聚亞醯胺的導孔成型之研究

Abstract

本實驗的目的在製作MCM-D型構裝多層連線基板之導孔。探討濕式化學蝕刻與RIE蝕刻技術應用於Du Pont 公司的PI-2555聚亞醯胺志孔形成的特性，以瞭解各蝕刻機制的效應。 實驗結果顯示，濕式蝕刻的蝕刻速率極快(0.17∼1.08um/sec)，其蝕刻速率與PI亞醯胺化程度有關。由於牽涉化學反應，所以為等向性蝕刻（等向性＝0.3∼0.4），並有嚴重的負載效應(Load Effect)。改變軟烤條件，對等向性沒有極大的影響。 RIE可藉著調整製程參數，來控制非等向性。蝕刻非等向性程度0.7∼0.92，導孔傾斜角67°∼85°本實驗的變數為氣體流量、系統壓力、功率及氣體組成。蝕刻的氣體為氧氣、SF6及CHF3。觀察不同參數對值流偏壓、蝕刻速率及導孔側面輪廓的影響。直流偏壓不是製程參數，但它代表物理蝕刻效應的影響。PIE與溼式蝕刻比較，共蝕刻速率極慢(0.02∼0.67um/mi)，但負載效應較輕微。

In this work we studied the via formation in Du Pont PI-2555 Polyimide by employing the wet chemical etching and reactive ion etching (RIE) processes. Experimental results indicated that wet etching was a very fast (etching rate≡0.17∼1.08um/sec), simple, and low-cost technique. However, it exhibited serious via undercut and load effect due to its isotropic etching nature (the degree of isotropy≡0.3∼0.4). RIE si a pleasma-based dry etching technique characterized by a combination of physical sputtering and chuemical etching. RIE offfered good control of etching profile when processiong variables were carefully selected. The degree of anisotropy was 0.7∼0.92 varied with etching conditions. The disadvantages of RIE would be its complexity that an optimum etching conditions was very difficult to establish. Comparing with wet etching, RIE process had a very low etching rate (0.02∼0.67um/min), but the load effect was less serious.