HTO offset for long leffective, better device performance
First Claim
Patent Images
1. A dual-bit memory cell comprising:
- a charge trapping dielectric stack disposed overlying an essentially planar upper surface of a semiconductor substrate;
a poly gate disposed overlying the charge trapping dielectric stack;
p-type pocket implant regions having a first portion under a peripheral portion of the charge trapping dielectric stack and a second portion adjacent to the charge trapping dielectric stack and disposed in a bit line opening;
spacers laterally adjacent the charge trapping dielectric stack and poly gate, wherein a first portion of each spacer overlies the second portion of each pocket implant region;
a bit line implant region disposed in the semiconductor substrate adjacent the charge trapping dielectric stack and under the bit line opening wherein the bit line implant region has an upper surface congruent with the upper surface of the semiconductor surface; and
a word line.
7 Assignments
0 Petitions
Accused Products
Abstract
Memory devices having an increased effective channel length and/or improved TPD characteristics, and methods of making the memory devices are provided. The memory devices contain two or more memory cells on a semiconductor substrate and bit line dielectrics between the memory cells. The memory cell contains a charge trapping dielectric stack, a poly gate, a pair of pocket implant regions, and a pair of bit lines. The bit line can be formed by an implant process at a higher energy level and/or a higher concentration of dopants without suffering device short channel roll off issues because spacers at bit line sidewalls constrain the implant in narrower implant regions.
12 Citations
19 Claims
-
1. A dual-bit memory cell comprising:
-
a charge trapping dielectric stack disposed overlying an essentially planar upper surface of a semiconductor substrate; a poly gate disposed overlying the charge trapping dielectric stack; p-type pocket implant regions having a first portion under a peripheral portion of the charge trapping dielectric stack and a second portion adjacent to the charge trapping dielectric stack and disposed in a bit line opening; spacers laterally adjacent the charge trapping dielectric stack and poly gate, wherein a first portion of each spacer overlies the second portion of each pocket implant region; a bit line implant region disposed in the semiconductor substrate adjacent the charge trapping dielectric stack and under the bit line opening wherein the bit line implant region has an upper surface congruent with the upper surface of the semiconductor surface; and a word line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method of making dual-bit memory cells, comprising:
-
forming a charge trapping dielectric stack disposed overlying an essentially planar upper surface of a semiconductor substrate; forming a poly gate disposed overlying the charge trapping dielectric stack; forming p-type pocket implant regions in the semiconductor substrate, wherein the p-type pocket implant regions have a first portion under a peripheral portion of the charge trapping dielectric stack, and a second portion adjacent to the charge trapping dielectric stack and disposed in a bit line opening; forming spacers laterally adjacent the charge trapping dielectric stack and the poly gate wherein a first portion of each spacer overlies the second portion of each pocket implant region; forming a bit line implant region disposed in the semiconductor substrate adjacent the charge trapping dielectric stack and under the bit line opening wherein the bit line implant region has an upper surface congruent with the upper surface of the semiconductor substrate; forming a word line overlying the charge trapping dielectric stack. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A memory device, comprising:
-
an array of dual-bit memory cells, wherein each of the dual-bit memory cells comprises, a charge trapping dielectric stack disposed overlying an essentially planar upper surface of a semiconductor substrate, a poly gate disposed overlying the charge trapping dielectric stack, p-type pocket implant regions having a first portion under a peripheral portion of the charge trapping dielectric stack and a second portion adjacent to the charge trapping dielectric stack and disposed in a bit line opening, spacers laterally adjacent the charge trapping dielectric stack and poly gate, wherein a first portion of each spacer overlies the second portion of each pocket implant region, a bit line implant region disposed in the semiconductor substrate adjacent the charge trapping dielectric stack and under the bit line opening wherein the bit line implant region has an upper surface congruent with the upper surface of the semiconductor surface, and a word line; wherein the array of dual-bit memory cells is arranged in rows and columns such that, the charge trapping dielectric stack of each of the dual-bit memory cells includes one of the bit line openings and the bit line implant region disposed laterally adjacent on both sides, two of the dual-bit memory cells in a same row and adjacent columns are separated by and share a common bit line opening and bit line implant region, and the dual-bit memory cells in the same row share a common word line. - View Dependent Claims (17, 18, 19)
-
Specification