Mo2N/Mo gate MOSFET´s

Molybdenum nitride coatings on molybdenum, from a direct reaction of molybdenum with ammonia, are used to improve the gate electrode properties of Mo gate self-aligned MOSFET´s. A Mo2N double-layer gate shows resistance against oxidation and 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. The projected range of boron implantation is smaller in Mo2N than in Mo. A Mo2N coating of 870 Å over 2130- Å Mo masks up to 60-keV¹¹B and 120-keV⁷⁵As. The implantation study covers the energy range from 15 to 70 keV for boron and from 40 to 160 keV for arsenic.