POLYSILICON GATE REOXIDATION IN A GAS MIXTURE OF OXYGEN AND NITROGEN TRIFLUORIDE GAS BY RAPID THERMAL PROCESSING TO IMPROVE HOT CARRIER IMMUNITY AND DEVICE PRODUCED THEREBY

摘要

A method of forming an FET transistor comprises forminga stack of a gate oxide layer and a control gate electrodeon a surface of a doped semiconductor substrate withcounterdoped source/drain regions therein. A silicon oxidelayer is formed over the stack of the gate oxide layer andthe control gate electrode and exposed portions of thesemiconductor substrate including the source/drain regions.Then the silicon oxide layer and the corners of the gateoxide layer are fluorinated by rapid thermal processingproviding a fluorinated silicon oxide layer. The rapidthermal processing is performed in an atmosphere of NF3 gasand 0[err] gas at a temperature from about 900[err]C to about 1050[err]Cfor a time duration from about 10 seconds to about 50 sec-onds, and the fluorinated silicon oxide layer has a thick-ness from about 200A to about 400A.