Patent ID: 7981759
Filing Date: 2011-07-19
Classification: H01G,H01L

Abstract:
1. A method for fabricating a patterned polysilicon layer having a planar surface, comprising: depositing a polysilicon film above a substrate material; depositing an oxide-resistant mask over the polysilicon film; patterning and etching the oxide-resistant mask to form a patterned mask layer over the polysilicon film, such that the polysilicon film includes masked and unmasked portions; etching the unmasked portion of the polysilicon film for a first amount of time to define a pattern in the masked portion of the polysilicon film; oxidizing the etched polysilicon film for a second amount of time to form an oxide layer that is coplanar with the patterned polysilicon film; removing the patterned mask layer; fabricating a tunable capacitor over the patterned polysilicon layer; wherein the first and second amounts of time are selected such that the oxide layer and the patterned polysilicon film have about the same thickness and form a planar surface.