0000000000670093
AUTHOR
Felix Mattelaer
Aluminum tri-isopropoxide as an alternative precursor for atomic layer deposition of aluminum oxide thin films
Due to the safety challenges associated with the use of trimethylaluminum as a metal precursor for the deposition of alumina, different chemicals have been investigated over the years to replace it. The authors have investigated the use of aluminum tri-isopropoxide (TIPA) as an alternative alkoxide precursor for the safe and cost-effective deposition of alumina. In this work, TIPA is used as a stable Al source for atomic layer deposition (ALD) of Al2O3 when different oxidizing agents including water, oxygen plasma, water plasma, and ozone are employed. The authors have explored the deposition of Al2O3 using TIPA in ALD systems operating in vacuum and atmospheric pressure conditions. For the…
A liquid alkoxide precursor for the atomic layer deposition of aluminum oxide films
For large-scale atomic layer deposition (ALD) of alumina, the most commonly used alkyl precursor trimethylaluminum poses safety issues due to its pyrophoric nature. In this work, the authors have investigated a liquid alkoxide, aluminum tri-sec-butoxide (ATSB), as a precursor for ALD deposition of alumina. ATSB is thermally stable and the liquid nature facilitates handling in a bubbler and potentially enables liquid injection toward upscaling. Both thermal and plasma enhanced ALD processes are investigated in a vacuum type reactor by using water, oxygen plasma, and water plasma as coreactants. All processes achieved ALD deposition at a growth rate of 1-1.4 angstrom/cycle for substrate tempe…
Atomic layer deposition of localised boron- and hydrogen-doped aluminium oxide using trimethyl borate as a dopant precursor
Atomic layer deposition (ALD) of boron-containing films has been mainly studied for use in 2D materials and for B-doping of Si. Furthermore, lithium-containing borates show great promise as solid electrolyte coatings for enhanced energy storage. In this work, we examine trimethyl borate (TMB) and triethyl borate (TEB) in combination with O2 plasma as precursors for ALD of B-containing films, targeting the growth of B2O3. It is found that films grown from TEB contain no boron. Further work with TMB as a boron-containing precursor showed promising initial growth on a SiO2 or Al2O3 surface, but a rapid decrease of the growth rate during subsequent ALD cycles indicating surface inhibition durin…
Atomic Layer Deposition of Localized Boron- and Hydrogen-Doped Aluminum Oxide Using Trimethyl Borate as a Dopant Precursor
Atomic layer deposition (ALD) of boron-containing films has been mainly studied for use in two-dimensional materials and for B doping of Si. Furthermore, lithium-containing borates show great promi...
Reaction pathways for atomic layer deposition with lithium hexamethyl disilazide, trimethyl phosphate, and oxygen plasma
Atomic layer deposition (ALD) of lithium-containing films is of interest for the development of next-generation energy storage devices. Lithium hexamethyl disilazide (LiHMDS) is an established precursor to grow these types of films. The LiHMDS molecule can either be used as a single-source precursor molecule for lithium or as a dual-source precursor molecule for lithium and silicon. Single-source behavior of LiHMDS is observed in the deposition process with trimethylphosphate (TMP) resulting in the deposition of crystalline lithium phosphate (Li3PO4). In contrast, LiHMDS exhibits dual-source behavior when combined with O2 plasma, resulting in a lithium silicate. Both processes were characte…