This paper will demonstrate both line/space and contact hole Critical Dimension Uniformity (CDU), one of the key indicators of resolution performance, as well as process window performance on multiple masks and resist processes. The CDU performance shows significant improvement after three main factors were implemented: custom-made photoresist, track process optimization, and Nikon Turnkey CDU Master software application. It will be demonstrated that with the implementation of optimized photoresist, Post Exposure bake (PEB) tuning and CDU Master correction that CDU results of <1nm 3σ may be achieved on 450mm wafers. The final CDU results for contact hole and line/space will be compared to 300mm production tools as well as the N7 and N10 expected requirements.
Besides a traditional 6% Attenuated Phase Shifting Mask (APSM), G450C litho also utilizes thin Opaque MoSi On Glass Mask (OMOG). Process window comparisons will be evaluated on both mask technologies for all of the resist processes. In addition to the test masks, G450C completed the design of a three layer mask set with resist based Optical Proximity Correction (OPC) modeling and gathered “on product” CDU performance on a Back End Of Line (BEOL) metal stack.