矽晶絕緣層破壞韌性的聲彈研究

Abstract

矽晶絕緣普遍應用於CMOS中，以防止閉鎖及電性隔絕。晶圓鍵結之矽晶絕緣具有優異的絕緣性質，可做為CMOS之基材。矽晶絕緣層的破壞韌性對於晶圓接受化學反應機械研磨程序有重要的影響。本研究應用聲彈理論分析晶圓鍵結之三明治單晶矽平板脫層裂紋的ModeII及Mode III混合模式破壞韌性，藉散射係數、裂縫尖端張口位移及入射波應力場之間的定量關係，建立一套量測三明治異向性平板脫層破壞韌性的超音波非破壞檢測方法。

The thesis establishes a quantitative method based on acousto-elasticity to determine the fracture toughness of silicon-on-insulators (SOI). SOI technology is being used increasingly in complimentary metal-oxide-semiconductor (CMOS) devices. The SOI utilizing boding of oxidized silicon wafers features very high quality insulation properties. The bonding process accompanied by subsequent removal of most of one of the wafers by chemical-mechanical-polishing (CMP) means creates a generic SOI wafer. The proposed method evaluates the quasi-static surface energy of the bond by the work done by shear traction of the incident flexural waves on the sliding crack opening displacements. The work is identical to the measured or calculated scattering coefficient. The surface energy is also determined by static analysis of finite element for the delamination flaws embedded in the brittle silicon dioxide substrates.