Integrated trench MOSFET with trench Schottky rectifier

An integrated circuit comprising a plurality of trench MOSFETs and a plurality of trench Schottky rectifiers horizontally disposed in two different areas in said integrated circuit further comprises:

• a substrate of a first conductivity type;
• an epitaxial layer of said first conductivity type over said substrate, wherein said epitaxial layer has a lower doping concentration than said substrate;
• an insulation layer covering top surface of said epitaxial layer;
• each of said trench MOSFETs formed into the first area of said integrated circuit, further comprising:
• a plurality of first trenched gates formed within said epitaxial layer, wherein each of said first trenched gates filled with doped poly-silicon padded by a gate oxide layer;
• a body region of a second conductivity type surrounding each of said first trenched gate between every two adjacent of said first trenched gates and locating in upper portion of said epitaxial layer;
• a source region of said first conductivity type surrounding upper portion of each of said first trenched gates and locating near upper surface of said body region, said source region has a higher doping concentration than said first epitaxial layer;
• a plurality of trenched source-body contacts, wherein each of said trenched source-body contacts is filled with a metal plug and penetrating through said insulation layer, said source region and extending into said body region between every two adjacent of said first trenched gates;
• each of said trench Schottky rectifiers formed into the second area of said integrated circuit, wherein said source and body regions not existing, further comprises:
• a plurality of second trenched gates formed within said epitaxial layer without surrounding by said source and body regions, wherein each of said second trenched gates filled with said doped poly-silicon padded by said gate oxide layer;
• a plurality of trenched Schottky anode contacts, wherein each of said trenched Schottky anode contacts filled with said metal plug and penetrating through said insulation layer and extending into said epitaxial layer between every two adjacent of said second trenched gates wherein said source and body regions do not exist from top surface of said epitaxial layer down to said substrate;
• said trench Schottky rectifier having a Schottky barrier layer lined in said trenched Schottky anode contacts;
• and
• a drain metal for said trench MOSFET and also served as cathode metal for said Schottky rectifier disposed on rear side of said substrate.