2023 AIChE Annual Meeting
Optimizing Spin Coating Parameters for Uniform Photoresist Deposition on Silicon Wafers in Diffraction Grating Development
This poster presents a study focused on achieving uniform deposition of photoresist on silicon wafers for use in diffraction grating development. Spin coating, a common technique for thin-layer deposition, was utilized to achieve uniform photoresist layers on the wafers. Through a comprehensive Design-of-Experiments (DOE) approach, various spin coating parameters were systematically examined to enhance the deposition process. The variables explored included spin speed, spin time, ramp speed, ramp steps, exhaust percentage, wafer bake time, and use of a primer agent. These elements offer insights into the factors governing uniform photoresist deposition on silicon and fused silica substrates. It was observed that shorter bake times, lower exhaust percentages, and slower ramp speeds resulted in the desired photoresist layer of 800 to 1000 nanometers. In addition, a sufficiently large first ramp step in the spin-up process resulted in more uniformity of deposition. The resulting coated wafers from this process are later used in photolithography and reactive ion etching processes to improve the manufacturing process for optical diffraction gratings.