High step process for manufacturing alignment marks for twin-wel

Details High step process for manufacturing alignment marks for twin-wel High step process for manufacturing alignment marks for twin-wel

1996-11-01

1998-09-29

Bowers, Jr., Charles L.

Semiconductor device manufacturing: process

Coating with electrically or thermally conductive material

438584, 438401, 438975, 438694, 438703, 430 22, 430312, 148DIG102, 148DIG70, H01L 2700, H01L 27265

Patent

active

058145524

ABSTRACT:
A method of fabricating high step alignment marks on a twin-well integrated circuit. An alignment mark photoresist pattern is formed overlaying the nitride layer using lithography technique. The nitride layer is partially etched to form a nitride alignment pattern using the alignment mark photoresist pattern as a mask. After the formation of N-well and P-well regions using lithography technique, the N-doped and P-doped impurities are subject to a thermally drive in process to activate and form N-well and P-well regions, respectively. At the same time, the pad oxide layer overlaying the N-well and P-well regions and the region not covered by the nitride alignment pattern is converted to a thermal oxide layer. The thermal oxide layer can be removed to reveal a recessed portion on the surface of the P-type silicon substrate, whereby the thickness of the nitride layer plus the depth of the recessed portion causes high step alignment marks to be formed.

REFERENCES:
patent: 4938841 (1990-07-01), Shahar et al.
patent: 5002902 (1991-03-01), Watanabe
patent: 5091332 (1992-02-01), Bohr et al.
patent: 5132241 (1992-07-01), Su
patent: 5252510 (1993-10-01), Lee et al.
patent: 5300797 (1994-04-01), Bryant et al.
patent: 5406373 (1995-04-01), Kamon
patent: 5679588 (1997-10-01), Choi et al.
Wolf et al., Silicon Processing for The VLSI Era, vol. 2, pp. 428-431, 1986.
S. Wolf. Silicon Processing for the VLSI Era, vol. 2: Process Integration, p. 431, 1990.

Affiliated with

Also associated with

Rating

High step process for manufacturing alignment marks for twin-wel does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High step process for manufacturing alignment marks for twin-wel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High step process for manufacturing alignment marks for twin-wel will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-685914