Process for operating an electronic device including a memory array and conductive lines

• US 7,262,997 B2
• Filed: 07/25/2005
• Issued: 08/28/2007
• Est. Priority Date: 07/25/2005
• Status: Expired due to Fees

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Yater, Jane A., Hong, Cheong M., Chindalore, Gowrishankar L.
• Primary Examiner(s): Phan; Trong
• Application Number:
  US11/188,898
• Publication Number:
  US 20070019472A1
• Time in Patent Office: 764 Days
• Field of Search: 365/185.03, 365/185.18, 365/185.26, 365/185.28, 365/182, 365/185.29, 257/316, 257/330, 257/304, 257/306, 257/314, 438/233, 438/240, 438/296, 438/299, 438/439
• US Class Current: 365/185.18
• CPC Class Codes: G11C 16/10 Programming or data input circuits

Abstract

An electronic circuit can include a first memory cell and a second memory cell. In one embodiment, source/drain regions of the first and second memory cells can be electrically connected to each other. The source/drain regions may electrically float regardless of direction in which carriers flow through channel regions of the memory cells. In another embodiment, the first memory cell can be electrically connected to a first gate line, and the second memory cell can be electrically connected to a greater number of gate lines as compared to the first memory cell. In another aspect, the first and second memory cells are connected to the same bit line. Such bit line can electrically float when programming or reading the first memory cell or the second memory cell or any combination thereof.

Claims

1. A process for operating an electronic device including a memory array comprising:

providing the electronic device, wherein the memory array comprises a first memory cell, wherein the first memory cell includes;

a substrate including a trench, wherein;

the trench extends into a semiconductor material;

the trench includes a ledge and a bottom; and

the bottom lies at a depth deeper than the ledge;

a first set of discontinuous storage elements, wherein the first set of the discontinuous storage elements lies within the trench;

a first gate electrode overlying the ledge; and

a second gate electrode overlying the bottom; and

programming a first memory cell using hot carrier injection, wherein a bit line is electrically connected to the first memory cell and electrically floats during programming the first memory cell.

2. The process of claim 1, further comprising:

reading the first memory cell, wherein the bit line electrically floats during reading the first memory cell.

3. The process of claim 2, further comprising:

erasing the first memory cell, wherein the bit line electrically floats during erasing the first memory cell.

4. The process of claim 1, wherein:

providing the electronic device comprises providing the electronic device, wherein the memory array further comprises a second memory cell; and

the process further comprises;

reading the second memory cell, wherein the bit line is electrically connected to the second memory cell and electrically floats during reading the second memory cell.

5. The process of claim 1, wherein the hot carrier injection comprises a source-side injection.

6. The process of claim 1, wherein:

providing the electronic device further comprises;

providing the electronic device, wherein the memory array further comprises a second memory cell;

providing a first doped region within a substrate, wherein the first doped region is part of the first memory cell;

providing a second doped region within the substrate, wherein the second doped region is part of the second memory cell; and

providing a third doped region within the substrate, wherein;

the third doped region lies between the first doped region and the second doped region;

the third doped region is spaced apart from each of the first doped region and the second doped region; and

the third doped region is part of the first and second memory cells; and

programming the first memory cell comprises flowing charge carriers between the first doped region and the second doped region.

7. The process of claim 6, wherein providing the electronic device comprises providing the electronic device, wherein:

the first set of discontinuous storage elements lies between the first gate electrode and the substrate, wherein each of the first gate electrode and the first set of discontinuous storage elements lies adjacent to the first and third doped regions; and

the second memory cell includes a third gate electrode and a second set of discontinuous storage elements lying between the third gate electrode and the substrate, wherein each of the third gate electrode and the second set of discontinuous storage elements lies adjacent to the second and third doped regions.

8. The process of claim 7, wherein programming the first memory cell further comprises:

placing the first gate electrode at a first substantially constant potential; and

placing the third gate electrode at a second substantially constant potential that is different from the first substantially constant potential.