碳离子注入对硅片表面黏附性能的影响

为了改善单晶硅材料表面的黏附性能,对单晶硅片进行碳离子注入,注入剂量为2×10~(16)ions/cm~2,注入能量分别为40 keV和80 keV.采用X射线衍射、X光电子能谱仪和三维轮廓仪研究了碳离子注入前后硅片的晶体结构、化学组分及其面粗糙度,通过接触角测定仪和扫描探针显微镜测量了碳离子注入前后硅片表面的接触角和黏附力的大小.结果表明:碳离子注入改变了硅片表面的晶体结构,在表面形成富含碳和碳化硅的改性层,较注入前粗糙度和接触角分别增加70%～90%和1.7～1.8倍;随着碳离子注入能量的增大,疏水性的碳和碳化硅增多,粗糙度和接触角分别增加9.5%和3.4%.在33%和70%这2种相对湿度条件下,碳离子注入后硅片表面的黏附力分别减少54%～57%和34%～37.3%;碳离子注入能量增加,黏附力分别减小6.7%和4.8%.相对湿度从33%增加到70%时,单晶硅、注入能量为40 keV和80 keV的硅片表面的黏附力分别增加1.24,2.22,2.28倍.

Influence of the C~+-implantation on the Adhesion Properties of Silicon Wafer Surface

The surface adhesion properties of single crystal silicon materials were reduced apply-ing C+-implantation into single crystal silicon wafers with the dose of 2×10~(16) ions/cm~2 and en-ergies of 40 keV and 80 keV, respectively. The crystal structures, surface chemical composi-tions and surface roughness of silicon wafers before and after C~+-implantation were investiga-ted using X-ray diffractometer, XPS and high-accuracy 3D profiler. The contact angles and ad-hesion forces of silicon surfaces before and after C~+-implantation were measured by a contact angle instrument and scanning probe microscope(SPM). The results show that the crystal structure of silicon surface was changed by C~+-implantation and the modified layer rich in C and SiC was formed at the surface. The roughness and contact angle of the silicon surface after C~+-implantation were increased by 70%- 90% and 1.7-1.8 times. Hydrophobic C and SiC increased with the increasing of C~+-implantation energy. The roughness and contact angle were increased by 9.5% and 3.4%, respectively. At the humidities of 33% and 70%, the adhesion forces of silicon surfaces after C~+-implantation were decreased by 54%-57% and 34%-37.3% ,respectively. The adhesion forces were decreased by 6.7% and 4.80//oo with the increas-ing of C~+-implantation energy. The surface adhesion forces of the single crystal silicon wafer, silicon wafers with C~+-implantation energies of 40 keV and 80 keV were increased by 1.24,2. 22 and 2.28 times when the relative humidity were increased from 33% to 70%.