Patent ID: 7541293

Claim:
A method for manufacturing a semiconductor device, comprising: using a chemical deposition technique, forming a processed film on a front side of a wafer having a trench pattern, the processed film being deposited such that a first portion of the processed film formed on a central portion of the wafer has a different thickness than a second portion of the processed film formed on an outer peripheral portion of the wafer; wet-etching the processed film on the wafer, wherein the step of wet-etching includes rotating the wafer and discharging a controlled amount of etchant at a high temperature on a thicker one of the first portion or the second portion of the processed film formed on the wafer; and while wet-etching, discharging a cooling gas onto a backside of the outer peripheral portion of the wafer to lower the temperature of the wafer in proximity to the outer peripheral portion of the wafer to control the etching of the processed film such that a remaining portion of the processed film has a uniform thickness.