Measurement Technology of Dry Etching Chlorinated Byproducts and Improvement Strategy in Thin Film Transistor Liquid Crystal Display Production

Abstract

PP-29-018 Background/Aims: The advanced TFT-LCD processes, dry etching of thin film layers is increasingly preferred instead of conventional wet etching processes for new process. The previous studies are focus on greenhouse gases removal efficiency by scrubber, and indicate potential fluorinated or chlorinated compounds of the material being etched. The environment, safety, and health difficult challenges are lack of information on how the chemicals and materials are used and what process byproducts are formed, additional needs are characterizing and controlling plasma etches gas emissions and byproducts. Methods: The thermal processing unit consists of an oxide combustion chamber, a wet scrubber, a vacuum pump, and temperature/pressure control system, integrated in an enclosed unit. Determination of dry etching gas and byproducts using an online extractive Fourier transform infrared spectroscopy and canister sampling/gas chromatography-mass spectrometry method. A portable photo ionization detector used to detect total volatile organic compounds after scrubber. We found sulfur hexafluoride etching gas and 3 byproducts, including sulfur dioxide, ethylene, and hydrogen chloride by FTIR. There were 14 unknown and 6 byproducts before TPU, and 13 byproducts after TPU by Gas Chromatograph-Mass Spectrometer. Results: We found that the scrubber has high destruction removal efficiency for dry etching unknown byproducts at 1000°C. The temperature of partial combustion reactor processing equipment less than 750°C, toxic chlorinated byproducts would be generated after TPU. In this study, we found 34 chlorinated byproducts at abnormal local scrubber. The portable photoionization detector screen method is able to find abnormal scrubber, the concentration of total volatile organic compounds more than normal scrubber after TPU. Conclusion: We have established the dry etching chlorinated byproducts measurement technology and improvement strategy for local scrubber. When the local scrubber was not well maintained, toxic chlorinated byproducts would be generated. The screen method is able to screen out and modify the abnormal local scrubber for improvement.