Effect of Processing Conditions on the Surface Morphology of thin Polysilicon Films Used for Dram Cell Capacitors

Abstract

AbstractThe surface texture of polysilicon films, used for capacitor storage nodes, have been investigated for various deposition conditions. An increase in capacitance of approx. 70% has been observed in this work. The reproducibility of the surface texture and the resulting capacitance can be improved by optimizing the deposition pressure. The gain in capacitance was also observed to be affected by the thickness of the film. In the mass flow controlled regime the increase in capacitance was 12%. The increase in surface roughness and the gain in capacitance for the hot wall process provides a simple alternative for satisfying the charge capacity requirements in high density dynamic random access memories.