Effects of bonding process parameters on wafer-to-wafer alignment accuracy in benzocyclobutene (BCB) dielectric wafer bonding
2005 (English)In: Materials, Technology and Reliability of Advanced Interconnects-2005 / [ed] Besser PR; McKerrow AJ; Iacopi F; Wong CP; Vlassak JJ, WARRENDALE, PA: MATERIALS RESEARCH SOCIETY , 2005, Vol. 863, 393-398 p.Conference paper (Refereed)
Wafer-level three-dimensional (3D) integration is an emerging technology to increase the performance and functionality of integrated circuits (ICs). Aligned wafer-to-wafer bonding with dielectric polymer layers (e.g., benzocyclobutene (BCB)) is a promising approach for manufacturing of 3D ICs, with minimum bonding impact on the wafer-to-wafer alignment accuracy essential. In this paper we investigate the effects of thermal and mechanical bonding parameters on the achievable post-bonding wafer-to-wafer alignment accuracy for polymer wafer bonding with 200 trim diameter wafers. Our baseline wafer bonding process with soft-baked BCB (similar to 35% cross-linked) has been modified to use partially cured (similar to 43% crosslinked) BCB. The partially cured BCB layer does not reflow during bonding, minimizing the impact of inhomogeneities in BCB reflow under compression and/or slight shear forces at the bonding interface. As a result, the non-uniformity of the BCB layer thickness after wafer bonding is less than 0.5% of the nominal layer thickness and the wafer shift relative to each other during the wafer bonding process is less than 1 mu m (average) for 200 mm diameter wafers. The critical adhesion energy of a bonded wafer pair with the partially cured BCB wafer bonding process is similar to that with soft-baked BCB.
Place, publisher, year, edition, pages
WARRENDALE, PA: MATERIALS RESEARCH SOCIETY , 2005. Vol. 863, 393-398 p.
, MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS, ISSN 0272-9172 ; 863
IdentifiersURN: urn:nbn:se:kth:diva-24815ISI: 000232485800061ISBN: 1-55899-816-0OAI: oai:DiVA.org:kth-24815DiVA: diva2:353432
Symposium on Materials, Technology and Reliability of Advanced Interconnects held at the 2005 MRS Spring Meeting San Francisco, CA, MAR 28-APR 01, 2005
QC 201009272010-09-272010-09-272010-09-27Bibliographically approved