Browse Prior Art Database

Process for Multilayer Metal Technology

IP.com Disclosure Number: IPCOM000045460D
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Chiu, GT: AUTHOR [+4]

Abstract

Fig. 1 describes a prior via- and metal-forming process in this technology. Fig. 2 is an improved via process incorporated in which no trench around via stud will be formed due to over RIE (reactive ion etch) during M level L/O (lift-off) RIE because of a true RIE etchstop around the via studs.

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Process for Multilayer Metal Technology

Fig. 1 describes a prior via- and metal-forming process in this technology. Fig. 2 is an improved via process incorporated in which no trench around via stud will be formed due to over RIE (reactive ion etch) during M level L/O (lift-off) RIE because of a true RIE etchstop around the via studs.

As can be seen in Fig. 2, the M metal formed as such has only a minor step at edge of SiN(x) openings which can be as small as 3000 Angstroms or less. In the case of Fig. 1, that step or gap can be as deep as 10,000 Angstroms in some cases due to over RIE to take care of topology differences, causing M metal opens (breaks)

Fig. 2 shows good alignment to L studs. In case of misalignment, only one side of the via has a gap and the other side still gives good continuity of M metal; thus the chances of metal being open are cut down to half. By opening the SiN(x) with separate photoresist (P/R) masking, one can produce a trench-free multilayer metal (MLM) personalization which is more forgiving and evidently will give higher yield.

It also has only one set of RIE parameters for both metal and via lift-off RIE.

There is no need to etch (RIE) SiN(x) in the L/O RIE process, which is a lot easier than prior technology.

Naturally, this process is extendable to all levels of MLM technology, not restricted to M and L only.

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