Method of Quantified Mass Spectrometry for Atomic Layer Deposition Fluidized Bed Reactors

Mass spectrometers have been used in-line on atomic layer deposition fluidized bed reactors (ALD-FBRs) to track the progress of the ALD reaction. However, the use of mass spectrometry or, more specifically, residual gas analysis for ALD-FBRs has been limited to qualitative measurements indicating the appearance and removal of ALD precursor and byproduct species. Here we provide a method to perform in situ gas species quantification using a residual gas analyzer (RGA) with an ALD-FBR. We explain how to propagate error sources across the ALD-FBR system to the final quantified mass value. Additionally, we present the first example of using an RGA to quantify in situ a reaction byproduct in an ALD-FBR. The trimethylaluminum (TMA)/water chemistry was conducted on single crystal LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) powder and the carbon dioxide byproduct was quantified for each ALD half reaction. The RGA quantification method presented in this work allows in situ surface characterization of the ALD reaction on a powder substrate. We envision ALD-FBR operators will be able to use the method for their own ALD chemistries and substrates, especially during the initial ALD cycles where the ALD precursors interact with the substrate surface and reactions besides the expected ALD reaction are likely to occur.