Patent ID: 7456070
Filing Date: 2008-11-25
Classification: H01L

Abstract:
1. A method for making a transistor, comprising the steps of: masking the surface of a semiconductor body to cover regions of said surface; doping unmasked regions of said surface to form a plurality of spaced apart diffusion source regions; diffusing dopants from said diffusion source regions to cause said diffusion source regions to combine with each other and form a single doped buried region having portions of said single doped buried region having a first thickness and portions of said single doped buried region having a second thickness, said first thickness less than said second thickness; forming an electron collecting region over said doped buried region; forming an electron control region within said electron collecting region; and forming an electron emitting region within said electron control region; each of said electron collecting region, said electron control region and said electron emitting region having a portion disposed over said buried region having said first thickness and at least a portion of said electron control region extending over said portion having said second thickness, wherein said buried region having said first thickness is a diffusion-overlapping region.