The behavior of substrate dependency as surface treatment in the positive chemically amplified resist

Positive chemically amplified resist (CAR) is widely used because of its benefit to high resolution in the semiconductor industry. Recent numerous studies have reported that resist pattern error such as resist scum and adhesion fail at the interface between substrate and positive CAR is caused by substrate dependency. Hence resist pattern error must be minimized. In this study we have observed the phenomena at the positive CAR coated mask blanks. And then we applied various surface treatments to the Cr film to minimize resist pattern error. Firstly, resist pattern error was occurred by the substrate dependency in the positive CAR coated mask blanks. We have investigated the root causes of this pattern error, we found that nitrogen radical and OH radical in the Cr film could combine with proton in the positive CAR easily. So various surface treatments were applied to minimize detrimental effects of substrate dependency to the positive CAR. And the behavior of substrate dependency was observed by various analyses to verify the effect of surface treatment method. The results showed that substrate dependency could be controlled by surface treatment in the positive CAR coated mask blanks.