US 12,457,731 B2
Bottom contact formation for 4F2 vertical DRAM
Sipeng Gu, Clifton Park, NY (US); Qintao Zhang, Mt Kisco, NY (US); and Kyu-Ha Shim, Andover, MA (US)
Assigned to Applied Materials, Inc.
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Oct. 11, 2022, as Appl. No. 17/963,555.
Prior Publication US 2024/0121937 A1, Apr. 11, 2024
Int. Cl. H10B 12/00 (2023.01); H10D 30/01 (2025.01)
CPC H10B 12/056 (2023.02) [H10D 30/024 (2025.01)] 17 Claims
OG exemplary drawing
 
1. A method, comprising:
providing a plurality of fins extending from a substrate in a first direction;
forming a spacer layer over the plurality of fins;
etching the substrate to expose a base portion of the plurality of fins, wherein a thickness, in a second direction, of the base portion of the plurality of fins and an upper portion of the plurality of fins is the same, and wherein the second direction is perpendicular to the first direction;
forming a conformal doped layer along an upper surface of the substrate and along the base portion of the plurality of fins having the same thickness as the upper portion of the plurality fins, wherein the conformal doped layer defines a trench; and
forming an oxide spacer over the conformal doped layer, including within the trench.