Photoresist ashing in nitrogen gas using ferrite core inductively coupled plasmas

The characteristics of photoresist (PR) ashing using N2 plasmas in a ferrite core inductively coupled plasma etcher have been studied and the effect of bias power and gas flow rate on PR ash rate and low-k material etch rate has been investigated. Fourier transform infrared spectroscopy revealed that the ashing process with N2 gas produced less damage to the low-k material compared to the process with O2 gas. The HF etch test was used to evaluate the ash damage to the low-k material.