Mo2N/Mo gate MOSFETs

Molybdenum nitride coatings on molybdenum using a direct reaction of molybdenum with ammonia is used to improve the gate electrode properties of Mo gate self-aligned MOSFETs. The Mo2N double layer gate shows resistance against oxidation, processing reagents and improved ion implantation masking. The work function of the double layer film was determined to be 4.69 ± 0.03 eV which is independent of the nitride thickness and annealing conditions. Boron implantation range is smaller in Mo2N than Mo. A Mo2N coating of 870Å over 2130Å Mo masks up to 60 keV B11 and 120 keV As75. The implantation study covers the energy range from 15 to 70 keV for boron and from 40 to 160 keV for arsenic.