US 12,087,585 B2
Low-temperature implant for buried layer formation
Qintao Zhang, Mt Kisco, NY (US); Samphy Hong, Saratoga Springs, NY (US); Wei Zou, Lexington, MA (US); and Judy Campbell Soukup, Saratoga Springs, NY (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jun. 29, 2021, as Appl. No. 17/362,946.
Prior Publication US 2022/0415657 A1, Dec. 29, 2022
Int. Cl. H01L 21/00 (2006.01); H01L 21/265 (2006.01); H01L 21/266 (2006.01)
CPC H01L 21/26593 (2013.01) [H01L 21/26533 (2013.01); H01L 21/266 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method, comprising:
providing an opening through a mask, wherein the mask is a photoresist formed directly atop an exposed top surface of a substrate;
forming a buried layer in the substrate by directing ions through the opening of the mask while maintaining the substrate at a temperature of less than or equal to 0 degrees Celsius, wherein the ions are directed into the exposed top surface of the substrate, and wherein no oxide layer is present beneath the mask while the ions are directed into the exposed top surface of the substrate;
removing the mask;
forming an oxide layer over the substrate including over the buried layer; and
annealing the substrate and the oxide layer after the mask is removed and while an upper surface of the oxide layer remains entirely exposed, wherein the oxide layer extends into the buried layer, beneath the top surface of the substrate.