Patent ID: 6072216
Filing Date: 2000-06-06
Classification: H01L,Y10S

Abstract:
A vertical power MOSFET comprising:a semiconductor substrate of a first conductivity type;a lightly doped epitaxial layer generally of the first conductivity type overlying the substrate, the lightly doped layer being doped relatively lightly with dopant of the first conductivity type as compared with the substrate;a MOSFET cell comprising:a body region of a second conductivity type opposite to the first conductivity type within the epitaxial layer, the body region being located adjacent a surface of the epitaxial layer and enclosing and defining a central portion of the MOSFET cell;a source region of the first conductivity type enclosed by and forming a junction with the body region, a portion of the body region adjacent the surface of the epitaxial layer comprising a channel region;a drain region of the first conductivity type comprising the substrate;a gate separated from the channel region by a dielectric layer; anda buried layer located within the epitaxial layer and extending into the substrate, the buried layer being of the first conductivity type and having a higher concentration of a dopant of the first conductivity type than a remaining portion of the epitaxial layer, the buried layer having an upper boundary within the epitaxial layer, the upper boundary having a shape such the upper boundary is at a first level below the body region and at a second level at a center of the MOSFET cell, the second level being above the first level.