US 12,255,242 B2
Three-dimensional memory device including vertical stack of tubular graded silicon oxynitride portions
Adarsh Rajashekhar, Santa Clara, CA (US); Raghuveer S. Makala, Campbell, CA (US); and Koichi Matsuno, Fremont, CA (US)
Assigned to Sandisk Technologies Inc., Milpitas, CA (US)
Filed by SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed on Jan. 28, 2022, as Appl. No. 17/587,470.
Prior Publication US 2023/0246084 A1, Aug. 3, 2023
Int. Cl. H01L 29/423 (2006.01); H01L 21/28 (2006.01); H01L 29/792 (2006.01); H10B 43/27 (2023.01)
CPC H01L 29/4234 (2013.01) [H01L 29/40117 (2019.08); H01L 29/792 (2013.01); H10B 43/27 (2023.02)] 14 Claims
OG exemplary drawing
 
1. A semiconductor structure, comprising:
an alternating stack of insulating layers and electrically conductive layers;
a memory opening vertically extending through the alternating stack; and
a memory opening fill structure located in the memory opening and comprising a vertical semiconductor channel, a memory film in contact with the vertical semiconductor channel, and a vertical stack of tubular graded silicon oxynitride portions laterally surrounding the memory film and having a composition gradient such that an atomic concentration of nitrogen decreases with a lateral distance from an outer sidewall of the memory film,
wherein the memory film comprises a dielectric metal oxide blocking dielectric layer; and
wherein each of the electrically conductive layers has a hammerhead-shaped vertical cross-sectional profile such that a vertical extent of each of the electrically conductive layers has a local minimum within a cylindrical volume laterally bounded by outer sidewall segments of the memory opening fill structure.