Plasma enhanced chemical vapor deposition of p-type Cu2O from metal organic precursors

Abstract

The scope of this work was to optimize the reactant delivery parameters for the plasma enhanced chemical vapor deposition (PECVD) of p-type [Formula: see text] films from Cu(hfac)(tmvs), with the aim to explore an alternative to other large-area deposition techniques such as sputtering. While n-type metal oxide semiconductors such as amorphous indium gallium zinc oxide have now been developed and offer significantly improved device performance over hydrogenated amorphous silicon, with devices achieving mobilities [Formula: see text], there is still an absence of good p-type inorganic semiconductors that provide similar performance. [Formula: see text] is a promising p-type metal oxide, but there remain limitations on the industrial scalability of some of the deposition processes demonstrated so far. PECVD has been scaled for uniform deposition on generation 10 display glass ([Formula: see text]) and so provides a viable alternative. The [Formula: see text] films deposited in this work achieved a Hall mobility of [Formula: see text] and were stable over a period of months. Contrary to previous reports of an “incubation” period, the initial growth rate during and immediately following nucleation was ([Formula: see text]40 nm/pulse) 10 times greater than the steady state growth ([Formula: see text]4 nm/pulse) achieved later in the deposition. Topographical scaling methods and fractal analysis of the film surface morphology using atomic force microscopy, at different stages during growth development, link this shift to a regime transition from growth dominated by surface diffusion to volume diffusion.