Patent attributes
An insulated-gate field effect transistor with the structure capable of weakening an electric field near or around the drain thereof. To this end, the transistor of the top gate type has its gate electrode which is formed of two kinds of metal layers (4, 5) capable of being anodized while carefully selecting materials and anodization process conditions in such a way as to let anodization of the lowermost metal layer (4) be faster in progress than that of its overlying metal layer (5). This ensures that an intensity-decreased electric field is applied to a portion (20) underlying an anodized part of the lower metal layer not only through a gate insulation film (3) but also through an anodized oxide (17). A weak inversion layer as created by this electric field may cause the electric field to decrease in intensity near or around the drain.
