Gas mixing controller of semiconductor device

Abstract

The invention relates to a gas mixing controller of a semiconductor device. The gas mixing controller adopts the following technical schemes that the gas mixing controller comprises an input part, a control processing part, an output part, RS485 communication ports and a power supply; the input part comprises an analogue signal collecting module, an oxyhydrogen ratio input module and an SIH4 pressure input module; the output part comprises an analogue channel output module, a control channel output module, an oxyhydrogen ratio protection output module and an SIH4 over-pressure output module; one RS485 communication port is connected with a digital mass flow meter; the other RS485 communication port is connected with an upper computer; the power supply adopts an isolation DC-DC (direct current to direct current) module, and the power supply is converted through the isolation DC-DC module into power supplies required for five loops, namely the gas mass flow meter, the analogue channel chip, a single chip system, a main communication port and a slave communication port. The controller disclosed by the invention can monitor gas flow of different mass flow meters according to control rules and programs which are transmitted by the upper computer for the gases, carries out interlock and protection at the same time, can be suitable for the gas analogue mass flow meter or the digital mass flow meter, can be connected with eight mass flow meters, is especially suitable for the device with gas control of the semiconductor, and is high in intelligence, strong in function, low in cost, high in accuracy, safe and reliable.

Description

technical field [0001] The invention belongs to the field of controllers, in particular to a gas mixing controller. Background technique [0002] In the manufacture of semiconductor devices and integrated circuits, certain or certain impurities are doped into semiconductor materials to make the materials have the required conductivity type and certain resistivity, which are used to manufacture PN junctions, resistors, buried layers, etc. The gaseous doping sources used in the doping process are called doping gases. Usually, the dopant source and the carrier gas are mixed in the source cabinet. After the mixing, the gas flow continuously flows into the diffusion furnace and surrounds the wafer. Compound dopants are deposited on the surface of the wafer, and then react with silicon to form doped metals. This requires a manager that centrally controls the flow of several gases. According to different semiconductor or process requirements, the gas types, quantities and mixing ...

AI Technical Summary

Problems solved by technology

However, there are problems that are difficult to solve when using PLC to realize communication: 1. PLC generally has an RS232 port connected to the upper computer and an RS485 interface connected to the lower computer. The communication protocol is different from that of some mass flowmeters. For example, the data bit in the communication protocol of the Japanese physical and chemical FB400 temperature instrument is 8, while the communication protocol data bit of the SEC mass flowmeter of Japan’s HORIBA is 7. If you use this RS485 port, In each communication, different protocols are initialized for different instruments, which is easy to cause data confusion, long communication time, and reduced efficiency

However, the disadvantage of this solution is that once the control computer system crashes or other failures, the monitoring of the gas will fail, and the experiment will suffer losses.

Using this scheme to build a control system is not a standardized fieldbus control system, nor a standardized supervisory control system, so that the safety and reliability of the system cannot be guaranteed.

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