MOSFET AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a MOSFET(metal oxide semiconductor field effect transistor) and a method for manufacturing the MOSFET capable of eliminating the overlap of a gate dielectric and a source/drain region with high reliability. SOLUTION: This method for manufacturing a MOSFET comprises the process of patterning a gate laminate constituted of a gate dielectric 20 arid a gate conductor 30 formed on a substrate 10, and the process of modifying the gate dielectric 20 beneath the gate dielectric 30 so that the gate dielectric 20 can have a central portion and a modified dielectric region 70 adjacent to the central portion. The modified dielectric region 70 has a lower dielectric constant than that of the gate dielectric 20, and the central portion is shorter than the gate conductor 30.