注入能量对硅片的表面性能影响的研究

Research on the Effects of Surface Performance of Silicon Wafers Under Different C^+ Implantation Energy

以单晶硅(111)作为研究对象,选用注入剂量为8×1015ions／cm2,注入能量分别为50,80和120 keV的C+注入方法对单晶硅片进行离子注入．利用原位纳米力学测试系统对C+注入前后硅片的纳米硬度和弹性模量进行测定,在UMT-2型微摩擦试验机上对C+注入前后硅片开展往复滑动微摩擦实验,研究其摩擦系数和声发射信号的变化,采用T-1000型表面轮廓仪测量C+注入前后硅片的磨损量,利用S-3000N型扫描电子显微镜表征C+注入前后硅片的磨损机理．结果表明,C+注入能量为50 keV硅片的纳米硬度和弹性模量大幅减小,而其他2种注入能量的纳米硬度和弹性模量与单晶硅相差较小;C+注入后硅片的减摩效果得到了提高,在小载荷下其摩擦系数大幅度降低,但在载荷达到一定值后,摩擦系数和声发射信号会迅速增加并且产生磨痕;注入能量为120 keV的硅片的减摩效果最佳,注入能量为80 keV和120 keV的硅片的抗磨性能较好;C+注入前后单晶硅片的磨损形貌在小载荷下以黏着磨损为主．

The single crystal silicon（111） wafers were taken as examples and implanted by carbon ion with an implantation dose of 8× 10^15 ions/cm^3 and different energies of 50, 80 and 120 keV, respectively. The nano-hardness and elastic modulus of silicon wafers were measured on the insitu nano mechanical testing system before and after C^＋ implantation. The reciprocating sliding tests on silicon wafers were performed on the UMT-2 Micro-tribometer, which attempted to investigate the variation of friction coefficient and acoustic emission energy before and after C^＋ implantation. Wear volumn of silicon wafers before and after C^＋ implantation were characterized using a T-1000 profilometer. The morphologies of worn surface were observed with the S- 3000N Scanning Electron Microscope in order to gain informations on the wear mechanisms. The results demonstrate that the nano-hardness and elastic modulus of silicon wafer under the implantation energy of 50 keV decreased to a gies of 80 and 120 keV were close to that of great extent. But those of the implantation enersingle crystal silicon. Friction-reducing effect of the C^＋ implanted silicon wafers improved and its coefficient of friction also decreased greatly under a light load. But when the load reached to a certain value, the coefficient of friction and acoustic emission energy increased sharply and the worn trace occurred on the wafer surface. The effects of friction-reducing of silicon wafer under implantation energies of 120 keV were the best and the silicon wafers under implantation energies of 80 keV and 120 keV exhibited the better anti-wear performance. Adhesive wear was the main mechanism under a light load for the silicon wafers before and after C^＋ implantation.