Patterning of ALD HfO2 Layers on Silicon

Abstract

A patterning technology for very thin layers of HfO2 layers grown by atomic layer deposition is proposed and evaluated in the case of patterning on silicon. This technology makes use of atomic layer deposited Al2O3 as a buffer layer, thus preventing silicon surface damage during HfO2 dry etching. The final surface roughness of silicon and of the patterned HfO2 layer as measured by AFM indicates that the proposed technology successfully leaves the silicon surface undamaged. The effects of photomasks overlapping have also been evaluated, which have lead to some design rules and buffer layer thickness requirements.