Method for selectively etching oxides

摘要

A method for selectively etching oxides from the face of a semiconductor layer 10 is disclosed herein. The semiconductor layer 10 has at least first and second oxide regions 12 and 14 formed on the surface thereof. The oxides 12 and 14 may be doped oxides such as BPSG or PSG and/or thermally treated oxides such as a thermally grown oxide or a deposited oxide which is subsequently annealed. Native and chemical oxides are also considered. The semiconductor wafer 10 is heated to a temperature greater than room temperature (e.g., about 25 DEG C.) and a vapor phase hydrogen fluoride etch is performed so that one of the oxides 14 etches away at a rate significantly higher than the other oxide region 12. Other systems and methods are also disclosed.