, the gate valve 1
3, the gate valve 16 is opened, and one wafer is taken out from the cassette 8 by the wafer transfer machine 18 and transferred to the wafer cleaning unit 17, and the gate valve 16
Is closed and the wafer is cleaned. When cleaning is completed,
The gate valves 16 and 11 are opened, and the wafer transfer machine 18 transfers the wafer from the wafer cleaning unit 17 to the buffer chamber 10.

The transfer from the second cassette chamber 14 to the wafer cleaning unit 17, the cleaning of the wafer in the wafer cleaning unit 17, and the transfer from the wafer cleaning unit 17 to the buffer chamber 10 are hermetically sealed. Are held sequentially while being held.

The transfer from the buffer chamber 10 to the vertical reaction chamber 1 is performed with the gate valve 9 open, and the wafer transfer machine 7 is transferred from the buffer chamber 10.
More wafers are held and transferred to the boat of the boat elevator 6.

When the boat is loaded with wafers, the gate valve 9 is closed, and the boat is loaded into the vertical reaction chamber 1 by the boat elevator 6. The CVD process is performed in the vertical reaction chamber 1, and after the process, the boat is placed in the vertical reaction chamber 1.
Then, the gate valve 3 is opened, and the wafer transfer device 7 transfers the wafers one by one to the cassette 8 that stands by in the cassette chamber 4.

When a wafer is loaded in the cassette 8, the gate valve 3 is closed, the gate valve 5 is opened, and the cassette 8 is taken out from the gate valve 5.

From the loading of the cassette 8 to its removal,
A series of processes and movements are performed in an airtight state.

[0022]

As described above, according to the present invention, the steps from the loading of the cassette to the cleaning process, the CVD process, and the unloading of the cassette are performed in an airtight state, so that the natural oxidation of the wafer is prevented and the dust is prevented. Therefore, it is possible to prevent the contamination due to, and it is possible to improve the product quality and the yield.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a conventional example.

[Explanation of symbols]

 1 Vertical reaction chamber 2 Load lock chamber 10 Buffer chamber 17 Wafer cleaning unit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuhiro Hirano 2-3-13 Toranomon, Minato-ku, Tokyo Kokusai Electric Co., Ltd. (72) Inventor Atsushi Koike 5-2-1, Kamimizuhoncho, Kodaira-shi, Tokyo Hitachi Ltd. Musashi Factory (72) Inventor Tomomasa Funahashi 5-20-1, Josuihonmachi, Kodaira-shi, Tokyo Incorporation Hitachi Ltd. Musashi Factory (72) Inventor Hirohiko Yamamoto Josui, Tokyo Honmachi 5-chome No. 20-1 Hitate Super LSI Engineering Co., Ltd.

Claims (1)

[Claims] 1. A vertical CVD, wherein a wafer cleaning unit is provided in a load lock chamber provided below the vertical reaction chamber with a buffer chamber provided in an airtight manner.
apparatus.