JPS5827637A - Gas supply circuit in gas pahse growing furnace - Google Patents

Abstract

PURPOSE:To obtain a homogeneous product, by bypassing a gas phase growing furnace from a position between a mass flow meter and a closing valve on a reactant gas supply line to supply the reactant gas in a stable set amount. CONSTITUTION:In a gas phase growing apparatus, a gas pahse growing furnace 1 is bypassed from a pipe line 3a between a mass flow meter 6 and a closing valve 7 on a reactant gas supply line 3 to be connected to an exhaust pipe line 4 and a bypass pipe line 10 having a closing valve 11 is arranged. In initiating the supply of the reactant gas to the furnace 1, the valve 11 is opened at first to flow out the reactant gas to the exhaust pipe line 4 and the throttling of the mass flow meter 6 is stabilized to a set valve and, thereafter, said gas is supplied to the furnace 1. By this method, production of hillock due to abrupt reaction can be prevented and a homogeneous product is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses CVD (Chemical Vapor
It is suitable for the gas supply circuit of the vapor phase growth furnace used in the deposition process.

As shown in Figure 1, the conventional vapor phase growth apparatus has carrier gas supply paths 2 and 8 such as N1 on the inlet side of the vapor phase growth furnace 10.
i) Reaction gas supply passages 3 such as 14 are arranged independently, and an exhaust passage 4 is arranged on the exit side of the vapor phase growth furnace 1, and furthermore, a tri m m is provided in the carrier gas supply v62.
Will In addition to intervening the control valve 5, the reaction gas supply path 3 is equipped with a mask low meter (a flow rate needle equipped with a current adjustment function) or a check valve 1f (hereinafter referred to as a mass flow meter) 6 and a closed valve downstream of the gas flow meter. A valve 7 is provided in each case, and a shutoff valve 8 is provided in the exhaust path 4, and a vacuum pump 9 is provided downstream thereof.

In this conventional vapor phase W, long device, when the shutoff valve 8 is opened with the vacuum pump 9 in operation, the flow rate control valve 5 is closed and Yayarya gas is supplied from the supply path 2 to the vapor phase growth reactor 1. be done. The supplied carrier gas is drawn from the vapor phase growth furnace 1 through the shutoff valve 8 by the vacuum pump 9 and discharged. When the carrier gas becomes a steady flow in this manner, the shutoff valve 1 is opened, the mass flow meter 6 and the shutoff valve T are worn out, and the reaction gas is supplied from the supply path 3 to the vapor phase growth reactor 1.

However, in the above-mentioned conventional vapor phase growth apparatus, when the carrier gas is being supplied to the vapor phase growth furnace 1 through the supply path 2 and the shutoff valve 7 is in a bad closing state, the mass flow is The meter 6 is fully open. Therefore, at the same time as the shut-off valve 7 is opened, the reaction gas instantaneously and electrically flows into the vapor phase A-long furnace 1 from the supply path 3, resulting in a rapid reaction and white powder, commonly known as hillocks, flying up. It adheres to wafers, etc., resulting in a decrease in IC yield.

The present invention provides a gas supply circuit for a vapor phase growth furnace that eliminates these drawbacks.

The present invention will be described below with reference to embodiments shown in the drawings. The gas supply circuit in the vapor phase growth reactor according to the invention is as follows:
A bypass pipe line 10 is connected from the pipe line 3a between the mass flow meter 6 on the reaction gas supply line 3 and the shutoff valve 7 to the exhaust line 4 by bypassing the vapor phase growth furnace 1 in the conventional vapor phase growth apparatus. In addition to piping, a shutoff valve 11 is interposed in the pipeline.

In the vapor phase growth apparatus configured in this way, when supplying the reaction gas to the vapor phase growth furnace 1, first the shutoff valve 11 is closed.
is opened, the reaction gas flows out into the exhaust pipe 4 via the bypass pipe 10, and the throttle of the mass flow meter 6 is thereby maintained at the set value VC.

Next, the shutoff valve 7 is opened, the reaction gas is supplied to the vapor phase growth reactor 1 via the feeder 1f63, and the shutoff valve 11 is then closed to shut off the bypass pipe 10. Therefore, the gas phase according to the present invention is In the gas supply circuit in the growth reactor, when supplying the reactant gas to the vapor phase growth reactor, it is possible to supply a stable set amount of reactant gas even in the initial stage, and as a result, it is possible to obtain uniform products. Monkey,

[Brief explanation of the drawing]

FIG. 1 is a piping diagram of a conventionally used vapor phase growth apparatus, and FIG. 2 is a piping diagram of a vapor phase growth apparatus of the present invention, VC9f. 1... Gas phase by, long furnace 2°゛° par carrier gas supply Ayu 3... Reaction gas supply path 4... Exhaust path 5... Flow rate control valve 6... Mass flow meter T, 8... Closing valve 9... Vacuum pump 10... Bypass pipe line 11... Closing valve. (7317) Representative Patent Attorney Noriyuki Chika (and 1 other person) Cha l @ Cha 2 Diagram

Claims (1)

[Claims] In a vapor phase growth reactor equipped with a carrier gas supply path and a reaction gas supply path independently, a pipe is branched between a mass flow meter in the reaction gas supply path and a shutoff valve located downstream thereof; The vapor phase growth reactor, which is a branched pipe, was bypassed and connected to the exhaust pipe, and a shutoff valve was interposed in the branched pipe! Gas supply circuit in a vapor phase growth reactor.