US 11,837,629 B2
Power semiconductor devices having gate trenches and buried edge terminations and related methods
Daniel J. Lichtenwalner, Raleigh, NC (US); Edward R. Van Brunt, Raleigh, NC (US); and Brett Hull, Raleigh, NC (US)
Assigned to Wolfspeed, Inc., Durham, NC (US)
Filed by Wolfspeed, Inc., Durham, NC (US)
Filed on Nov. 19, 2020, as Appl. No. 16/952,757.
Application 16/952,757 is a continuation of application No. 15/372,505, filed on Dec. 8, 2016, granted, now 10,861,931.
Prior Publication US 2021/0098568 A1, Apr. 1, 2021
Int. Cl. H01L 29/06 (2006.01); H01L 29/10 (2006.01); H01L 29/78 (2006.01); H01L 21/04 (2006.01); H01L 29/66 (2006.01); H01L 29/739 (2006.01); H01L 29/16 (2006.01); H01L 29/08 (2006.01)
CPC H01L 29/063 (2013.01) [H01L 21/046 (2013.01); H01L 29/0623 (2013.01); H01L 29/1095 (2013.01); H01L 29/66068 (2013.01); H01L 29/66734 (2013.01); H01L 29/7397 (2013.01); H01L 29/7811 (2013.01); H01L 29/7813 (2013.01); H01L 29/0615 (2013.01); H01L 29/0619 (2013.01); H01L 29/0696 (2013.01); H01L 29/0878 (2013.01); H01L 29/1037 (2013.01); H01L 29/1608 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method of forming a semiconductor device, the method comprising:
forming a wide band-gap semiconductor drift region on a substrate, the drift region and the substrate each doped with dopants having a first conductivity type;
implanting second conductivity type dopants into an upper surface of the drift region to form a termination structure in a termination region of the semiconductor device and a shielding pattern in an active region of the semiconductor device, the second conductivity type being opposite the first conductivity type;
forming a first conductivity type semiconductor layer on the upper surface of the drift region via epitaxial growth, the semiconductor layer having a first conductivity dopant concentration of less than 1×1016/cm3 in the completed semiconductor device; and
implanting second conductivity type dopants into the semiconductor layer in the active region to form well regions of the second conductivity type.