Process for producing two bit ROM cell utilizing angled implant

Semiconductor device manufacturing: process – Making field effect device having pair of active regions... – Having insulated gate

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

438275, 438276, 438291, 438525, H01L 218236

Patent

active

060308710

ABSTRACT:
A dual bit read only memory cell has two bits separately stored in two different areas of the channel, such as the left and right bit line junctions of the channel. A programmed bit has a threshold pocket implant self-aligned to its bit line junction and an unprogrammed bit has no such implant. An array of such cells is manufactured by laying down a bit line mask and separately programming the two bit line junctions. For each bit line junction, the bit line junctions which are to remain unprogrammed are first covered, with a junction mask, after which the array is exposed to a threshold pocket implant at a 15-45.degree. angle, to the right or to the left. The junction mask is removed and the process repeated for the other bit line junction. Finally, the bit line mask is removed. In an alternative embodiment, the threshold pocket implant is two implants, of two different materials.

REFERENCES:
patent: 4173766 (1979-11-01), Hayes
patent: 4173791 (1979-11-01), Bell
patent: 4527257 (1985-07-01), Cricchi
patent: 4630085 (1986-12-01), Koyama
patent: 4847808 (1989-07-01), Kobatake
patent: 5021999 (1991-06-01), Kohda et al.
patent: 5168334 (1992-12-01), Mitchell et al.
patent: 5204835 (1993-04-01), Eitan
patent: 5214303 (1993-05-01), Aoki
patent: 5349221 (1994-09-01), Shimoji
patent: 5359554 (1994-10-01), Odake et al.
patent: 5412601 (1995-05-01), Sawada et al.
patent: 5414693 (1995-05-01), Ma et al.
patent: 5418743 (1995-05-01), Tomioka et al.
patent: 5424978 (1995-06-01), Wada et al.
patent: 5426605 (1995-06-01), Van Berkel et al.
patent: 5434825 (1995-07-01), Harari
patent: 5768192 (1998-06-01), Eitan
patent: 5825686 (1998-10-01), Schmitt-Lansiedel et al.
T.Y. Chan et al.; "A True Single-Transistor Oxide-Nitride-Oxide EEPROM Device"; IEEE Electron Device Letters, vol. Edl-8, No. 3, Mar. 1987 pp. 93-95.
Eitan et al.; "Hot-Electron Injection into the Oxide in n-channel MOS Devices"; IEEE Transactions on Electron Devices, vol. ED-38, No. 3, Mar. 1981 328-340.
Lance A. Glasser et al., The Design and Analysis of VLSI Circuits, Addison-Wesley Publishing Company, Jul. 1988, Chapter 2., pp. 67-163.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process for producing two bit ROM cell utilizing angled implant does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for producing two bit ROM cell utilizing angled implant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing two bit ROM cell utilizing angled implant will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-682422

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.