Reduction of hot-carrier generation in 0.1-μm recessed channel nMOSFET with laterally graded channel doping profile

To investigate the substrate current characteristics of a recessed channel structure with graded channel doping profile, we have fabricated and simulated the Inverted-Sidewall Recessed-Channel (ISRC) nMOSFET and compared it with a conventional planar nMOSFET. Experimentally, the ISRC nMOSFET shows about 30% reduction of substrate current, even though the drain current is almost the same. At 0.12-μm channel length, the I/sub SUB//I/sub DS/ value of the conventional nMOSFET is measured to be 1.68 times higher than that of the ISRC nMOSFET. Also, using simulation, it is verified that the reduction of electric field at the drain junction of ISRC nMOSFET results from the graded channel doping profile, not from the recessed channel structure.