STI LINER MODIFICATION METHOD

摘要

A new and improved liner modification method for a liner oxide layer in an STI trench is disclosed. According to the method, an STI trench is etched in a substrate and a liner oxide layer is formed on the trench surfaces by oxidation techniques. The method further includes pre-treatment of the trench surfaces using a nitrogen-containing gas prior to formation of the liner oxide layer, post-formation nitridation of the liner oxide layer, or both pre-treatment of the trench surfaces and post-formation nitridation of the liner oxide layer. The liner modification method of the present invention optimizes the inverse narrow width effect (INWE) and gate oxide integrity (GOI) of STI structures and prevents diffusion of dopant into the liner oxide layer during subsequent processing.