Reactive sputter deposition and characterization of tantalum nitride thin films

Electrical and structural properties of tantalum nitride films. deposited o n GaAs substrates by a d.c. magnetron sputtering technique at different nit rogen partial pressures for use as resistors in integrated circuits, have b een reported. Sheet resistivity measurements indicate that stoichiometric T aN films with stable resistivity values can be obtained if the nitrogen par tial pressure is maintained between 10.5 and 20.6%. Structural properties s tudied using X-ray diffraction indicate the presence of pure Ta, TaN, Ta3N5 or a mixture of Ta-N phases in the films depending on the amount of nitrog en in the sputtering gas. The temperature coefficient of resistivity measur ed for the films deposited with the nitrogen partial pressure around 13% sh owed a stable value of - 200 ppm K-1. Fabricated TaN thin-film resistors sh owed resistance values within +/- 10% of the designed value, suggesting the possibility of integrating these resistors with devices. (C) 1999 Elsevier Science S.A. AU rights reserved.