Browse Prior Art Database

Refractory Contact Stud

IP.com Disclosure Number: IPCOM000039156D
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Huang, HW: AUTHOR

Abstract

Disclosed is a method of forming a planarized multilevel metal contact stud structure using refractory metals, such as W. A TiW-Al-W stud, in place of conventional TiW-Al stud prior to planarization, minimizes metal penetration which may occur at contacts. In the process, metals are sputter-deposited successively on the PtSi or Si chip contact 1 (Fig. 1). The sequence followed would be deposition of TiW 2, Al 3, W 4, and Al 5, upon which photoresist (PR) 6 would be applied. The PR serves as a mask for etching the top Al 5 layer. The Al 5 layer serves as a mask for etching the W 4 layer, while the Al 3 layer serves as an etching stop. A series of etching steps are undertaken to achieve the structure shown in Fig. 2, wherein W 4, Al 3, and TiW 2 are the metals remaining above the chip contact 1.

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Refractory Contact Stud

Disclosed is a method of forming a planarized multilevel metal contact stud structure using refractory metals, such as W. A TiW-Al-W stud, in place of conventional TiW-Al stud prior to planarization, minimizes metal penetration which may occur at contacts. In the process, metals are sputter-deposited successively on the PtSi or Si chip contact 1 (Fig. 1). The sequence followed would be deposition of TiW 2, Al 3, W 4, and Al 5, upon which photoresist (PR) 6 would be applied. The PR serves as a mask for etching the top Al 5 layer. The Al 5 layer serves as a mask for etching the W 4 layer, while the Al 3 layer serves as an etching stop. A series of etching steps are undertaken to achieve the structure shown in Fig. 2, wherein W 4, Al 3, and TiW 2 are the metals remaining above the chip contact 1. A planarization step is next used to complete the structure as shown in Fig. 3. Plasma-enhanced chemical vapor deposited Si3N4 7 is deposited, followed by a deposition of quartz 8, followed by planarization. The proposal is simpler than other processes, can be effected with tight ground rules, and has improved reliability with respect to electromigration and metal penetration.

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