Advantages of Thermal Nitride and Nitroxide Gate Films in VLSI Process

Thin gate SiO/sub 2/ films thinner than 200 /spl Aring/ often deteriorate throughout developmentaf VLSI processes, including refractory metal or silicide gates and ion- or plasma-assisted processes. Thermal nitridation of such SiO/sub 2/ films improves the MOS characteristics by producing surface protective layers against impurity penetration and by producing good interfacial characteristics. This fact indicates that a thermally grown silicon nitride film on a silicon substrate is the most promising candidate for a very-thin gate insulator. Experimental data show significant benefits from the nitride film for future VLSI devices.