The Role of Oxygen Dissociation in Plasma Enhanced Chemical Vapor Deposition of Zinc Oxide from Oxygen and Diethyl Zinc

Abstract

The influence of electron impact dissociation of oxygen on neutral chemistry was studied for plasma-enhanced chemical vapor deposition (PECVD) of zinc oxide using oxygen and diethyl zinc. Electron conditions in the reactor were estimated based on simulations of well-known Ar-O 2 plasmas, while the majority of the thermal chemistry was abstracted from the combustion literature. A rudimentary model of film growth was developed using the rate of oxygen dissociation as the lone adjustable parameter. Model results were compared directly with experimental measurements of deposition rates and neutral species densities for a wide range of conditions. Good quantitative agreement between experiments and model were observed as a function of composition and rf power. The system is highly sensitive to the electron impact dissociation of oxygen, which creates the radical pool that drives the majority of the chemistry. The approach detailed here provides a framework for the development of models of oxide PECVD derived from other metalorganic precursors.

Effect of wall conditions on the self-limiting deposition of metal oxides by pulsed plasma-enhanced chemical vapor deposition

“…29 Modeling of our discharge indicates that the electron temperature is relatively low ͑ϳ2 eV͒, 22 so contributions from dissociative excitation should be minimal in this system, which is supported by the nominally identical response of the O atom lines at 777 and 844 nm. 29 The second reactor is a remote inductively coupled plasma system that has been used for alumina synthesis ͓Fig.…”

“…The organometallic precursor serves as the fuel, and deposition rates fall with increasing O atom density. [20][21][22] Taking this behavior to the extreme using a combination of fuel lean conditions and high rf power creates an environment in which the precursor is completely oxidized in the gas phase or sacrificially deposited before reaching the substrate. Under continuous wave ͑cw͒ operation at these conditions, the substrate is exposed to stable combustion products and a high flux of atomic O; no deposition occurs.…”

“…6,35 As detailed previously, the plasma composition and deposition rate in metal oxide PECVD systems depend critically on the O atom density. 22 Next, OES is used to monitor this critical parameter.…”

Selective Oxygen-Plasma-Etching Technique for the Formation of ZnO−FTO Heterostructure Nanotubes and Their Rectified Photocatalytic Properties

“…In this paper, we propose a fabrication method to synthesize ZnO−FTO composite nanotubes using water-based spray pyrolysis for depositing FTO NPs on arrayed ZnO NRs and oxygen plasma for the etching process. During the process, various ions and radicals generated by the oxygen plasma, including O + , O 2+ , and O*, can readily diffuse into oxygen vacancies − to create negative charges on the ZnO NR surface. This results in an accelerated etching rate, producing a large number of voids in ZnO and forming a hollow ZnO−FTO heterostructure.…”

An Analysis of the Deposition Mechanisms involved during Self‐Limiting Growth of Aluminum Oxide by Pulsed PECVD

“…The second component is analogous to PECVD, with deposition occurring through plasma-activated intermediates (M Ã ) produced at the initiation of each plasma pulse. [18,19] The detailed chemistry occurring at the start of each plasma pulse will be very complex, but conceptually we proposed that oxidation of an organometallic precursor such as TMA proceeds through reactions in series, as shown in Equation 1.…”