Fabrication and characterization of precise integrated titanium nitride thin film resistors for 2.5D interposer

Thin film resistors (TFRs) have been fabricated by an optimized process. Titanium nitride (TiN) was used as the resistor layer and was deposited by metal organic chemical vapor deposition MOCVD) process. H2-N2 plasma was applied after every cycle of TiN deposition to stabilize TiN films. The fabrication effects such as deposition of the isolation layer, and passivation layer as well as formation of contact holes on the TiN resistor layer have been investigated. The optimized process allowed the fabrication of stable and precise 25 nm and 35 nm thick TiN resistors with varying line widths and lengths. Electrical characteristics such as resistance, temperature coefficient of resistance (TCR), and isolation layer (SiO2) breakdown voltage were determined. TCR of TFRs decreased with the decrease in the resistor film thickness. Measured resistance values of all fabricated resistors approximated theoretical values within limits of ± 4 %. Resistance was measured at room temperature before and after thermal storage of the resistors at 250 °C and showed no significant change in value.