Spatial PEALD on Moisture-Containing Substrates and in High Moisture Backgrounds
(Room Room 104-A)
02 May 19
11:20 AM
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11:40 AM
Tracks:
Joint Session of Emerging Technologies and Plasma Processes Focused on Atomic Layer Processes (ALP)
To deposit high quality thin films using ALD, it is generally believed that the substrates and reaction chamber must be free of water and background water vapor. Most ALD metal precursors are highly reactive with water, and if any water is present during exposure to the metal precursor, a low quality CVD reaction will take place, degrading the film quality. For processes such trimethylaluminum-based ALD of Al2O3, this background water vapor can also result in vapor phase growth of Al2O3 particles, contaminating the film and the reactor. Substrates such as polymer lenses and films nominally contain significant amounts of water under ambient conditions, and require extended outgassing times to assure that no water remains prior to starting the ALD process, particularly when low substrate temperatures are required. In this work we demonstrate high speed spatial PEALD of SiO2 films using aminosilane precursors, with relatively high background levels of water vapor in the silicon precursor zone of the reactor, and on substrates containing significant amounts of water. The properties of these coatings, including refractive index, wet etch rate, and adhesion to the substrate, are shown to be similar to those of coatings produced under nominally dry conditions.