Strategy for line width roughness (LWR) reduction in carbon mandrel patterning

Multi-patterning has been widely used in the semiconductor manufacturing industry to get narrow pitch at beyond 40nm technology node. Self-aligned double patterning (SADP) with a carbon pattern as the first mandrel shows significant process to meet the patterning pitch line/space features. The requirements for the Line Width Roughness (LWR) of mandrel reformation etch is extremely strict. This paper focuses on LWR reduction in carbon mandrel patterning etch. The effects of HBr curing organic mask and $\mathrm{C}_{\mathrm{X}} \mathrm{H}_{\mathrm{Y}} \mathrm{F}_{\mathrm{Z}}$ deposition are investigated. LWR is optimized with HBR curing and $\mathrm{C}_{\mathrm{X}} \mathrm{H}_{\mathrm{Y}} \mathrm{F}_{\mathrm{Z}}$ deposition.