Advanced Micro Devices, Inc.
Oscillating capacitor architecture in polysilicon for improved capacitance

Abstract:

A system and method for fabricating metal insulator metal capacitors while managing semiconductor processing yield and increasing capacitance per area are described. A semiconductor device fabrication process places a polysilicon layer on top of an oxide layer which is on top of a metal layer. The process etches trenches into areas of the polysilicon layer where the repeated trenches determine a frequency of an oscillating wave structure to be formed later. The top and bottom corners of the trenches are rounded. The process deposits a bottom metal, a dielectric, and a top metal on the polysilicon layer both on areas with the trenches and on areas without the trenches. A series of a barrier metal and a second polysilicon layer is deposited on the oscillating structure. The process completes the MIM capacitor with metal nodes contacting each of the top metal and the bottom metal of the oscillating structure.