Reducing Fluorocarbon Usage in SiNx Etch Process

This technical report investigates a legacy fluorocarbon-based silicon nitride (SiNx) etch process used for resistor layers. The primary objective is to reduce the global warming potential (GWP) associated with the etching process while maintaining or improving productivity and cost-effectiveness. The study reveals that by eliminating the use of CHF3, a polymerizing gas, the etch rate can be significantly increased, and the process time can be halved without adversely affecting the device performance. Experimental results indicate that critical dimensions and electrical characteristics of the resistors produced are consistent and meet specification requirements. The report outlines the experimental procedures, including the characterization methods employed to assess the etching process, and concludes that it is feasible to achieve sustainability goals alongside productivity improvements. This work contributes to the semiconductor industry's efforts to minimize greenhouse gas emissions while maintaining manufacturing efficiency.