應用實驗設計改善閘極製程之晶圓缺陷數

Abstract

本文探討原本為製造標準型之DRAM的半導體公司，為避免供需失衡問題，決定轉型代工製造服務，該公司於導入邏輯晶圓代工產品量產初期，在閘極乾蝕刻製程，發現有particle隨機附著於晶圓表面上，且無法於下一站清洗製程將particle去除，造成晶圓閘極缺陷，導致1.2%晶圓報廢率，且因particle過高，須停機執行設備保養，造成機台保養費用上升。為滿足客戶所期望的高品質與低價格的代工產品，必須著力於降低閘極晶圓缺陷數，以提升線上良率，降低機台保養成本。本研究透過實驗設計法，找出閘極乾蝕刻製程造成晶圓缺陷的主要因子、因子間交互作用及最佳化參數組合，有效改善晶圓缺陷數，因而降低晶圓報廢率及額外產生的機台保養費用。

This article discusses that the semiconductor company of commodity DRAM oriented, in order to avoid disequilibrium of supply and demand, decided to transition to wafer foundry manufacturing services. The company found random particle attached to the surface of the wafer at the poly gate of dry etching process since the logic product was introduced into mass production. The particle can not be removed next cleaning process caused wafer defects and scrap ratio was 1.2%. Since the particle was too high, the equipment must be shut down to perform preventive maintenance that resulted in increasing the cost of maintenance. To fulfill customer expectations of high quality and low price of foundry products, it is necessary that the company need to be focused on reducing wafer defects of the poly gate of etch process to improve inline yield and reduce machine maintenance cost. Using experiment of design to identify significant factors and find out the interaction that caused wafer defect, and obtain the optimum parameter combination at the poly gate of etch process to reduce defect counts. Finally improve line yield and reduce extra maintenance costs from equipment.