Wet etching characteristics and surface morphology evaluation of MOCVD grown HfO2 film

In this work, we have investigated the wet etching of MOCVD grown HfO2 film using diluted HF. The effect of various implant species on the etch rate was also extensively studied. Etch depth profile for as-deposited film shows that etch rate is higher at the surface and near the interface compared to its bulk. A ~15 A interfacial layer is unable to etch completely. The etch rate for annealed samples, prior to implant, is negligible due to crystallization. BF2, and As implanted samples after RTA show enhanced etching in DHF. The etch rate of As implanted samples are faster than BF2. However, B and P implanted samples shows negligible etch rate. Effect of implant species on surface roughness is not substantial. All samples show a RMS surface roughness (2-3 A ) after RTA. Etched samples show large surface roughness (max: 26 A ).