Thermal Stability of Self-Assembled 3-Aminopropyltrimethoxysilane Diffusion Barrier Terminated by Carboxyl Groups

Abstract

The carboxyl-terminated 3-aminopropyltrimethoxysilane (APTMS) self-assembled monolayer (SAM) diffusion barrier was prepared onto a Si substrate via molecular self-assembly and graft modification technology. The SAM was afterward coated with a copper film via radio-frequency (RF) magnetron sputtering. In order to study the thermal stability of the diffusion barrier, the sample was subsequently annealed for 60 min in an Ar environment at the temperatures of 350 °C, 400 °C, 450 °C, 500 °C, and 550 °C. The results revealed that carboxyl modification enabled one to increase the barrier breakdown temperature of the APTMS diffusion barrier layer by about 100 °C, which was sufficient to effectively inhibit the copper diffusion at 500 °C.