Method of making a contact and via structure

Details Method of making a contact and via structure Method of making a contact and via structure

2001-08-24

2003-03-18

Niebling, John F. (Department: 2812)

Semiconductor device manufacturing: process

Coating with electrically or thermally conductive material

To form ohmic contact to semiconductive material

C438S625000, C438S669000, C438S687000, C438S688000

Reexamination Certificate

active

06534403

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of semiconductor processing and more specifically to novel contact and via structures and their method of fabrication.
2. Discussion of Related Art
Modern integrated circuits and memory devices include multiple levels of metalization separated by insulating layers. The normal method of making contact from one metalization layer to another is to use photoresist as a mask and to dry etch the insulators stopping on the underlying conductor. Once an opening is formed this way, then the opening is filled with a second deposited conductor. Today the conductor is usually chemical vapor deposited (CVD) tungsten because the sidewall slopes are too steep for a sputtered metal to cover. Historically, people use trick etches of the insulator to provide a slope on the sidewalls so that the sputter metals could cover the sidewall and therefore not need CVD metal deposition. It is to be appreciated that presently low resistance metals such as aluminum is typically be deposited by sputtering and not by CVD. Today, however, people have gone away from slope sidewalls because the process is hard to control and because the area required to make the contact is too large.
SUMMARY OF THE INVENTION
The present invention is a contact/via and its method of fabrication. The contact/via of the present invention is formed on a first conductive film. The contact has a first sidewall and a second sidewall wherein the first sidewall is opposite the second sidewall. The first sidewall has a stair step configuration such that the first sidewall is closer to the second sidewall at the bottom of the contact than at the top of the contact. A second conductive film is formed on the stair step sidewall on the conductive film.


REFERENCES:
patent: 4840923 (1989-06-01), Flagello et al.
patent: 4922320 (1990-05-01), McDavid et al.
patent: 5227013 (1993-07-01), Kumar
patent: 5550404 (1996-08-01), Yen et al.
patent: 5734200 (1998-03-01), Hsue et al.
patent: 5745407 (1998-04-01), Levy et al.
patent: 5910020 (1999-06-01), Yamada
patent: 5917229 (1999-06-01), Nathan et al.
patent: 6031257 (2000-02-01), Noto et al.
patent: 6040604 (2000-03-01), Lauvray et al.
patent: 6093963 (2000-07-01), Chan et al.
patent: 6303877 (2001-10-01), Moriizumi et al.
“Exotic Memories, Diverse Approaches”EDN Asia Magazine, Sep. 2001.
International Search Report PCT/US 01/29150.

Affiliated with

Also associated with

Rating

Method of making a contact and via structure does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of making a contact and via structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of making a contact and via structure will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3042838