US 2018/0294278 A1 · DOPING CHANNELS OF EDGE CELLS TO PROVIDE UNIFORM PROGRAMMING SPEED AND REDUCE READ DISTURB

Abstract

A three-dimensional stacked memory device provides uniform programming speeds for a block of memory cells. The channel layers of the memory strings which are relatively close to a local interconnect of a stack are doped to account for a reduced blocking oxide thickness. Channel layers of remaining memory strings are undoped. The doping can be performing by masking the channel layers which are to remain undoped while exposing the other memory holes to a dopant. The dopant can be provided, e.g., in a carrier gas, spin on glass or other solid, or by plasma doping. An n-type dopant such as antimony, arsenic or phosphorus may be used. Heating causes the dopants to diffuse into the channel layer. Another approach deposits doped silicon for some of the channel layers and undoped silicon for other channel layers.

Claims20

Dependent claims

A memory device, comprising:

a plurality of word line layers which are vertically spaced apart from one another by dielectric layers in a stack;
and
a set of memory strings extending through the plurality of word line layers, the set of memory strings are arranged between first and second isolation regions which extend vertically in the stack, the set of memory strings comprises memory strings in a first edge region of the stack adjacent to the first isolation region, a second edge region of the stack adjacent to the second isolation region, and an interior region between the first and second edge regions, the memory strings in the first and second edge regions comprising doped channels and the memory strings in the interior region comprising undoped channels.

Dependencies are inferred from the claim text.

Doping channels of edge cells to provide uniform programming speed and reduce read disturb

Life of this patent

Doping channels of edge cells to provide uniform programming speed and reduce read disturb

Life of this patent

Abstract

Claims20