Tantalum Nitride as Electrode for MOS Technology and Schottky Diode

Abstract

TaN films have been used as gate electrodes in MOS capacitors, which were fabricated with 18 nm thick SiO2 as gate dielectric, and in Schottky diodes on n-type Si (100) substrates. TaN layer presented electrical resistivity of 327 μΩ.cm and poly crystalline structure. MOS capacitors and Schottky diodes were sintered in conventional furnace in forming gas at 450 °C for different annealing times between 5 and 30 min. MOS Capacitors and Schottky diodes presented TaN/SiO2/Si/Al and TaN/Si/Al structures and were electrical characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements. From C-V measurements, the extracted TaN work function values and effective charge densities were between 3.9 and 4.4 eV, 1010 and 1012 cm-2, respectively. From I-V measurements, the work function values between 4.3 and 4.4 eV were extracted. Both devices present excellent results, which indicate that TaN electrodes can be used for MOS Technology and Schottky Diode.