Contact property between metal and tantalum nitride film characterized by using transmission line model

Contact property between metal electrodes and a tantalum nitride (TaNx) layer was characterized by transmission line model (TLM). The TaNx films were deposited by reactive sputtering. The electrode material was an Au layer prepared by sputtering. An interfacial layer was inserted between the electrodes and the TaNx layer to improve the contact performance. The specific contact resistivity was determined by TLM method, and was the order of 10−8 Ω m2. The sub-mount packaging module with TaNx film resistor for laser diode was fabricated on a ceramic substrate with varying surface roughness and the relation between surface roughness and resistance was discussed.