Insights into the Role of Plasma in Atmospheric Pressure Chemical Vapor Deposition of Titanium Dioxide Thin Films

Abstract

In this work, the effect of plasma on the chemistry and morphology of coatings deposited by Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition (AP-PECVD) is investigated. To do so, plasma deposited amorphous titanium dioxide (TiO2) thin films are compared to thin films deposited using Atmospheric Pressure Chemical Vapor Deposition (AP-CVD) not involving the use of plasma. We focus here on the effect and the interest of plasma in the AP-PECVD process over AP-CVD for low substrate temperature deposition. The advantages of AP-PECVD over AP-CVD are often suggested in many articles however no direct evidence of the role of the plasma for TiO2 deposition at atmospheric pressure was reported. Hence, herein, the deposition via both methods is directly compared by depositing coatings with and without plasma using the same CVD reactor. Through the control of the plasma parameters, we are able to form low carbon coatings at low temperature with a deposition rate twice faster than AP-CVD, clearly showing the interest of plasma. Plasma enhanced methods are promising for the deposition of coatings at industrial scale over large surface and at high rate.

Fourier‐transform infrared spectroscopy of ethyl lactate decomposition and thin‐film coating in a filamentary and a glow dielectric barrier discharge

“…Thin‐film deposition by plasma‐enhanced chemical vapor deposition (PECVD) on silicon wafers has first been investigated in the 60 s. Later, the PECVD technology was extended to atmospheric plasma (AP PECVD). [ 1–6 ] The main advantage of atmospheric pressure plasma is the ability to lower the costs for treating materials by avoiding pumping systems and enabling large surface treatments by a continuous process. Owing to its simple scalability from small laboratory reactors to large industrial installations and the homogeneity of deposited layer, dielectric barrier discharge (DBD) [ 7–9 ] is a good candidate for making a thin‐film polymer.…”

Effect of Annealing Temperature on Spatial Atomic Layer Deposited Titanium Oxide and Its Application in Perovskite Solar Cells

“…Metal oxides often require an annealing process to improve the density of the film, and the crystal structure of the film is strongly affected by the annealing temperature. The existing research on TiO 2 annealing is mostly based on sol-gel [ 8 , 31 ] or sputtering [ 32 ], where TiO 2 is reported to have mainly three types of crystal phases, an anatase phase at below 600 °C, rutile phase at above 800 °C and brookite mesophase. The crystal phase of TiO 2 also depends on the particle size, due to the interplay between the thermodynamic quantities, particularly the surface energy [ 33 ].…”

“…Among a wide variety of metal oxides, TiO 2 is a promising material for many emerging applications, such as gas sensors [1,2], dye-sensitized solar cells [3,4], photocatalysis [5] and gate insulators in metal-oxide-semiconductor field-effect transistors [6]. The characteristics of TiO 2 thin films prepared by sol-gel, chemical vapor deposition or sputtering have been extensively studied [7][8][9][10]. Fujishima et al reviewed the properties of TiO 2 prepared by various methods, the fundamentals of photocatalysts, as well as applications [11].…”

Atmospheric Pressure Plasma Deposition of TiO2: A Review

“…A higher O 2 concentration led to a high density of atomic oxygen, which then oxidized the precursor molecules before deposition, rendered them inactive, and hence resulted in a low deposition rate. Atmospheric pressure chemical vapor deposition without plasma also led to a much lower deposition rate compared to PECVD when similar experimental set-ups were used for both techniques, and thus makes PECVD attractive for its potential application in industry [83]. A recent study that used APP to coat polymer optical fibers with photocatalytic anatase TiO 2 thin films showed greater advantages of this method than other commonly used techniques, such as thermal CVD and wet chemical processes in functional coatings [84].…”