IP Library Granted Patent US 9,263,132
Granted Patent B2
US 9,263,132 · App. 13/206,780 · Granted Feb 16, 2016

Double gated flash memory

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Quick Facts
Patent No.
US 9,263,132
App. No.
13/206,780
Granted
Feb 16, 2016
Kind
B2
Abstract

A split gate memory cell is fabricated with a fin structure between a memory gate stack and a select gate. Embodiments include a first channel region under the memory gate stack and a second channel region under the select gate.

Claims (41)

1. A method comprising:

etching to form a fin structure on a substrate;

depositing a hard mask material on the fin structure;

forming an oxide over the substrate;

etching the oxide to expose an upper portion of the fin structure;

removing the hard mask material;

performing an isolation and well implantation to form a well;

providing a memory gate stack and a first tunneling oxide layer along a first side surface of the fin structure; and

providing a select gate and a second tunneling oxide layer along a second side surface of the fin structure,

wherein providing the memory gate stack and the select gate stack includes:

depositing a floating gate material on the first side surface of the fin structure;

depositing a select gate material on the second side surface of the fin structure;

planarizing the floating gate material and the select gate material to be substantially coplanar with an upper surface of the fin structure; and

depositing a control gate material proximate a side surface of the floating gate material,

wherein an upper surface of the control gate material is substantially coplanar with the upper surface of the fin structure.

2. The method according to claim 1 , comprising:

providing a first channel region under the memory gate stack; and

providing a second channel region under the select gate.

3. The method according to claim 2 , wherein the first channel region is for program and/or erase and the second channel region is for read.

4. The method according to claim 1 , comprising providing the memory gate stack and the select gate on opposite side surfaces of the fin structure.

5. The method according to claim 1 , wherein the floating gate material is the same as the select gate material.

6. The method according to claim 1 , comprising:

oxidizing the first and second side surfaces of the fin structure prior to depositing the floating gate and the select gate material; and

forming a dielectric layer on a side surface of the floating gate material prior to depositing the control gate material.

7. The method according to claim 4 , comprising:

providing a second fin structure proximate the select gate; and

providing a second memory gate stack proximate a side surface of the second fin structure, opposite the select gate.

8. The method according to claim 4 , comprising:

providing a second memory gate stack on the substrate proximate, but separated from the select gate;

providing a second fin structure proximate the second memory gate stack; and

providing a second select gate proximate the second fin structure, opposite the second memory gate stack.

9. A method comprising:

etching a substrate to form a first fin structure and a second fin structure, separated from the first fin structure;

forming an oxide over the substrate;

timed etching the oxide to expose an upper portion of the first and second fin structures;

oxidizing the exposed upper portion of the first and second fin structures;

depositing a select gate material between oxidized portions of the first and second fin structures, proximate a first side surface of each of the first and second fin structures;

depositing a floating gate material proximate oxidized portions of a second side surface of each of the first and second fin structures;

planarizing the select gate material, the floating gate material, and the first and second fin structures to be substantially coplanar;

forming a first dielectric layer proximate a side surface of the floating gate material proximate the first fin structure and a second dielectric layer proximate a side surface of the floating gate material proximate the second fin structure; and

depositing a control gate material proximate the first and second dielectric layers.

Assignments (3)
RELEASE OF SECURITY INTEREST Recorded Nov 19, 2020
From: WILMINGTON TRUST, NATIONAL ASSOCIATION
To: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
Reel/Frame 054481/0673 →
SECURITY AGREEMENT Recorded Nov 27, 2018
From: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
To: WILMINGTON TRUST, NATIONAL ASSOCIATION
Reel/Frame 047660/0203 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 10, 2011
From: TAN, SHYUE SENG (JASON); TOH, ENG HUAT; QUEK, ELGIN
To: GLOBALFOUNDRIES SINGAPORE PTE. LTD.
Reel/Frame 026727/0887 →