A Preliminary Analysis on Surface Contamination of Silicon Wafer by Cu and Fe
微量铜-铁对硅片表面污染的初步分析

Through a comparison of surface contamination of p-type silicon wafer by trace amounts of copper and iron when they are present in solutions separately or simultaneously,a preliminary study is conducted to investigate the non-contaminated or contaminated silicon wafer by employing electrochemical DC polarization and AC impedance techniques,as well as modern surface analysis technologies including SEM,EDX,and AES.It is revealed that in hydrofluoric acid solutions containing both ppb-level of copper and iron,not only would copper deposition take place,but also could carbon contamination occur at the wafer surface.General analysis and discussion in copper and carbon contamination are provided based on the polarization resistance,elemental depth distribution,and space charge effect.