Method for pattern reduction using a staircase spacer

Devices are made by self-aligned quad pitch patterning (SAQP), staircase patterning and double staircase patterning. Methods for making devices by self-aligned quad pitch patterning (SAQP) use a single spacer in the process. Methods for making devices by staircase patterning and double staircase patterning do not use a spacer. An intermediate process step called self-aligned double patterning (SADP) is used to double the pitch following the spacer deposition. A pattern is formed on a substrate, the pattern having ultra-fine resolutions by repeating the SADP step twice for pitch quadrupling and introducing a reversal layer to form a fine trench pattern and hole pattern. The pattern designs or pattern layouts have improved LER/LWR (line edge roughness and line width roughness respectively) for below 12 nm lines and trenches in order to create self-aligned cross pitch quad trenches.