SUBSTRATE BONDING WITH DIFFUSION BARRIER STRUCTURES

摘要

A metallic dopant element having a greater oxygen-affinity than copper is introduced into, and/or over, surface portions of copper-based metal pads and/or surfaces of a dielectric material layer embedding the copper-based metal pads in each of two substrates to be subsequently bonded. A dopant-metal silicate layer may be formed at the interface between the two substrates to contact portions of metal pads not in contact with a surface of another metal pad, thereby functioning as an oxygen barrier layer, and optionally as an adhesion material layer. A dopant metal rich portion may be formed in peripheral portions of the metal pads in contact with the dopant-metal silicate layer. A dopant-metal oxide portion may be formed in peripheral portions of the metal pads that are not in contact with a dopant-metal silicate layer.

主权项

1. A bonded structure comprising a vertical stack of a first substrate and a second substrate, wherein said first substrate includes a first silicon oxide layer embedding first metal pads predominantly including copper and said second substrate includes a second silicon oxide layer embedding second metal pads predominantly including copper,
wherein horizontal surfaces of said first metal pads are bonded to surfaces of said second metal pads at a plane of an interface, and wherein a metal silicate material is in physical contact with a peripheral portion of a surface of one of said first and second metal pads at said plane of said interface and adjoined to at least one of said first and second silicon oxide layers.