Mixed Orientation Si-Si Interfaces by Hydrophilic Bonding and High Temperature Oxide Dissolution: Wafer Fabrication Technique and Device Applications

Abstract

In this paper we describe a quasi-hydrophobic bonding method in which ultrathin (<1-2 nm) oxide present on wafer surfaces during bonding is removed after bonding by a high-temperature oxide dissolution anneal to leave the desired direct Si-to-Si contact at the bonded interface. We will show that the direct- silicon-bonded (DSB) interfaces produced by this method are clean enough to allow implementation of a recently described amorphization/templated recrystallization technique for changing the orientation of selected DSB layer regions from their original orientation to the orientation of the underlying handle wafer, and then discuss some of the mechanisms and integration challenges associated with wafer and device fabrication by these techniques.