Foundations of plasma enhanced chemical vapor deposition of functional coatings

Abstract

Since decades, the PECVD (“Plasma Enhanced Chemical Vapor Deposition”) processes have emerged as one of the most convenient and versatile approaches to synthesizing either organic or inorganic thin films on many types of substrates, including complex shapes. As a consequence, PECVD is today utilized in many fields of application such as microelectronic circuit fabrication, optics/photonics, biotechnology, energy, smart textiles, and many others. Nevertheless, owing to the complexity of the process including numerous gas phase and surface reactions, the fabrication of tailor-made materials for a given application is still a major challenge in the field making it obvious that the mastery of the technique can only be achieved through the fundamental understanding of the chemical and physical phenomena involved in the film formation.
In this context, the aim of this foundation paper is to share with the readers our perception and understanding of the basic principles behind the formation of PECVD layers considering the co-existence of different reaction pathways that can be tailored by controlling the energy dissipated in the gas phase and/or at the growing surface. We demonstrate that the key parameters controlling the functional properties of the PECVD films are similar whether they are inorganic or organic-like (plasma polymers) in nature, thus supporting a unified description of the PECVD process. Several concrete examples of the gas phase processes and the film behavior illustrate our vision.
To complete the document, we also discuss the present and future trends in the development of the PECVD processes and provide examples of important industrial applications using this powerful and versatile technology.

Numerical optimization of dielectric properties to achieve process uniformity in capacitively coupled plasma reactors

“…Capacitively coupled plasmas (CCPs) are increasingly being used for a variety of critical thin-film processes with satisfactory uniformity and efficiency [1,2]. Owing to its functional usefulness, CCP is often adopted in the plasma enhanced chemical vapor deposition (PECVD) process for the production of state-of-the-art microchips despite various technical difficulties in the design of CCP reactors [3][4][5]. The recent requirement that the deposition unevenness of the film deposited on the wafer be less than 1%-3% has prompted growing interest in solving the technical problems surrounding the implementation of a uniform deposition process [6,7].…”

CFD-DEM model of a cold plasma assisted fluidized bed powder coating process

“…It is named thermal or non-thermal plasma, whether in equilibrium or not. When used in conjunction with appropriate gases or vapors that can create reactive species, non-thermal plasmas offer a platform to generate thin coatings on a wide variety of substrates (Snyders et al, 2023). Typically, these coatings or functionalizations are made by polymerization of monomers or coating precursors.…”

Designing Nanostructured Organic-Based Material by Combining Plasma Polymerization and the Wrinkling Approach

“…1,2 Among the numerous plasma-based techniques, the plasma polymerization belonging to the PECVD ("plasma enhanced chemical vapor deposition") family appears particularly attractive to synthesize organic thin polymer films, the so-called plasma polymer films (PPFs). 3 Briefly, plasma polymerization consists of the activation of an organic vapor into a plasma phase, resulting in the formation of reactive species (including radicals and to a lesser extent ions), followed by their condensation on surfaces exposed to the discharge. The molecular growth mechanism, comprising a complex interplay between surface and gas phase reactions, triggers the uniqueness of PPF such as the absence of a repeating unit in their polymeric network and the outstanding range of chemical compositions they can exhibit, combined with their thermal stability and their good adhesion properties on all kinds of substrates (i.e., metals, polymers, oxides) for instance.…”

“…For many years, plasma technologies have been gaining increasing attention for their ability to tune the surface properties of materials by activating the surface or depositing a thin film on it. , Among the numerous plasma-based techniques, the plasma polymerization belonging to the PECVD (“plasma enhanced chemical vapor deposition”) family appears particularly attractive to synthesize organic thin polymer films, the so-called plasma polymer films (PPFs) . Briefly, plasma polymerization consists of the activation of an organic vapor into a plasma phase, resulting in the formation of reactive species (including radicals and to a lesser extent ions), followed by their condensation on surfaces exposed to the discharge.…”