US 11,706,925 B2
Methods of forming electronic devices with channel openings or pillars extending through a tier stack
John D. Hopkins, Meridian, ID (US); Nancy M. Lomeli, Boise, ID (US); Justin B. Dorhout, Boise, ID (US); and Damir Fazil, Boise, ID (US)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Nov. 7, 2022, as Appl. No. 18/53,134.
Application 18/053,134 is a division of application No. 17/032,384, filed on Sep. 25, 2020, granted, now 11,495,617.
Application 17/032,384 is a division of application No. 16/157,927, filed on Oct. 11, 2018, granted, now 10,825,828, issued on Nov. 3, 2020.
Prior Publication US 2023/0092501 A1, Mar. 23, 2023
Int. Cl. H10B 43/27 (2023.01); H10B 43/35 (2023.01); H10B 43/40 (2023.01); H10B 41/27 (2023.01); H10B 41/35 (2023.01); H10B 41/41 (2023.01); H01L 21/311 (2006.01); H01L 21/02 (2006.01)
CPC H10B 43/27 (2023.02) [H10B 41/27 (2023.02); H10B 41/35 (2023.02); H10B 41/41 (2023.02); H10B 43/35 (2023.02); H10B 43/40 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A method of forming a semiconductor device, the method comprising:
forming a stack of vertically-alternating tiers of insulative material and other material over a base material, a sacrificial material disposed in the base material, and a soft plug material disposed in the sacrificial material;
forming an opening extending through the stack and through the soft plug material, leaving remnants of the soft plug material along sidewalls of the opening;
forming a liner in the opening;
exposing, through the liner, a portion of the sacrificial material;
without removing the liner, removing the sacrificial material and the remnants of the soft plug material to define a gap between the liner and a sidewall of the base material, the gap exposing a portion of a lower tier of the stack;
etching into the portion of the lower tier of the stack to define an undercut portion in the lower tier of the stack; and
removing the liner to form a channel opening extending through the stack and into the base material, the channel opening exposing a source region of the base material at a base of the channel opening, the channel opening defined by sidewalls comprising the undercut portion.
 
7. A method of forming a semiconductor device, the method comprising:
forming a first deck of vertically-alternating tiers of insulative material and other material over a base material and a sacrificial material disposed in the base material;
forming an opening extending through the first deck and into the sacrificial material;
forming a liner and a fill material within the opening;
forming a second deck of vertically-alternating tiers of the insulative material and the other material over the first deck, the liner, and the fill material;
forming another opening extending through the second deck to the fill material within the opening;
forming another liner within the other opening;
exposing a portion of the fill material through the other liner;
without removing the liner or the other liner, removing the fill material and the sacrificial material to form an extended opening exposing at least a portion of a lower tier of each of the first deck and the second deck;
isotropically etching the portion of the lower tier of each of the first deck and the second deck to define undercut portions; and
removing the liner and the other liner to form a channel opening defined by sidewalls comprising the undercut portions.
 
10. A method of forming an electronic device, comprising:
forming a deck above at least one sacrificial material, the deck comprising insulative structures vertically alternating with other structures and arranged in tiers;
forming an opening through the deck and to or into the at least one sacrificial material;
forming a liner in the opening along sidewalls of the deck;
without substantially removing sidewalls of the liner, removing at least a portion of the at least one sacrificial material to expose a portion of a lower surface of a lowest insulative structure of the insulative structures of the deck;
etching into the portion of the lower surface of the lowest insulative structure of the insulative structures of the deck; and
removing the liner to form a channel opening tapering through the tiers of the deck above the lowest insulative structure, the channel opening broadening at the lowest insulative structure.