High fidelity multiple resist patterning

A method of processing a semiconductor wafer, the method comprising:

• creating, from a first photoresist material, a first pattern of photoresist features over a target material of the semiconductor wafer;
• applying a second photoresist material over the target material and over the first pattern of photoresist features;
• heating the second photoresist material at a bake temperature to soften the second photoresist material while preserving the first pattern of photoresist material, resulting in a substantially planarized exposed surface of the second photoresist material;
• exposing the second photoresist material with patterned radiation, resulting in an exposed second photoresist layer;
• and
• developing the exposed second photoresist layer into a second pattern of photoresist features, where the first pattern of photoresist features and the second pattern of photoresist features form an overall photoresist pattern for the semiconductor wafer.

A method of processing a semiconductor wafer, the method comprising:

• creating, from a first photoresist material, a first pattern of photoresist features over a target material of the semiconductor wafer;
• applying a second photoresist material over the target material and over the first pattern of photoresist features;
• exposing the second photoresist material to a solvent to soften the second photoresist material while preserving the first pattern of photoresist material, resulting in a substantially planarized exposed surface of the second photoresist material;
• exposing the second photoresist material with patterned radiation, resulting in an exposed second photoresist layer;
• and
• developing the exposed second photoresist layer into a second pattern of photoresist features, where the first pattern of photoresist features and the second pattern of photoresist features form an overall photoresist pattern for the semiconductor wafer.