Improving Gate Oxide Uniformity Using Wet-Dry Oxidation for Semiconductor Manufacturing

The uniformity of gate oxide is essential to the semiconductor manufacturing process. An unsatisfactory uniformity can lead to a decrease in device performance and yield. This work studies the uniformity of gate oxide film formed in three ways, including dry oxidation, wet oxidation and a sequential process of wet oxidation followed by dry oxidation (wet-dry). The uniformity of gate oxide film decreases as temperature rises between 750 ~ 900°C, and as the gas flow increases. The wet-dry process can maintain a high uniformity at relatively high thickness compared to wet and dry processes. This work will be beneficial to achieving the ideal process window for the target gate oxide film.