CMP compatibility of partially cured benzocyclobutene (BCB) for a via-first 3D IC process
2005 (English)In: Chemical-Mechanical Planarization-Integration, Technology and Reliability / [ed] Kumar A; Lee JA; Obeng YS; Vos I; Johns EC, WARRENDALE, PA: MATERIALS RESEARCH SOCIETY , 2005, Vol. 867, 63-68 p.Conference paper (Refereed)
Wafer-level three dimensional (3D) IC technology offers the promise of decreasing RC delays by reducing long interconnect lines in high performance ICs. This paper focuses on a via-first 3D IC platform, which utilizes a back-end-of-line (BEOL) compatible damascene-patterned layer of copper and Benzocyclobutene (BCB). This damascene-patterned copper/BCB serves as a redistribution layer between two fully fabricated wafer sets of ICs and offers the potential of high bonding strength and low contact resistance for inter-wafer interconnects between the wafer pair. The process would thus combine the electrical advantages of 3D technology using Cu-to-Cu bonding with the mechanical advantages of 3D technology using BCB-to-BCB bonding. In this work, partially cured BCB has been evaluated for copper damascene patterning using commercially available CMP slurries as a key process step for a via-first 3D process flow. BCB is spin-cast on 200 mm wafers and cured at temperatures ranging from 190 degrees C to 250 degrees C, providing a wide range of crosslink percentage. These films are evaluated for CMP removal rate, surface damage (surface scratching and embedded abrasives), and planarity with commercially available copper CMP slurries. Under baseline process parameters, erosion, and roughness changes are presented for single-level damascene test patterns. After wafers are bonded under controlled temperature and pressure, the bonding interface is inspected optically using glass-to-silicon bonded wafers, and the bond strength is evaluated by a razor blade test.
Place, publisher, year, edition, pages
WARRENDALE, PA: MATERIALS RESEARCH SOCIETY , 2005. Vol. 867, 63-68 p.
, MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS, ISSN 0272-9172 ; 867
IdentifiersURN: urn:nbn:se:kth:diva-24814ISI: 000231387500010ISBN: 1-55899-820-9OAI: oai:DiVA.org:kth-24814DiVA: diva2:353471
Symposium on Chemical-Mechanical Planarization held at the 2005 MRS Spring Meeting San Francisco, CA, MAR 28-31, 2005
QC 201009272010-09-272010-09-272010-09-27Bibliographically approved