This novel process was useful not only in positive tone development (PTD) process but also in negative tone development (NTD) process. We newly developed DDRM for NTD process. Novel DDRM consist of special polymer and it used organic solvent system. So, new DDRM showed no mixing property with NTD photo resist and it has enough etch selectivity against NTD photo resist.
Image reversal was successfully achieved by combination of NTD process and DDR process keeping good pattern quality. Tone reverse pattern below hp 18nm was obtained without any pattern collapse issue, which couldn’t be created by just using normal NTD process.