Study of Chemical Polishing of InSb Wafers
InSb晶片化学抛光研究

Mechanical polishing can result in mechanical damage at the surface of an InSb wafer to a certain extent, increase the surface roughness of the wafer and affect the performance of the final device. However, chemical polishing can remove the surface scratch of the wafer and decrease the surface roughness. The InSb wafer is polished mechanically and further polished with a low concentration Br2 MeOH solution. The morphology, total thickness variation (TTV), ro吨h时邸, surface composition and impurity of the polished and unpolished InSb wafers are compared. The result shows that when the InSb wafer is polished with a low concentration Br2-MeOH solution, the erosion rate is stable and can be controlled easily and the surface scratch can be removed effectively and hence a fiat mirror-like surface can be obtained. The chemically polished wafer has its surface roughness of 6.443nm, a TTV of 3 .4 μm and an atomic ratio of In/Sb close to unity. Compared with the tra仙ωnal CP4-A and CP4-B etchi吨solution ,the low concentration Br2-MeOH solution is more suitable for polishing the InSb wafers chemically.