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采用纳米孔吸杂方法对新型硅基材料SOI(silicon-on-insulator)中的Cu杂质进行了吸除研究.室温下,将3.5×1016cm-2的H+或9×1016cm-2的He+注入到SOI氧化埋层下面的硅衬底内,700℃退火形成纳米孔,研究纳米孔对SOI顶层硅中不同剂量Cu杂质(5×1013,5×1014,5×1015cm-2)的吸除.剖面透射电子显微镜(XTEM)与二次离子质谱(SIMS)分析表明,700℃以上,Cu杂质可以穿过SIMOX和Smart—Cut材料不同的氧化埋层到达硅衬底,并被纳米孔吸附.SIMOX氧化埋层界面的本征缺陷对Cu杂质具有一定的吸附作用,但吸杂效果远远低于纳米孔吸杂,且高温下会将杂质释放出来.Smart—cut SOI的氧化埋层界面完整,不具备吸杂作用.1000℃退火后,纳米孔可吸附高达3.5×1015cm-2以上的Cu杂质,纳米孔吸杂效率随Cu注入剂量的降低而升高.当顶层硅中Cu剂量低于5×1014 cm-2时,纳米孔吸杂效率达到90%以上,并将顶层硅中Cu杂质浓度降低到原来的4％以下.纳米孔吸杂是一条解决SOI杂质去除难题的有效途径.
Using nanopore gettering methods novel silicon-based material SOI (silicon-on-insulator) in Cu impurities the gettering study. At room temperature, the H + or He 3.5 × 1016cm-2 of 9 × 1016cm-2 + implantation and to the SOI buried oxide below the silicon substrate, 700 ℃ annealed to form nanopores, nano suction holes in the top silicon layer of SOI Cu impurity different doses (5 × 1013,5 × 1014,5 × 1015cm-2) in addition. cross-section Transmission electron microscopy (XTEM) and secondary ion mass spectrometry (SIMS) analysis showed that Cu impurities reach the silicon substrate through different oxide buried layers of SIMOX and Smart-Cut materials and are adsorbed by nano-pores at 700 ℃ .SIMOX oxidation intrinsic defects buried layer having the interface of Cu adsorption of certain impurities, the gettering effect is far below the nanopore gettering impurity and high temperature will release the buried oxide layer interface is complete .Smart-cut SOI, not after annealing includes .1000 ℃ gettering effect, nanopores can adsorb up to 3.5 × 1015cm-2 or more impurities of Cu, gettering efficiency nanopores with decreasing Cu implantation dose increases. when the top silicon layer is less than 5 × Cu dose 1014 cm-2, nano-hole gettering efficiency of more than 90%, and the top silicon in the impurity concentration of Cu reduced to the original 4 % Or less.Nitroporous gettering is an effective way to solve the problem of SOI impurity removal.