BCB-to-oxide bonding technology for 3D integration

Abstract

Process optimization of BCB polymer to silicon oxide bonding was investigated. The suitable bonding temperature is about 300 degrees C, while bond failure of BCB-to-oxide bonding is observed starting from 400 degrees C. Bonding interface morphologies and bond strengths of BCB-to-oxide bonding were investigated as well. PECVD oxide to BCB bonding has better bonding quality than that of thermal oxide to BCB bonding. Si-O-Si bonds may be the reason of a strong BCB to oxide bonding. Water molecules link BCB and oxide surfaces during the initial contact, while Si-O-Si bonds are formed during bonding. This proposed mechanism of BCB-to-oxide bonding provides a guideline for polymer to oxide hybrid bonding technology in 3D integration. (C) 2011 Elsevier Ltd. All rights reserved.