Patent ID: 7351642

Claim:
A method for planarizing non-uniform shallow trench isolation films comprising: a. polishing a wafer first with a chemical mechanical polish process to planarize the surface of the wafer following a shallow trench isolation process; and b. etching a radial thickness non-uniformity of a film in a spin etching process further comprising: i. mounting the wafer on a spin susceptor to center a rotational thickness non-uniformity in the film disposed on the wafer about the axis of the spin susceptor, the wafer being mounted off-center on the spin susceptor to remove a film non-uniformity that is radial and misaligned with the center of the wafer; ii. adjusting a rotational speed of the wafer on the spin susceptor; iii. varying a position of a nozzle along the radius of the wafer to apply an etching solution to the wafer; iv. modifying the flow of the etching solution through the nozzle; and v. coordinating the rotational speed of the wafer and the position of the nozzle to maximize the removal of layer material contributing to the film non-uniformity.