Patent ID: 6610569
Filing Date: 2003-08-26
Classification: H01L

Abstract:
A process of producing a semiconductor device, comprising:forming a first polycrystalline silicon layer overlying a silicon oxide layer; doping impurity into said first polycrystalline silicon layer; forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; after said doping impurity into said first polycrystalline silicon layer, forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer being thicker than the first polycrystalline silicon layer and being adapted to be charged with substantially a same voltage as that of the first polycrystalline silicon layer; and doping impurity into said second polycrystalline silicon layer, wherein the impurity doped into the first and second polycrystalline silicon layers is a p-type impurity.