RRC (Reducing Resist Consumption) process is widely used in the Semiconductor industry to decrease the cost of photo resist per wafer. However, the process is often accompanied with various coating defects that make it difficult to improve final yield and further reduce resist cost per wafer. Deep ultraviolet (DUV) bottom anti-reflective coating is critical to critical dimension (CD) control and is used for most critical layers like Poly, STI and Contact layers. This paper will present a novel double pre-wet RRC process to reduce both coating defects and resist consumption of BARC. The relationship between resist consumption per coating and thickness uniformity (mean and range) of the new process was evaluated. The stability test results of the new process shows acceptable manufacturing results. Coating defects from double pre-wet RRC process were analyzed and compared with the normal coating process without RRC. The effect of DUV BARC coating performed by the double pre-wet RRC process on critical dimension (CD) performance of Island, Poly and Contact layer was also reported.
