LPCVD furnace pipe and main valve interlocking device circuit thereof

Abstract

The invention provides an LPCVD furnace pipe and a main valve interlocking device circuit thereof. The input end of the circuit is connected with a vacuum detector; the output of the circuit is corresponding to a technology termination part of the furnace pipe; a dual power input is adopted by the circuit; the circuit comprises a first resistor, a second resistor, a potentiometer, a comparator, a third resistor, an audion, a relay, a fourth resistor and a state display element, wherein one end of the first resistor is used for receiving vacuum detecting signals; the second resistor and the potentiometer are connected in series and then are connected between a positive power supply end and a ground end and operation voltages of the comparator corresponding to set values of the furnace pre-vacuum are provided; the positive input end of the comparator is connected between the second resistor and the potentiometer and the negative input end of the comparator is connected with the other end of the first resistor; the comparator is further connected with the positive power supply end and the negative power supply end respectively; one end of the third resistor is connected with the output end of the comparator; the base electrode of the audion is connected with the other end of the third resistor and the emitter is grounding; one end of the relay is connected with the collector electrode of the audion and the other end of the delay is connected with the positive power supply end; one end of the fourth resistor is connected with the collector electrode of the audion; one end of the state display element is connected with the other end of the fourth resistor and the other end of the state display element is connected with the positive power supply end.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing equipment, in particular, the invention relates to an LPCVD furnace tube and a main valve interlocking device circuit thereof. Background technique [0002] LPCVD (low pressure chemical vapor deposition) furnace tube will first open the small valve (secondary valve) to establish a pre-vacuum after entering the furnace, and then open the large valve (main valve) to establish a deposition vacuum after 5 minutes. In this process, the pre-vacuum may not be established due to various failures of the furnace tube equipment, and the main valve will be opened directly to establish the deposition vacuum after 5 minutes, which will cause too much turbulence in the furnace tube and cause crystallization. There are countless particles on the disc. [0003] One of the reasons for the above problems is that the pre-vacuum cannot be established due to deposits in the inlet hole of the auxili...

AI Technical Summary

Problems solved by technology

In this process, the pre-vacuum may not be established due to various failures of the furnace tube equipment, and the main valve will be opened directly to establish the deposition vacuum after 5 minutes, which will cause too much turbulence in the furnace tube and cause crystallization. Numerous particles on the disc

[0003] One of the reasons for the above problems is that the pre-vacuum cannot be established due to deposits in the inlet hole of the auxiliary valve in the main valve. However, in the prior art, the LPCVD furnace tube cannot be established when the pre-vacuum cannot be established or the desired value cannot be obtained. Timely termination of the process

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