Cu gettering to nanovoids in SOI materials  

作　　者：张苗 吴雁军 刘卫丽 安正华 林成鲁 朱剑豪 

机构地区：[1]State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and information Technology, Chinese Academy of Sciences, Shanghai 200050, China [2]Department of Physics and Materials, City University of Hong Kong, China Correspondence should be addressed to Zhang Miao

出　　处：《Science China(Technological Sciences)》2003年第1期60-70,共11页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 69906005) and Shanghai Youth Foundation under grant No. 01QMH1403. The authors would like to thank Prof. P. F. P. Fichtner at Universidade do Rio Grande do Sul Brazil for the TEM an

摘　　要：In this paper, the gettering of Cu impurities in silicon-on-insulator (SOI)materials is studied. Nanovoids are formed in the substrate of SOI beneath the buried oxide (BOX) byroom temperature H^+ (3.5 x 10^(16) / cm^2) or He^+ (9 x 10^(16) / cm^2) implantation andsubsequent annealing at 700℃. The gettering of different doses of Cu (5 x10^(13)/cm^2, 5x10^(14)/cm^2, 5 x 10^(15)/cm^2), which are introduced in the top Si layer by ion implantation, to thenanovoids are investigated by cross-section transmission electron microscopy (XTEM) and secondaryion mass spectroscopy (SIMS). The results demonstrate that Cu impurities in the top Si layer candiffuse through the buried oxide (BOX) layer of SIMOX and Smart-Cut SOI at temperature above 700℃and be trapped by the nanovoids. Some of Cu impurities can be captured by the intrinsic defects atthe BOX interface of SIMOX, but will be released out at high temperatures. The gettering effect ofSIMOX intrinsic defects at BOX is much rower than that of the nanovoids. No Cu impurities aretrapped at the perfect BOX interfaces of Smart-Cut SOI. After 1000℃ annealing, high dose of Cu (3.6x 10^(15)/cm^2) was gettered by the nanovoids. The Cu gettering efficiency to the nanovoidsincreased with the decreasing of Cu doses. When the Cu doses in the top Si layer were lower than 4 x10^(15) /cm^2, nanovoids could getter more than 90% of the Cu impurities and reduce the Cuconcentration in the top Si layer to less than 4%. The results indicate that nanovoids gettering isa promising method for removing the impurities in SOI materials.

关 键 词：SOI  gettering  ION implantation  nanovoids. 

分 类 号：TN304.055[电子电信—物理电子学]