| AVS 66th International Symposium & Exhibition | |
| Atomic Scale Processing Focus Topic | Monday Sessions |
| Session AP+2D+EM+PS+TF-MoM |
| Session: | Area Selective Deposition and Selective-Area Patterning |
| Presenter: | Paul Poodt, Holst Centre / TNO, The Netherlands |
| Authors: | A. Mameli, Holst Centre / TNO, The Netherlands F. Roozeboom, Holst Centre / TNO, The Netherlands P. Poodt, Holst Centre / TNO, The Netherlands |
| Correspondent: | Click to Email |
Area-selective atomic layer deposition (AS-ALD) has great potential in reducing cost by maskless device manufacturing of patterned layers. Still, in this new bottom-up approach the selectivities currently obtained for film growth on patterned growth areas vs. that on the non-growth areas are often very limited. Also the substrate throughput values for conventional low-pressure ALD is too low for industrial acceptance.(1,2) In this work we present a process for AS-ALD of SiO2 using intermittent plasma etch-back steps to increase the selectivity above 10 nm film thickness.(3) In addition, the deposition process itself is performed in a spatial ALD reactor at atmospheric pressure which allows for achieving high throughput.(4)
AS-ALD of SiO2 on a substrate with pre-patterned SiO2 and ZnO areas was demonstrated using a highly chemo-selective inhibitor that chemisorbs preferentially on the non-growth area (ZnO) while allowing the deposition of SiO2 on the growth area (SiO2). In order to maximize the process selectivity, a blanket fluorocarbon plasma etch-back step was interleaved after every 110 ALD cycles. This way, selective SiO2 deposition up to ~ 30 nm film thickness was demonstrated. Furthermore, X-ray Photoelectron Spectroscopy was carried out to verify the selectivity of the process: no Si was detected (detection limit 0.3 at. %) on the non-growth area, demonstrating the high selectivity of the process.
The process presented here combines selective inhibitor chemisorption, plasma-based spatial ALD with high deposition rates and plasma etch-back steps to correct for selectivity loss. This approach is compatible with roll-to-roll and sheet-to-sheet concepts and can therefore enable high-throughput AS-ALD on large-area and flexible substrates.
[1] A. Mameli, et al., ACS Nano, 11, 9303 (2017).
[2] F.S.M. Hashemi, et al., ACS Nano, 9, 8710 (2015).
[3] R. Vallat, et al., J. Vac Sc. Technol. A, 35, 01B104 (2017).
[4] P. Poodt, et al., Adv. Mater., 22, 3564 (2010).