Erbium doped yttria thin films deposited by injection CVD

Abstract
The deposition of Er doped Y₂O₃ thin films by a pulsed injection assisted MO-CVD process is studied. Well crystallised Er : Y₂O₃ films with a columnar growth structure were deposited between 600°C and 900°C. In some cases a monoclinic phase was obtained with the classical yttria cubic phase. The preferential crystalline orientation for the cubic phase ( [111] or [100] ) depended on the deposition temperature and on the oxygen content of the carrier gas. Because the Er and Y precursors are chemically similar (Er or Y tetramethylheptanedionate), the composition of the deposited films are closed to the composition of the solution. The Er luminescence was obtained for all the as deposited samples. The green and Infrared⁴I_13/2 → ⁴I_15/2 transition were observed. The lifetime of ⁴I_13/2 level increased with the deposition temperature. The lifetime of the ⁴I_13/2 level decreased with the erbium content due to up conversion effect. A lifetime of 7.5ms, closed to the bulk value, was obtained at low erbium concentration.