光學掃瞄矽晶片背面之積體電路成像

Abstract

本論文是以光學掃瞄系統為基礎，針對矽晶片內部的結構成像設計出有效方便的架構。就設計考量上了除了要求解析度能提升外，在進行晶片反面掃瞄時，更需克服高折射係數矽基板的存在對成像品質的影響。文中吾人會先利用光學模擬軟體，輔助設計光路系統，並分析各個元件對掃瞄與傳統顯微鏡成像的影響。最後再由實驗的結果與模擬數據相輔驗證，並引入數位影像處理方式進一步提升影像品質。在實驗過程裡，系統對於不同晶片的薄厚與材料會有不同的解析度及對比，目前已能得到5□m清晰的結構，其解析度約略小於1□m。 本論文的目的在於透過掃瞄系統，冀求利用矽的能階吸收探測製程缺陷。而最後實驗的結果我們能清楚地比較，通以電流升溫前後影像有明顯的不同，這樣的結果也更進一步驗證熱影像檢測應用在半導體檢測的可行性。

The purpose of this thesis is based on optical scanning systems to probe the inner structures of silicon IC chips by compendious and valid methods. Except for high resolving power, the design introduces more consideration to the present of silicon substrate, whose high refractive index influences the imaging process results strongly. In our experimental steps, we first make use of simulation software to help designing the optical route and introduce each component involved. Next, we compare it with experimental results and try to improve the image qualities by digital image processing methods. Up to now, we have obtained clear pictures for a structure under 5□m, and based on the image resolution is estimated around 1□m。

In combination this scanning system, we study the thermal image originating from the bandgap absorption of silicon in order to find out the defects in the IC circuits. Experimentally, we scan a 0.09□m process chip and observe apparent differences before and after a voltage being applied to this chip. It is prominent that we can apply this technique for inspection to silicon IC chip examination by the thermal imaging methods.