End point detection device and end point detection method

Abstract

The invention discloses an end point detection device used for detecting an end point of a xenon difluoride gas phase etching process. The end point detection device comprises a process cavity, a gas concentration detection device, an end point control device and a gas intake control device, wherein the process cavity is provided with a gas inlet and a gas outlet; the gas concentration detection device is provided at the gas outlet of the process cavity and detects the concentration of a xenon difluoride gas discharged from the process cavity; the end point control device is connected with the gas concentration detection device, calculates the concentration of the discharged xenon difluoride gas according to a detection result of the gas concentration detection device, and compares the concentration with a preset concentration value, and the end point control device generates and sends a control signal if the concentration of the discharged xenon difluoride gas is equal to or greater than the preset concentration value; and the gas intake control device is connected with the gas inlet of the process cavity, constant quantity of the xenon difluoride gas is filled in the process cavity through the gas inlet of the process cavity, and the gas intake device stops filling the xenon difluoride gas into the process cavity after receiving the control signal sent by the end point control device. The invention further discloses an end point detection method.

Description

technical field [0001] The invention relates to the technical field of gas phase etching, in particular to an endpoint detection device and an endpoint detection method of a xenon difluoride gas phase etching process. Background technique [0002] Xenon difluoride (XeF 2 ) Because of its high selectivity to common materials used in semiconductors, xenon difluoride gas is often used to etch excess metal when making interconnect structures for semiconductor devices. In order to improve the uniformity of xenon difluoride gas phase etching, it is very necessary to detect the end point of the etching process during the etching process. [0003] At present, the commonly used detection method for the end point of the xenon difluoride gas phase etching process is to control the end point by calculating the time when the xenon difluoride gas is introduced into the process chamber. However, considering the fluctuation of process parameters during the process, such as changes in flow...

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Problems solved by technology

However, considering the fluctuation of process parameters during the process, such as changes in flow rate, pressure and temperature, etc., it will affect the etching rate of xenon difluoride gas on the etched object. In this case, the process time set in advance It is inaccurate to control the end point, which will cause the uniformity of etching to fail to meet the process requirements or cause serious over-etching, which will affect the performance of semiconductor devices and reduce the yield of semiconductor devices

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