JPH03226579A - Atmospheric cvd device - Google Patents

Abstract

PURPOSE:To minimize the amt. of particles deposited on a wafer by providing a means for monitoring the suspended dust flowing out of a reaction chamber to detect a decrease in the gas exhausting capacity and removing the particles deposited in an exhaust pipe, etc. CONSTITUTION:The atmospheric CVD device is provided with a suction pipe 4 and a suspended dust detector 5 connected to the pipe. The suction pipe 4 is arranged close to the periphery of a reaction chamber 1. The number of suspended dust particles in the exhaust gas is counted by the detector 5. When the number of particles counted by the detector 5 exceeds a specified value, an alarm is issued.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an atmospheric pressure CVD apparatus.

[Conventional technology]

Conventionally, this type of atmospheric pressure CVD apparatus heats the wafer through a susceptor on which it is placed using an infrared lamp or high-frequency coil in order to suppress reactions in the gas phase.
This is an apparatus that introduces 4 (silane)-based gas to form a Si-based thin film. Although not shown in the drawings, normal pressure CVD equipment usually includes a reaction chamber for introducing gas to cause a chemical reaction, a supply pipe for introducing the reaction gas into the reaction chamber, and an exhaust pipe for exhausting the reacted gas. It had a tube, a tray and tray holder for placing wafers, and a gas exhaust pressure gauge for monitoring exhaust capacity.

[Problem to be solved by the invention]

The above-mentioned conventional atmospheric CVD apparatus has a gas exhaust pressure gauge as mentioned above, but this type of apparatus, which mainly uses 5iH4 (silane)'-based gas, produces a large amount of powder as a reaction product. S i 02 floating dust (hereinafter referred to as particles) is generated and adheres to the inner wall of the exhaust pipe. the result,
Even though the exhaust pressure gauge indicates a normal value, the cross-sectional area of the exhaust pipe decreases by 1, causing the exhaust flow rate to decrease. This licking increases the number of particles flowing out of the reaction chamber, and the particles adhere to the wafer exiting the reaction chamber.
There is a drawback that the yield is significantly reduced.

An object of the present invention is to provide an atmospheric pressure CVD apparatus that eliminates such drawbacks.

[Means to solve the problem]

The atmospheric pressure CVD apparatus of the present invention includes an intake pipe disposed close to the outer periphery of a reaction chamber, and a detector connected to the intake pipe and counting the number of floating dust in the intake exhaust gas. If the number of floating particles counted by this detector exceeds a specified value, an alarm will be issued.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 and FIG. 2 show an embodiment of the present invention using normal pressure CVD.
FIG. 3 is a partially cutaway front view and a side view of the device. This normal pressure CV
As shown in FIGS. 1 and 2, the device D includes an intake pipe 4 that is disposed close to the outside of the reaction chamber 1 and sucks up particles flowing out from the reaction chamber 1, and Detector 5 that detects and counts particles
In addition, a pump 11 is provided which is connected to the intake pipe 4 through piping and which exhausts outflowing gas.

Other than that, it is the same as before.

Next, the operation of this normal pressure CVD apparatus will be explained.

First, the wafer 2 is placed on the tray 10 supported by the tray holder 6, and the wafer 2 is placed in the reaction chamber 1. Next, a reaction gas is introduced into the reaction chamber 1 through the supply pipe 9. As a result, vapor phase growth starts on the surface of the wafer 9 due to a chemical reaction of the reaction gas. At this time, the reacted gas is exhausted through the exhaust pipe 3. Further, the reaction gas flowing out from the reaction chamber 1 is blown out from the duct 8 to dilute the reaction gas flowing out. On the other hand, the intake pipe is near the reaction chamber 1,
Since the detector 5 is installed at the side of the wafer entrance, particles in the inhaled atmosphere are counted by the detector 5. However, the exhaust pressure gauge 7 increases as the usage time progresses.

FIG. 3 is a block diagram for explaining the operation of a particle detection circuit including a detector. Next, the particles sucked in by the intake pipe 4 are counted by the detector 5.

This count signal is then sent to the controller 12, as shown by the dotted line in FIG. In this controller 12, the upper limit value of the particle count number is set in advance by the setting device 13, and the upper limit value signal is sent to the controller 5 as shown by the dotted line, and is compared with the particle count signal of zero order. When the number of particles exceeding this upper limit is counted as the exhaust pressure gauge increases, a signal is sent from the controller 12 to the alarm 14, which issues an alarm and cuts off the supply of the reactant gas. After stopping the device, remove the particles accumulated in the exhaust pipe 3,
Restart the device.

〔Effect of the invention〕

As explained above, the atmospheric pressure CVD apparatus of the present invention is equipped with a means for monitoring floating dust flowing out from the reaction chamber, so that particle generation due to a decrease in gas exhaust capacity can be immediately detected, and particle adhesion on wafers can be minimized. This has the effect of preventing a decrease in yield.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show an embodiment of the present invention using normal pressure CVD.
FIG. 3 is a partially cutaway front view and a partially cutaway side view of the device, and is a block diagram of a particle detection circuit including a detector. 1... Reaction chamber, 2... Wafer, 3... Exhaust pipe,
4... Intake pipe, 5... Detector, 6... Tray holder, 7... Exhaust pressure gauge, 8... Duct, 9... Supply pipe, 10... Tray 11... Pump, 12...
Controller, 13...setting device, 14...alarm device.

Claims (1)

[Claims] The reactor is equipped with an intake pipe placed close to the outside of the reaction chamber, and a detector connected to the intake pipe that counts the number of suspended dust in the exhaust gas being taken in. A normal pressure CVD device that is characterized by issuing an alarm when the number of suspended particles exceeds a specified value.