Browse Prior Art Database

Single Mask and Imaging for a Dual Level Self Aligned Definition

IP.com Disclosure Number: IPCOM000040649D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 98K

Publishing Venue

IBM

Related People

Cronin, JE: AUTHOR

Abstract

A novel semiconductor fabrication process sequence is reported to form interlevel metal via interconnections, self aligned to the bottom metal, without a via mask. A problem of chemical vapor deposition (CVD) metals not filling varying size holes is also a useful tool in the fabrication of self aligned metal lines to interlevel via contacts or studs and eliminates a mask step. By designing M1 lines to bloom wherever an interlevel via is required, as shown in Fig. 1 (top view), a self aligned via can be fabricated without an additional mask step. Initially, a first level metal (M1) is defined by utilizing a reactive ion etch (RIE) through a thick mask material, as shown in the cross-section. Next, a CVD oxide is deposited and planarized, as shown in Fig. 2.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Single Mask and Imaging for a Dual Level Self Aligned Definition

A novel semiconductor fabrication process sequence is reported to form interlevel metal via interconnections, self aligned to the bottom metal, without a via mask. A problem of chemical vapor deposition (CVD) metals not filling varying size holes is also a useful tool in the fabrication of self aligned metal lines to interlevel via contacts or studs and eliminates a mask step. By designing M1 lines to bloom wherever an interlevel via is required, as shown in Fig. 1 (top view), a self aligned via can be fabricated without an additional mask step. Initially, a first level metal (M1) is defined by utilizing a reactive ion etch (RIE) through a thick mask material, as shown in the cross-section. Next, a CVD oxide is deposited and planarized, as shown in Fig. 2. The RIE mask is chemically removed, and the oxide is left intact, as shown in Fig. 3. A CVD oxide is deposited to a thickness such that only the hole over the metal line is filled, as shown in Fig. 4. The metal pad has spacers formed on the sidewalls and an etchback is performed to expose metal in the pad area. A conformal metal is deposited to fill the vertical self aligned contact hole (not shown) to form an interconnect via stud.

1

Page 2 of 2

2

[This page contains 4 pictures or other non-text objects]