X-ray diffraction and electrical characterization of photo-CVD zirconium oxide layers

Zirconium oxide thin films grown by photo-induced chemical vapor deposition incorporating excimer UV lamps at deposition temperatures between 50 and 350 °C have been explored. The as-deposited ZrO2 films grown at 200 °C exhibited a good leakage property with a current density of ∼3.0×10−5 A/cm2 at an electric field of 1 MV/cm, which was further improved to ∼2.0×10−6 A/cm2 after an UV anneal in O2 at 400 °C for 10 min. With the annealing step, very few positive fixed charges with a Qf value of ∼2.0×1010 and ∼3.0×109 cm−2 for the 200 and 300 °C deposited films were present near the ZrO2/Si interface while the 300 °C deposited films also exhibited a lower interface trap density of 6.6×109 cm−2 eV−1. The as-deposited photo-CVD ZrO2 layers started to crystallise at a temperature of 250 °C, giving a refractive index value of ∼2.1 at the temperature just above 300 °C.