積體電路閘極清洗製程參數最佳化 – 以T公司為例

Abstract

科技日新月異，消費者所使用的電子產品朝著輕、薄、短、小的外型邁進，相對的在這一些電子產品裡面所用到的晶片也是邁向微小化的方向；這也就是半導體晶圓代工產業所製造的晶片尺寸愈來愈小的原因。而在過去舊有的八吋晶圓廠面臨著如何利用舊有的設備來製造出微小化線寬晶片的課題。本研究的個案為一半導體晶圓代工公司的八吋晶圓廠，在引進新進的閘極製程時，卻在閘極多晶矽蝕刻後發現造成無數的缺陷，產品更在後段的封測廠發現良率降低6%左右。在經過分析及排除多項可能造成異常的原因後，該晶圓廠認為問題可能肇因於濕式清洗設備。為協助T公司晶圓廠釐清造成異常的原因，本研究利用實驗設計手法，分析清洗機台造成晶片缺陷的可能原因；最後找出最佳化的製程參數為增加最終純水洗淨時間，並成功的改善T公司產品良率，增加產品競爭力。

As the science technology changing rapidly, the electronic products which consumers used have become light, thin, short, and small, and the chips inside are growing miniaturized. This is the reason why the chips’ size manufactured by the semiconductor manufacturing foundry industry getting smaller and smaller. Now, the original 8 inch wafer factories face with the challenge that how to use old equipment to produce smaller chips with critical dimension. This case studies an 8 inch wafer manufacturing factory found several defect cases in Poly etching stage as introducing new technology of the Gate OX process, and the product would reduces 6% yield in the packaging and testing plant. After analysis and excluding a number of reasons which may cause abnormal, the FAB thinks that the problem might result from wet cleaning equipment. To help clarify the cause of abnormal for T company, this study uses DOE to analyze main reasons of defects caused by cleaning wafer machine. to offer the improvement program, and to find the optimal process parameters.