智能剥离制备GOI材料  

Fabrication of Germanium-on-Insulator by Smart-Cut^(TM) technology

作　　者：赖淑妹 毛丹枫 陈松岩[2] 李成[2] 黄巍[2] 汤丁亮[3] 

机构地区：[1]闽南理工学院,泉州362700 [2]厦门大学物理系,厦门361005 [3]厦门大学化学化工学院,厦门361005

出　　处：《南京大学学报（自然科学版）》2017年第3期441-449,共9页Journal of Nanjing University（Natural Science）

基　　金：国家重点自然科学基金(61534005);国家自然科学基金(61474081);国家重点基础研究计划(973计划)(2013CB632103)

摘　　要：绝缘体上锗(Germanium-on-Insulator,GOI)结合了Ge材料及SOI(Silicon-on-Insulator)结构的优点,是一种极具吸引力的Si基新型材料.GOI材料不仅具有高的电子和空穴迁移率,同时其独特的全介质隔离结构可以避免短沟道效应,降低寄生电容和结漏电流.首先研究不同表面处理方法对体Ge与SiO2/Si晶片键合强度的影响,实验结果显示采用N2等离子体活化处理结合氨水溶液(NH4OH∶H2O=1∶10)亲水性处理,所得到的体Ge与SiO2/Si晶片的键合效果较好,其键合强度>3.8 MPa.利用智能剥离技术(Smart-Cut TM)制备了绝缘体上锗材料.SEM测试显示GOI材料键合质量良好,界面清晰平整,并且Ge层大部分面积无空洞.实验分析得到GOI材料的压应力及XRD(004)摇摆曲线中Ge峰的不对称是由GOI表面的注氢损伤层引起的.真空500℃退火30min对于注入损伤层的应力具有释放作用,但无法修复注入损伤.用溶液(NH4OH∶H2O2∶H2O=1∶1∶10)腐蚀去除注入损伤层后,应力层被去除,并且获得Ge峰半高宽仅为70.4arc sec的GOI材料.Germanium-on-Insulator（GOD, which combines the merits of Ge and SOI,is gaining interest as a newly emerged Si-based material. GOI substrate not only has high carrier mobility, but also can avoid the short channel effect, reduce the parasitic capacitance and the leakage current. Several methods to fabricate GOI substrate are available,such as Ge condensation,liquid-phase epitaxial（LPE）growth and Smart-CutTM technology. Among them, Smart-CutTM technology is more suitable for device fabrication due to its low defect density. However,wafer direct bonding,which requires gaining a high bonding strength at low annealing temperature,is the key step and nodus on the Smart-CutTM technology. Hence, before bonding, a strict surface treatment intending to improve the bonding strength is required. In this article, the effects of ammonium hydroxide（NH4 OH：H2O= 1：10）treatment, O2 plasma treatment and N2 plasma treatment on the wafer bonding strength were studied. Results showed that combining N2 plasma treatment to activate Ge and SiO2/Si wafers surface with ammonium hydroxide（NH4 OH：H2O = 1：10）to improve the Ge surface hydrophilicity, a good bonding quality of Ge/SiO2/Si structure with a strong bonding strength（〉3.8 MPa）was received. The GOI substrate with a Ge layer about 1μm was fabricated by Smart-CutTM technology. A smooth and distinct Ge/SiO2 interface was revealed by SEM measurement,and no void was formed in a majority of Ge surface as well. A damaged layer around the hydrogen ion range was generated during hydrogen implantation,and it was left on the GOI surface. Experiments show that the compressive stress of the GOI substrate, and the asymmetric of Ge peak in XRD（004）rocking curve were induced by the damaged layer. It was found that post-annealing in vacuum at 500℃ for 30 min could release the stress of damaged layer, but unable to restore damaged layer. Once the damaged layer was corroded by NH4 OH ： H2O2 ： H2O = 1 ： 1 ： 10 solution, the stress was removed as well. As shown b

关 键 词：晶片键合 智能剥离 绝缘体上锗(GOI) 退火 腐蚀 半高宽 

分 类 号：TN304.055[电子电信—物理电子学]