- 學位論文
矽晶圓輪磨技術效能提昇之應用分析
Application on Silicon Wafer Grinding Process Performance Enhancement
摘要
輪磨（Grinding）加工在半導體晶圓薄化封裝、晶圓製造、及晶圓再生產業有舉足輕重的地位。矽晶圓輪磨製程主要特色為可自動化、平坦度佳、表面粗糙度小、快速移除量、單位加工時間少、產出良率高。但是對於如何減少次表面破壞層（Sub-Surface Damage），降低殘留應力產生的翹曲（Warp）兩項技術瓶頸，是製程中必須有效控制及避免的重要項目。 本研究全程規劃三工作主軸，第一階段採用各式粒徑分佈暨不同燒結材料砂輪，使用G＆N奈米研磨機台進行加工驗證。其中主要利用矽晶圓單一磨粒切深延性加工理論並配合斜面觀察法，建立各式砂輪種類暨機台製程主要參數，與矽晶圓表面破壞層深度關係式。第二階段設計輪磨實際溫度量測裝置，結合第一階段收集之實驗數據，比較翹曲值與輪磨溫度之間的關係，再藉由控制機台參數及不同冷卻水添加物來改善晶片翹曲值，減少次表面層破壞層深度，節省砂輪削銳損失，以創造更大製程效益。第三階段使用單面蝕刻，藉由理論公式與實際量測晶片物性計算表面殘留應力，結合前兩階段完成之結果，找出有效提昇輪磨製程技術之應用。
並列摘要
Grinding has gained important status in the IC packaging , wafer manufacture and wafer reclaim industry. Grinding process could reach low TTV (Total Thickness Variation) , excellent surface roughness , rapid material removal rate , reduced cycle time and higher automation level. To avoid deep subsurface damage layer and reduce warpage caused by residual stress , assessment should be made prior to production run for the industry. This study will concentrate on grinding 8 inches silicon wafers , and three stages were planned. First , ductile regime grinding and cross-section method are introduced to investigate the subsurface damage layer and critical depth of cut , under the influence of grinding parameters and wheel types. Second , measurement of grinding temperature between grinding wheel and wafer surface device is made. With the relation between warp and grinding temperature established from first step , grinding parameters and suitable surfactant in the cooling water will drop the interface temperature and , hence , leading to lower warp . Third , front side etching and Stoney’s formula will be used to calculate the residual stress and attempt is made to forecast the subsurface damage layer depth.