Method of manufacturing a twin well semiconductor device with improved planarity

摘要

A method for manufacturing semiconductor devices having a twin well structure in which the N-well and P-well regions of the substrate receive differential processing to set the final planarity of the semiconductor device. The differential processing permits the relative vertical position of the N-well and P-well surfaces to be controlled as needed to reduce the demands on subsequent processing steps. The relative vertical position of the N-well and P-well surfaces are preferentially set to improve the planarity of the semiconductor device during subsequent manufacturing processes, particularly photolithographic and metallization processes.