Growth of CuGaS2 by alternating-source-feeding MOVPE

Synthesis of Doped, Ternary, and Quaternary Materials by Atomic Layer Deposition: A Review

“…In the majority of cases found in Tables –, the supercycle scheme is used to combine two separate binary ALD processes that share one element (e.g., O, N, S) into a single ternary process. Some studies implement deposition with multiconstituent precursors to introduce more than one atom into the film with a single precursor, ,,− ,,,,− and others eschew the supercycle pulsing strategy in other ways ,,,− ,− as discussed in Section ; however, these are far less common among the works shown in the tables. Regarding the use of these alternative approaches, Si-containing compounds are of particular note as SiO 2 itself is often difficult to grow on its own. ,,,,,, A number of studies have successfully deposited Si-containing materials by ALD by using precursor strategies other than supercycles.…”

“…In the absence of characterization to elucidate these effects, the ALD processes may be run under nonoptimized conditions (e.g., subsaturation) which can lead to deviation from the expected growth characteristics. Finally, the effect of growth temperaturewhich is typically around 200–250 °Cis rarely explored, and when it is, these more complex materials do not often show the presence of an ALD temperature window. ,,,,, These many potential sources of nonidealities and complex behavior make studying multicomponent systems challenging.…”

“…In ternary materials, multiple phases are often thermodynamically stable, but in many applications one specific crystalline phase is preferred to achieve the desired properties. Ternary or quaternary materials grown by ALD are most commonly amorphous as-deposited, although this microstructure is less common for nitrides − , and for processes performed at higher temperatures. ,,,,− Consequently, most films must be annealed in order to induce crystallinity. Some general strategies to control the phase of multicomponent films deposited via ALD which will be discussed here include studying the bulk phase diagram of the material to appropriately tune composition and annealing conditions, tailoring atomic size and temperature to affect diffusion, and optimizing the supercycle recipe.…”