ALD Approach toward Electrodeposition of Sb[sub 2]Te[sub 3] for Phase-Change Memory Applications

This paper describes various studies undertaken to devise a deposition cycle for the formation of , a phase-change memory material, by electrochemical atomic layer deposition (EC-ALD). The importance of deposition potentials to the formation of deposits of Sb and Te, were investigated. The resulting potentials were then used in an EC-ALD cycle to form deposits one atomic layer at a time, using a sequence of surface limited reactions. The optimal deposition potentials for the EC-ALD cycle, on a Au substrate, consisted of for Sb deposition, and for Te. Bulk Te stripping at was performed at . The conditions using a TiN substrates included Sb deposition at , Te deposition, and bulk stripping at and , respectively. The deposits obtained were stoichiometric, with a atomic ratio of 1.5 from electron probe microanalysis. Glancing angle X-ray diffraction studies showed a (015) preferred orientation for the deposit. was shown to grow successfully on patterned TiN substrates with vias.