Method to detect poly residues in LOCOS process

摘要

A test structure which can be used to detect residual conductive material such as polysilicon which can result from an under etch comprises a PMOS transistor and an OTP EPROM floating gate device. By testing the devices using different testing parameters, it can be determined whether residual conductive material remains subsequent to an etch, and where the residual conductive material is located on the device. A method for testing a semiconductor device using the test structure is also described.