以電化學法剝除氮化鉻薄膜之研究

Stripping of CrN Thin Films by Electrochemical Methods

本研究主要是以電化學法剝除鍍著於矽晶片上之氮化鉻薄膜，探討實驗過程中薄膜厚度變化、電解液濃度與電流密度對薄膜剝除時間之影響。首先以陰極電弧電漿沈積（Cathodic Arc Plasma Deposition）法，於矽晶片上鍍著氮化鉻薄膜，使用恆電位儀之定電流模式剝除氮化鉻薄膜，並以場發射掃描式電子顯微鏡觀察氮化鉻膜厚的變化情形。實驗過程中，KOH電解液由無色透明轉為淡黃色，而氮化鉻膜厚度隨著電流密度及時間的增加而逐漸變小。完全剝除單位體積的氮化鉻薄膜所需之時間與電流密度成反比，而KOH電解液濃度則與剝除所需時間無明顯之關係。最後以數學模式分析在不同電流密度與KOH濃度下，剝除厚度及剝除時間之關係。

In this study the chromium nitride (CrN) films deposited on (100) silicon wafer by using cathodic arc plasma technique were stripped in alkaline electrolyte via electrochemical method. Various current densities and electrolyte concentrations were used to investigate the influence on stripping time and changes of the film thickness. The changes of the films thickness during stripping process were investigated by field-emission scanning microscopy. The thickness of the remained films decreased as the current density increased. Times required to complete remove the nitride films were inverse proportional to the current density, but irrespective of the concentration of electrolyte. The relationship between the thickness and stripping time at various current densities and KOH concentrations was analyzed using a mathematical model.