Patent ID: 6050506
Filing Date: 2000-04-18
Classification: C23C

Abstract:
A showerhead for distributing process gas to a substrate processing area in a chemical-vapor deposition apparatus, comprising a flat front faceplate having a gas cavity therebehind and having a number of holes therethrough arranged in a generally symmetric pattern about a central axis of said faceplate, said pattern comprising:a first plurality of said holes in a first zone occupying a central portion of said faceplate and being arranged with a first density of said holes;a second plurality of said holes in a second zone of said faceplate surrounding said first zone and being arranged with a second density of said holes greater than said first density; anda third plurality of said holes in a third zone of said faceplate surrounding said second zone and being arranged with a third density of said holes;wherein said first, second, and third densities differ by at least 10% among them.