Identification and Characterization of a Subtle Bump Defect Formed Upon Organic Mandrel in a Self-Aligned Double Patterning Process

Core bump defect is yield killer in terms of causing blocked etch during poly-Si hard mask etching in the spacer-type self-aligned double patterning (SADP) manufacture process flow. By clarifying the characteristics and formation mechanism of the core bump defect occurred on the top of the organic mandrel post room temperature oxide deposition, several strategies, e.g., electron beam illumination, high/low pressure baking and pulsed plasma etch, were explored. Afterward an effective suppression of the core bump adder was developed, resulting in the sorting yield ramping up by 10% at least.