Patent ID: 6569715
Filing Date: 2003-05-27
Classification: H01L

Abstract:
A method of forming a semiconductor device, comprising the steps of:forming a large grain silicon film over a substrate, said large grain silicon film comprising crystals having grain boundaries primarily normal relative to a surface of said substrate; forming a first doped layer in an upper portion of the large grain silicon film; annealing said large grain silicon film and said first doped layer to simultaneously activate said first doped layer and form a second doped layer in a lower portion of the large grain silicon film, wherein an undoped region exists between said first doped layer and said second doped layer of said large grain silicon film; patterning and removing portions of the large grain silicon film and the first and second doped layers to form a vertical device stack, wherein said undoped region is over said second doped layer and said first doped layer is over said undoped region; forming a gate oxide layer on at least one side of the device stack; and forming a first gate over said gate oxide layer on said at least one side of the device stack.