熱應力誘發藍寶石基底上單晶矽薄膜轉移之研究

Study of thermal stress-induced layer transfer from single-crystal silicon thin film on sapphire substrate

許睿穎(Jui-Ying Hsu)

指導教授 ： 李天錫

國立中央大學/工學院/機械工程學系/碩士(2011年)

摘要

藍寶石基底上矽（Silicon on Sapphire；SOS）有良好的藍寶石來作為矽磊晶層之基底，能磊晶出良好的矽晶品質，故能應用於光電、通訊、半導體、太陽能面板等薄膜上。現今最常見的矽薄膜轉移技術為Smart-cut®，是利用高劑量高能量的氫離子佈植在欲轉移深度之矽晶層中，再以高溫退火使得氫離子濃度高峰之位置產生剝離，達成矽晶薄膜轉移的目的，但Smart-cut®之技術設備高價昂貴；近四年來比利時的校際微電子研究中心 (Interuniversity Microelectronics Centre；IMEC)發展出SLiM-Cut技術（Stress induced Lift-off Method），利用矽晶材料特性的熔點高與熱膨脹係數小，金屬材料熔點低與熱膨脹係數高的原理進行薄膜轉移。

　　本研究想法即是利用兩材料熱膨脹係數不同的原理進行研究：先將SOS表面經過化學溶液處理浸泡後，將金屬鋁材加熱使之鍵合於矽材上，令材料冷卻時因膨脹係數不同產生熱應力，致使矽材與藍寶石剝離，使矽晶薄膜轉移到金屬鋁材上，並使用OM、SEM、EDS與SIMS等儀器檢測並探討其結構，轉移後之矽晶薄膜可以應用於太陽能面板等相關產業上，而藍寶石又可以再次磊晶利用。

關鍵字

藍寶石上矽 ； 熱應力 ； 熱應力誘導轉移法 ； 智切法 ； 含氫離子化學溶液 ； 共晶鍵合 ； 藍寶石 ； 薄膜轉移 ； 晶圓鍵合 ； 薄膜熱應力 ； 鋁-矽共晶

並列摘要

Silicon on sapphire can be applied to Optical Engineering, communications, semiconductor, and thin film solar cell, because good sapphire for the substrate can epitaxial high quality silicon layer. The most well-known silicon film layer transfer technique is the Smart-cut®. It works by implanting high dose hydrogen ion in the desired depth of the silicon layer, and annealed at high temperature for separation in the location of the peak of the hydrogen. Then the silicon film transfers to another wafer. The past four years in Belgium, Interuniversity Microelectronics Centre (IMEC) developed a new technique called Slim-Cut. Silicon is high melting point and small thermal expansion coefficient. Metal is low melting point and large thermal expansion coefficient. These are the principles for Slim-Cut research layer transfer.

　　This study uses this principle that two kinds of materials’ thermal expansion coefficient are different. Silicon on sapphire has been soaked in chemical solution. Metal aluminum can bond on the silicon material by heating. When cooling, they produce thermal stress by two different expansion coefficients. Then silicon layer on sapphire transfers to the metal aluminum. This study uses OM, SEM, EDS, and SIMS to test the structures, and discuss these results. We wish the study’s material silicon thin film solar panels can be applied to related industries. The sapphire without silicon is recycled and epitaxial for using again.

並列關鍵字

thin film thermal stress ； wafer bonding ； sapphire ； silicon on sapphire ； layer transfer ； eutectic bonding ； thermal stress ； Smart-Cut ； SLiM-Cut ； chemical solution containing hydrogen ions ； the Al - Si eutectic

參考文獻

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