US 12,328,891 B2
Silicon-on-insulator (SOI) device having variable thickness device layer and corresponding method of production
Manoj Chandrika Reghunathan, Kulim (MY); Devesh Kumar Datta, Butterworth Penang (MY); Eric Alois Graetz, Penang (MY); Muhammad Akmal Hasanudin, Selangor (MY); and Vijay Anand Ramadass, Penang (MY)
Assigned to Infineon Technologies Austria AG, Villach (AT)
Filed by Infineon Technologies Austria AG, Villach (AT)
Filed on Aug. 30, 2022, as Appl. No. 17/898,836.
Prior Publication US 2024/0072159 A1, Feb. 29, 2024
Int. Cl. H10D 30/01 (2025.01); H01L 21/02 (2006.01); H10D 30/65 (2025.01); H10D 30/80 (2025.01); H10D 62/10 (2025.01); H10D 62/13 (2025.01); H10D 87/00 (2025.01)
CPC H10D 30/051 (2025.01) [H01L 21/02532 (2013.01); H01L 21/02642 (2013.01); H10D 30/0281 (2025.01); H10D 30/657 (2025.01); H10D 30/80 (2025.01); H10D 62/111 (2025.01); H10D 62/115 (2025.01); H10D 62/126 (2025.01); H10D 62/149 (2025.01); H10D 62/154 (2025.01); H10D 62/158 (2025.01); H10D 87/00 (2025.01)] 14 Claims
OG exemplary drawing
 
1. A method of producing power semiconductor devices from a silicon-on-insulator (SOI) wafer that includes a silicon device layer, a bulk silicon wafer, and a buried oxide layer separating the silicon device layer from the bulk silicon wafer, the method comprising:
forming a hard mask on the silicon device layer, wherein the hard mask covers one or more first regions of the silicon device layer and exposes one or more second regions of the silicon device layer; and
before forming any field oxide structures and before implanting any device regions, selectively growing epitaxial silicon on the one or more second regions of the silicon device layer exposed by the hard mask such that the thickness of the one or more second regions is increased relative to the one or more first regions.