基于离子切割技术制备的绝缘体上锗(GeOI)材料缺陷的去除方法研究

项目名称： 基于离子切割技术制备的绝缘体上锗(GeOI)材料缺陷的去除方法研究

项目编号： No.61274105

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 张轩雄

作者单位： 上海理工大学

项目金额： 92万元

中文摘要： 锗的高载流子迁移率特性使其成为将来CMOS晶体管沟道的理想材料。利用类似SOI结构的GeOI（Germanium-on-insulator）结构的氧化物埋层抑制其窄禁带导致的漏电成为业界追逐的目标。目前制作晶圆级GeOI材料最大的问题是锗层高缺陷密度。离子切割技术是制备GeOI的重要方法之一，但其中Ge/SiO2低温均匀键合问题导致高密度缺陷（即局部Ge层转移失效，在Ge层留下密集针孔）阻碍GeOI材料的应用。本研究主要创新是利用对低温键合界面气泡更加敏感的Ge/Si晶圆直接键合，探索去除界面可见气泡的锗表面条件，用此条件进行Ge/SiO2低温键合以去除界面可见气泡，又对键合后的锗单面减薄至10μm以下使可能的"隐形"气泡显露（锗薄层脱落），再调整键合工艺，使Ge/SiO2均匀键合。最后结合H离子注入锗后形成platelets（Ge-H小板块）的退火起泡动力学控制，实现无缺陷GeOI制作。

中文关键词： 离子切割锗层转移；低温键合技术；智能剥离技术；GeOI晶圆；半导体晶圆的氢注入

英文摘要： Ge with higher carrier mobility of electrons and holes can be used as the transistor channel. Ge has to integrate with silicon in order to sufficiently make use of the platform from the perfect silicon CMOS technology. Ge-on-insulator (GeOI), such as silicon-on-insulator (SOI) structure, should be employed to suppress the current leakage caused by narrow bandgap (0.66eV) as Ge is used as a transistor channel material. The technology in combination of wafer bonding and layer transfer (called as ion-cut technology) is important one of manufacturing approaches to achieve GeOI. The high defect (pin hole) density generated by some local unavailable layer transfer is blocking GeOI application up to now. However, the wafer bonding of Ge to silicon dioxide has to be carried out under a low temperature for avoiding the bonded pair crack thanks to the difference of thermal expansion coefficient between both materials and the demand of ion-cut kinetics. The annoying visible and invisible bubbles at the bonding interface are often caused during low temperature wafer bonding. In this proposal, the direct wafer bonding of Ge to silicon will be first employed to explore the Ge surface condition of bubble-free wafer bonding because Ge/Si wafer bonding is usually more sensitive to the interface bubbles than that of Ge to silicon

英文关键词： Germanium layer transfer；low temperature wafer bonding；Smart-cut；GeOI wafer；H-implanted semiconductor wafer