Method of making MOSFET integrated with schottky diode with simplified one-time top-contact trench etching
US8748268B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2012 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Dec 20, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/661
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Method for fabricating MOSFET integrated with Schottky diode (MOSFET/SKY) is disclosed. Gate trench is formed in an epitaxial layer overlaying semiconductor substrate, gate material is deposited therein. Body, source, dielectric regions are successively formed upon epitaxial layer and the gate trench. Top contact trench (TCT) is etched with vertical side walls defining Schottky diode cross-sectional width SDCW through dielectric and source region defining source-contact depth (SCD); and partially into body region by total body-contact depth (TBCD). A heavily-doped embedded body implant region (EBIR) of body-contact depth (BCD)<TBCD is created into side walls of TCT and beneath SCD. An embedded Shannon implant region (ESIR) is created into sub-contact trench zone (SCTZ) beneath TCT floor. A metal layer is formed in contact with ESIR, body and source region. The metal layer also fills TCT and covers dielectric region thus completing the MOSFET/SKY with only one-time etching of its TCT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.