Regular Article

Modelling of low-temperature/large-area distributed antenna array microwave-plasma reactor used for nanocrystalline diamond deposition^★

LSPM-CNRS, UPR 3407, Université Paris 13, Sorbonne Paris Cité, 99 Avenue J. B. Clément, 93430 Villetaneuse, France

^* e-mail: fabien.benedic@lspm.cnrs.fr

Received: 3 July 2017
Received in final form: 7 October 2017
Accepted: 29 November 2017
Published online: 27 February 2018

Abstract

In this paper we investigate a distributed antenna array Plasma Enhanced Chemical Vapor Deposition system, composed of 16 microwave plasma sources arranged in a 2D matrix, which enables the growth of 4-in. diamond films at low pressure and low substrate temperature by using H₂/CH₄/CO₂ gas chemistry. A self-consistent two-dimensional plasma model developed for hydrogen discharges is used to study the discharge behavior. Especially, the gas temperature is estimated close to 350 K at a position corresponding to the substrate location during the growth, which is suitable for low temperature deposition. Multi-source discharge modeling evidences that the uniformity of the plasma sheet formed by the individual plasmas ignited around each elementary microwave source strongly depends on the distance to the antennas. The radial profile of the film thickness homogeneity may be thus linked to the local variations of species density.