US 11,888,024 B2
Method of forming a semiconductor device
Reinhard Ploss, Unterhaching (DE); and Hans-Joachim Schulze, Taufkirchen (DE)
Assigned to Infineon Technologies AG, Neubiberg (DE)
Filed by Infineon Technologies AG, Neubiberg (DE)
Filed on Aug. 17, 2021, as Appl. No. 17/404,278.
Application 17/404,278 is a continuation of application No. 16/455,960, filed on Jun. 28, 2019, granted, now 11,139,369.
Application 16/455,960 is a continuation of application No. 15/385,137, filed on Dec. 20, 2016, granted, now 10,340,335, issued on Jul. 2, 2019.
Claims priority of application No. 10 2015 122 833.5 (DE), filed on Dec. 23, 2015.
Prior Publication US 2021/0376068 A1, Dec. 2, 2021
Int. Cl. H01L 29/06 (2006.01); H01L 21/04 (2006.01); H01L 21/225 (2006.01); H01L 21/263 (2006.01); H01L 21/265 (2006.01); H01L 21/3065 (2006.01); H01L 21/324 (2006.01); H01L 29/16 (2006.01); H01L 21/3115 (2006.01); H01L 29/32 (2006.01); H01L 29/167 (2006.01)
CPC H01L 29/0634 (2013.01) [H01L 21/046 (2013.01); H01L 21/0455 (2013.01); H01L 21/0475 (2013.01); H01L 21/2253 (2013.01); H01L 21/2255 (2013.01); H01L 21/263 (2013.01); H01L 21/26513 (2013.01); H01L 21/3065 (2013.01); H01L 21/324 (2013.01); H01L 29/16 (2013.01); H01L 29/1608 (2013.01); H01L 21/31155 (2013.01); H01L 29/167 (2013.01); H01L 29/32 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method of forming a semiconductor device, the method comprising:
forming a trench in a semiconductor body at a first surface of the semiconductor body;
at least partially filling the trench with a filling material, the filling material having a bottom side and a top side;
introducing dopants into a portion of the filling material to form a doped filling material, wherein the dopants have a first diffusion coefficient relative to the filling material and have a second diffusion coefficient relative to the semiconductor body, wherein the first diffusion coefficient is greater than the second diffusion coefficient;
applying a first thermal processing to the doped filling material, the first thermal processing having a first temperature profile configured to spread the dopants within the doped filling material along a vertical direction between the bottom side and the top side of the doped filling material by a diffusion process, thereby shaping a vertical doping profile of the dopants within the doped filling material, wherein the first temperature profile is configured such that the dopants are substantially confined to within the trench and substantially do not diffuse from the doped filling material into the semiconductor body during the first thermal processing; and
subsequent to applying the first thermal processing, applying a second thermal processing to the semiconductor body configured having a second temperature profile to cause diffusion of the dopants from the doped filling material having the shaped vertical doping profile into a region of the semiconductor body adjoining the trench, wherein the diffused dopants from the filling material cause counter-doping of the semiconductor body, and
wherein introducing the dopants into the portion of the filling material to form the doped filling material includes introducing the dopants at different vertical depths within the filling material inside the trench.