US 12,133,388 B2
Three-dimensional memory device with self-aligned etch stop rings for a source contact layer and method of making the same
Kota Funayama, Yokkaichi (JP); Satoshi Shimizu, Yokkaichi (JP); and Koichi Matsuno, Fremont, CA (US)
Assigned to SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed by SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed on Jan. 25, 2022, as Appl. No. 17/583,456.
Prior Publication US 2023/0240070 A1, Jul. 27, 2023
Int. Cl. H10B 43/27 (2023.01); H10B 41/27 (2023.01)
CPC H10B 43/27 (2023.02) [H10B 41/27 (2023.02)] 14 Claims
OG exemplary drawing
 
1. A memory device, comprising:
a layer stack including a lower source-level semiconductor layer, a source contact layer, and an upper source-level semiconductor layer;
an alternating stack of insulating layers and electrically conductive layers located over the layer stack; and
a memory opening fill structure vertically extending through the alternating stack, the upper source-level semiconductor layer, the source contact layer, and an upper portion of the lower source-level semiconductor layer,
wherein the memory opening fill structure comprises:
a vertical semiconductor channel vertically extending through the alternating stack and into the upper portion of the lower source-level semiconductor layer;
a memory film laterally surrounding the vertical semiconductor channel and vertically extending through the alternating stack and into an upper portion of the upper source-level semiconductor layer; and
a first annular semiconductor cap contacting a bottom surface of the memory film and contacting a top surface segment of the source contact layer.