Method of wafer bonding of dissimilar thickness die

Abstract

Methods, assemblies, and equipment are described for bonding one or more die that may be of dissimilar thickness to a wafer. The die may be fabricated and singulated with a planarized oxide layer protecting from wafer dicing and handling debris one or more metallized post structures connecting to an integrated circuit. Face sides of the die are bonded to a first handle wafer, such that the respective post structures are aligned in a common plane. The substrate material back sides of the bonded die are then thinned to a uniform thickness and bonded to a second handle wafer. The assembly may then be flipped, and the first handle wafer and protective layer including potential dicing and handling debris removed. The post structures are revealed, resulting in a composite wafer assembly including the second handle and one or more uniformly thinned die mounted thereto.