Wet etch process and methods to form air gaps between metal interconnects

Abstract

Embodiments of improved process flows and methods are provided in the present disclosure to form air gaps between metal interconnects. More specifically, the present disclosure provides improved process flows and methods that utilize a wet etch process to form recesses between metal interconnects formed on a patterned substrate. Unlike conventional air gap integration methods, the improved process flows and methods described herein utilize the critical dimension (CD) dependent etching provided by wet etch processes to etch an intermetal dielectric material formed between the metal interconnects at a faster rate than the intermetal dielectric material is etched in surrounding areas of the patterned substrate. This enables the improved process flows and methods described herein to form recesses (and subsequently form air gaps) between the metal interconnects without using a dry etch process.