Uniform coating of Ta₂O₅ on vertically aligned substrate: A prelude to forced flow atomic layer deposition

Uniform tantalum oxide thin films, with a growth rate of 0.6 Å/cycle, were fabricated on vertically aligned, 10 cm-long, silicon substrates using an innovative atomic layer deposition (ALD) design. The ALD system, with a reaction chamber depth of 13.3 cm and 18 vertical enclosed channels (inner diameter 1.3 cm), was coupled with a shower-head type precursor conduit plate bearing 6 radial channels. This design enabled deposition on 6 silicon substrates at a time. The degrees of non-uniformity of deposits along the length of the silicon wafer and across different positions in the ALD chamber were found to be 1.77%-6.21% and 3.27%-5.45%, respectively. A further advantage of the design is that the conduit plate may be modified and the number of channels increased to process 18 substrates simultaneously, thus moving toward efficient and expedited ALD systems.