Method of Making MOSFET Integrated with Schottky Diode with Simplified One-time Top-Contact Trench Etching

A method for fabricating a MOSFET integrated with Schottky diode (MOSFET/SKY), expressed in an X-Y-Z Cartesian coordinate system with the X-Y plane parallel to its major semiconductor chip plane, comprising:

• a) forming, in an epitaxial layer overlaying a semiconductor substrate, a gate trench and depositing gate material therein;
• b) forming a body region in the epitaxial layer, a source region atop the body region and a dielectric region atop the gate trench and the source region;
• c) etching a top contact trench (TCT) with vertical side walls defining a X-Y cross sectional boundary for containing a Schottky diode there within, said X-Y cross sectional boundary
• c1) going through the dielectric region and the source region thus defining a source-contact depth (SCD);
• and
• c2) going partially into the body region by a predetermined total body-contact depth (TBCD);
• d) creating:
• d1) into the side walls of the TCT and beneath the SCD, a heavily-doped embedded body implant region (EBIR) of body-contact depth (BCD)<TBCD;
• and
• d2) into a sub-contact trench zone (SCTZ) beneath the floor of the TCT, an embedded Shannon implant region (ESIR);
• and
• e) forming a metal layer:
• e1) in contact with the ESIR, the body region and the source region;
• and
• e2) filling the TCT and covering the dielectric region whereby completing the MOSFET/SKY with only one-time etching of its TCT.