Year-end Sale % OFF 
Abstract
Reaction mechanisms during the growth of multinary compounds by atomic layer deposition can be complex, especially for sulfide materials. For instance, the deposition of copper indium disulfide (CuInS2) shows a non-direct correlation between the cycle ratio, the growth per cycle of each binary growth cycles, i.e., CuxS and In2S3, and the film composition. This evidences side reactions that compete with the direct Atomic Layer Deposition (ALD) growth reactions and makes the deposition of large films very challenging. To develop a robust upscalable recipe, it is essential to understand the chemical surface reactions. In this study, reaction mechanisms in the Cu-In-S ternary system were investigated in-situ by using a quartz crystal microbalance system to monitor mass variations. Pure binary indium sulfide (In2S3) and copper sulfide (CuxS) thin film depositions on Al2O3 substrate were first studied. Then, precursors were transported to react on CuxS and In2S3 substrates. In this paper, gas-phase ion exchanges are discussed based on the recorded mass variations. A cation exchange between the copper precursor and the In2S3 is highlighted, and a solution to reduce it by controlling the thickness deposited for each stack of binary materials during the CuInS2 deposition is finally proposed.
Highlights
Atomic Layer Deposition (ALD) is a technique based on self-limited surface chemical reactions, where the precursors are injected successively in a reactor under vacuum and heated at a relatively low temperature [1,2,3,4]
The growth is non-linear as the estimated Growth Per Cycle (GPC) increases progressively until it reaches a constant value approximately equals to 0.32 ± 0.03 Å/cycle
This study is a deep investigation of the reaction mechanism and ion exchanges occurring in the ternary Cu-In-S system prepared by ALD from metal acetylacetonate precursors and H2 S
Summary
Atomic Layer Deposition (ALD) is a technique based on self-limited surface chemical reactions, where the precursors are injected successively in a reactor under vacuum and heated at a relatively low temperature [1,2,3,4]. The cycle sequence (i.e., the order of the precursor doses) and the cycle ratio (i.e., the number of cycles of one binary process vs the total number of cycles) are essential to obtain a homogeneous film. Nucleation delays, exchange mechanisms, growth rate, and temperature window differences complicate the deposition of such multinary compounds and make the control of the process parameters crucial [5,6,7].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
