Plasma-Enhanced Atmospheric-Pressure Spatial ALD of Al2O3 and ZrO2

Abstract

Spatial Atomic Layer Deposition is emerging as an industrial thin-film manufacturing technology [1]. The technique is becoming so popular since it combines all advantages of conventional ALD (ultimate control of layer thickness and conformality over 3D-topologies, superior film material properties) with far higher deposition rates and processing at atmospheric pressure by means of spatial separation of the reactive gases. The integration of non-thermal plasma in spatial ALD reactors is expected to widen the thermal ALD process window towards lower operation temperatures and to enable to growth of specific materials requiring radicals (O, N, H, OH, NH, etc.). To this end, novel plasma sources with exceptional dimensional and chemical stability are required which provide the flow geometries optimized for efficient radical transport. This paper reports on our preliminary efforts to provide and examine the required linear scalable plasma sources. The effectiveness of close-proximity direct and remote plasma sources [2] are demonstrated using the deposition of thin dielectric films of Al2O3 and ZrO2 at temperatures ranging from room temperature to 100 oC. Both direct and remote plasma sources of the so-called surface DBD-type (Dielectric Barrier Discharge) can be applied for spatial ALD using the usual metal precursors and O2/N2 plasma. The advantage of the remote plasma option is avoidance of electrical source-substrate interaction which is often the cause of layer or substrate damage as a result of filamentary plasma discharges impacting the substrate. P. Poodt, et al., J. Vac. Sc. Technol. A, 30 010802-1 (2012). Y. Creyghton et al., Patent publication WO2015199539, Dec. 30 (2015).