US 11,658,033 B2
Methods of forming assemblies having heavily doped regions
Yushi Hu, McLean, VA (US); and Shu Qin, Boise, ID (US)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Nov. 17, 2020, as Appl. No. 16/950,115.
Application 16/950,115 is a division of application No. 16/292,021, filed on Mar. 4, 2019, granted, now 10,879,071.
Application 16/292,021 is a division of application No. 14/927,217, filed on Oct. 29, 2015, granted, now 10,256,098, issued on Apr. 9, 2019.
Prior Publication US 2021/0082703 A1, Mar. 18, 2021
Int. Cl. H01L 21/225 (2006.01); H01L 21/28 (2006.01); H01L 27/11556 (2017.01); H01L 27/11582 (2017.01)
CPC H01L 21/2253 (2013.01) [H01L 21/28 (2013.01); H01L 27/11556 (2013.01); H01L 27/11582 (2013.01); H01L 29/40114 (2019.08); H01L 29/40117 (2019.08)] 10 Claims
OG exemplary drawing
 
1. A method of forming an assembly, comprising:
forming a heavily-doped region along a surface of a first semiconductor material;
forming a protective material over the heavily-doped region;
forming a stack over the protective material;
etching through the stack to the protective material to form an opening through the stack and expose a region of the protective material;
oxidizing protective material within the exposed region to form an oxide;
forming lightly-doped second semiconductor material within the opening; and
out-diffusing dopant from the heavily-doped region, through the oxide and into the second semiconductor material; the out-diffusing forming a heavily-doped lower region within the second semiconductor material adjacent the oxide while leaving a lightly-doped upper region of the second semiconductor material above the heavily-doped lower region; the lightly-doped upper region and heavily-doped lower region being majority doped to a same dopant type, and joining to one another along a boundary region.