Can We Rationally Design and Operate Spatial Atomic Layer Deposition Systems for Steering the Growth Regime of Thin Films?

Abstract

Fine control over the growth of materials is required to precisely tailor their properties. Spatial atomic layer deposition (SALD) is a thin-film deposition technique that has recently attracted attention because it allows producing thin films with a precise number of deposited layers, while being vacuum-free and much faster than conventional atomic layer deposition. SALD can be used to grow films in the atomic layer deposition or chemical vapor deposition regimes, depending on the extent of precursor intermixing. Precursor intermixing is strongly influenced by the SALD head design and operating conditions, both of which affect film growth in complex ways, making it difficult to predict the growth regime prior to depositions. Here, we used numerical simulation to systematically study how to rationally design and operate SALD systems for growing thin films in different growth regimes. We developed design maps and a predictive equation allowing us to predict the growth regime as a function of the design parameters and operation conditions. The predicted growth regimes match those observed in depositions performed for various conditions. The developed design maps and predictive equation empower researchers in designing, operating, and optimizing SALD systems, while offering a convenient way to screen deposition parameters, prior to experimentation.

Enhancing control in spatial atomic layer deposition: insights into precursor diffusion, geometric parameters, and CVD mitigation strategies

“…This cyclic process allows for exceptional control over film thickness, composition, uniformity, and conformality at the atomic scale, making it ideal for applications requiring extreme precision such as nanoelectronic devices or ultrathin functional coatings. Furthermore, environmental concerns have underscored the need for sustainable deposition methods that minimize waste and energy consumption, making ALD an attractive choice due to its intrinsic efficiency [8][9][10]. However, conventional ALD also has some disadvantages, including slow deposition rates due to the sequential nature of the process, limited scalability for large-area coatings, and the requirement for specialized vacuum-based equipment, which can increase the cost and complexity of implementation.…”

“…One often prefers a small injection head with a close distance between gas channels to save deposition time. However, some previously published works have reported the possible chemical vapor deposition (CVD) contribution in SALD of thin films, mainly due to the cross-talk between precursor and counter-reactant in the gas phase when the related channels are spatially close [10,16,17]. For instance, Masse de la Huerta et al have demonstrated the CVD contribution in SALD of ZnO from diethylzinc (DEZ) and water vapor (H 2 O) when performing the static deposition.…”

Highly Transparent and Stable Flexible Electrodes Based on MgO/AgNW Nanocomposites for Transparent Heating Applications

“…[29][30][31][32][33][34][35][36][37] A promising alternative to ALD, known as AP-SALD, involves separating the precursor in space rather than time with continuous injection of the precursor. [38] Such approach results in higher deposition rates than conventional ALD, [39][40][41] and has been explored for the growth of high-quality materials for many optoelectronic applications at atmospheric pressure and low deposition temperatures. [42][43][44][45][46] However, to the best of our knowledge, there are no studies so far reporting the AP-SALD deposition of MgO.…”