Submicron connection layer and method for using the same to connect wafers

Abstract

A submicron connection layer and a method for using the same to connect wafers is disclosed. The connection layer comprises a bottom metal layer formed on a connection surface of a wafer, an intermediary diffusion-buffer metal layer formed on the bottom metal layer, and a top metal layer formed on the intermediary diffusion-buffer metal layer. The melting point of the intermediary diffusion-buffer metal layer is higher bottom metal layers may form a eutectic phase. During bonding wafers, two top metal layers are joined in a liquid state; next the intermediary diffusion-buffer metal layers are distributed uniformly in the molten top metal layers; then the top and bottom metal layers diffuse to each other to form a low-resistivity eutectic intermetallic compound until the top metal layers are completely exhausted by the bottom metal layers.