Influence of Ge precursors toward atomic layer deposition of germanium tellurides: A DFT study

초록

Germanium telluride (GeTex) has attracted significant research interest for its applications in phase-change memory devices and thermoelectric materials. Experimental studies on atomic layer deposition (ALD) of GeTex have shown that the choice of Ge precursor has a profound effect on the properties of the deposited film. In this work, the potential reactions of HGeCl3 and GeCl4 during ALD of GeTex were studied using density functional theory (DFT) calculations. It is found that gaseous HGeCl3 would spontaneously dissociate into GeCl2 and HCl under the ALD process conditions. Subsequently, the surface adsorption of the in situ-generated GeCl2 could achieve the desired 1:1 stoichiometry of GeTe. In contrast, GeCl4 does not decompose spontaneously, exhibiting lower reactivity compared to GeCl2. These findings provide insights into the intricate chemistry of GeTe ALD and highlight the importance of precursor selection, potentially offering strategies to control the properties of GeTex films.

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