Experimental Study of Process Emissions From Atomic Layer Deposition of Al2O3 Under Various Temperatures and Purge Time

Author(s):  
Lulu Ma ◽  
Dongqing Pan ◽  
Yuanyuan Xie ◽  
Fenfen Wang ◽  
Chris Yuan

Experimental investigations of process emissions from atomic layer deposition (ALD) of Al2O3 are accomplished under various temperatures and purge times to understand its environmental sustainability performance. About 93% of Trimethylaluminum (TMA) is found flowing through ALD system without deposition. 2–9 × 104 of ultrafine nanoparticles containing 51.9 ± 4.6% of C, 16.6 ± 0.9% of Al, 31.4 ± 4.1% of O are generated during each cycle of reactions. 0.34–0.38 cm3 of CH4 (25 °C, 1 atm), which takes up 45–51% of C contained in TMA is produced simultaneously. The concentration of nanoparticles drops with the increase of purge time. CH4 also has a trend of decreasing but acts more complex with the largest emission at a short purge time. Compared with temperature, which has limited effects on reactants, purge time changes the time of reaction as well as the degree of gas phase mixing, and therefore greatly influences ALD emissions.

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1456
Author(s):  
Bozhidar I. Stefanov ◽  
Blagoy S. Blagoev ◽  
Lars Österlund ◽  
Boriana R. Tzaneva ◽  
George V. Angelov

We report on the photocatalytic activity of ZnO layers deposited by atomic layer deposition on a porous anodic aluminum oxide substrate with hexagonal pore symmetry and varied pore dimensions. ZnO/Al2O3 composites were prepared with pore diameters in the range 93–134 nm and interpore distance in the range 185–286 nm, and their photocatalytic activity was measured for gas-phase photocatalytic oxidation of acetaldehyde at varying UV illumination intensities (0.08–3.94 mW cm−2). The results show that substrates with narrower pore diameters (<115 nm, in the case of this study) have a detrimental effect on the photocatalyst performance, despite their higher effective surface. The results are explained on the basis of limited mass transfer inside the porous structure and can be used as a guideline in the purposeful design of photocatalysts with a nanoporous or nanotubular structure.


Sign in / Sign up

Export Citation Format

Share Document