US 12,113,101 B2
Method and system of junction termination extension in high voltage semiconductor devices
Subhash Srinivas Pidaparthi, Santa Clara, CA (US); Andrew P. Edwards, Santa Clara, CA (US); Clifford Drowley, Santa Clara, CA (US); and Kedar Patel, Santa Clara, CA (US)
Assigned to SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC, Scottsdale, AZ (US)
Filed by SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC, Scottsdale, AZ (US)
Filed on Jul. 7, 2021, as Appl. No. 17/369,600.
Claims priority of provisional application 63/049,562, filed on Jul. 8, 2020.
Prior Publication US 2022/0013626 A1, Jan. 13, 2022
Int. Cl. H01L 29/06 (2006.01); H01L 21/265 (2006.01); H01L 21/266 (2006.01); H01L 21/324 (2006.01); H01L 29/40 (2006.01)
CPC H01L 29/0615 (2013.01) [H01L 21/26546 (2013.01); H01L 21/266 (2013.01); H01L 21/3245 (2013.01); H01L 29/401 (2013.01); H01L 29/402 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A semiconductor device comprising:
a semiconductor substrate comprising a first side and second side, wherein the semiconductor substrate is characterized by a first conductivity type;
a first III-nitride epitaxial semiconductor layer epitaxially grown on the first side of the semiconductor substrate, wherein the first III-nitride epitaxial semiconductor layer is characterized by a varying dopant concentration of the first conductivity type;
a second III-nitride epitaxial semiconductor layer epitaxially grown on the first III-nitride epitaxial semiconductor layer, wherein the second III-nitride epitaxial semiconductor layer is characterized by the first conductivity type and an upper surface, wherein the second III-nitride epitaxial semiconductor layer comprises a contact region including a contact structure comprising a plurality of source contacts, each of the plurality of source contacts formed on a portion of the upper surface of the second III-nitride epitaxial semiconductor layer;
a plurality of fins formed in the second III-nitride epitaxial semiconductor layer and a portion of the first III-nitride epitaxial semiconductor layer, wherein bottom surfaces of the fins extend from the first III-nitride epitaxial semiconductor layer and each of the plurality of fins is separated from an adjacent fin of the plurality of fins by a trench;
a third III-nitride epitaxial semiconductor layer epitaxially regrown in the trenches separating the plurality of fins and defined by an upper surface coplanar with the upper surface of the second III-nitride epitaxial semiconductor layer and including a terminal region surrounding the contact region, wherein the terminal region comprises a tapered junction termination element having a linear profile and a non-conducting ion implanted zone adjacent to the tapered junction termination element, wherein the non-conducting ion implanted zone is characterized by the linear profile, and wherein the third III-nitride epitaxial layer is characterized by a second conductivity type opposite to the first conductive type; and
a gate metal layer formed on the upper surface of the third III-nitride epitaxial semiconductor layer.