利用實驗設計法改善晶圓測試誤宰問題-以A晶圓測試廠為例

Abstract

近年來由於半導體製程技術不斷的提升，積體電路朝向體積小、密度高，迫使半導體產業中的晶圓測試變的格外重要，在晶圓測試中，測試程式、測試機台、探針卡、測試溫度以及各種測試相關參數都可能直接影響測試的品質。當發生晶圓測試誤宰(Overkill)時，必須優先解決誤宰原因，然後進行晶圓重測，然而重測對於晶圓測試廠而言，將造成時間的浪費、生產週期及成本的增加，影響交期與產能利用率。為協助A公司改善晶圓測試誤宰問題，本研究透過實驗設計(Design of experiment,DOE)，於晶圓測試參數中找出造成測試誤宰的顯著因子，藉由實驗結果，透過變異數分析(Analysis of variance,ANOVA)了解各顯著因子的影響後發現藉由製程參數中的針測行程與清針次數的設定，能有效降低測試誤宰問題的發生。此研究成果除了改善晶圓測試誤宰問題以及降低龐大的重測成本外，也提供給晶圓測試廠及業界在追求提升品質與降低成本的改善策略作為參考。

The development of IC（Integrated Circuits）faces small volume and high density as a result of semiconductor process technology continuously improves in recent years,wafer testing process has become especially importment in the semiconductor industry.In wafer test process, test program,tester,probe card, temperature and various test conditions may directly influence test quality.We have to solve the root cause directly and then re-testing wafer when overkill occurrence.However,wafer re-testing will bring about time consumption、long cycle time、cost enhancement、delivery and capacity utilization in wafer testing factory. This research tries to use Design of Experiment(DOE) to explore the major root cause of overkill problems in wafer testing process for A company. Analysis of variance(ANOVA) was applied to analyze factors effect via factor experiment. This study found that the overdrive of probing and clean wafer setting are the key factors to improve the overkill issue of wafer testing.The achievements improved overkill issues and reduced mass re-testing cost of wafer testing process for A company.This study may also provide as a practical reference to improve the wafer testing quality and cost reduction decision-making reference for wafer testing factory and semiconductor industry.