An Efficient Method of Wafer Thermal Uniformity Improvement and Wafer Edge Yield Enhancement by Utilizing Backside Film Removing

The wafer non-uniformity of WAT and yield within wafer (WIW) and wafer to wafer (WTW) is a major and everlasting problem, which is mainly caused by rapid thermal process and Spacer-2 Nitride deposition process. In this paper, we develop a simple method to remove nitride film on wafer backside with H3PO4treatment while protecting wafer front pattern completely by utilizing two different films. The excellent uniformity WIW and WTW can be acquired by utilizing this method, which is extremely promising for wafer thermal uniformity improvement and wafer edge yield enhancement.