Effect of plasma composition on nanocrystalline diamond layers deposited by a microwave linear antenna plasma‐enhanced chemical vapour deposition system
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2015-06-30 |
| Journal | physica status solidi (a) |
| Authors | Andrew Taylor, Petr Ashcheulov, Martin Čada, Ladislav Fekete, Pavel Hubı́k |
| Institutions | Czech Academy of Sciences, Institute of Physics, University of Pardubice |
| Citations | 19 |
Abstract
Section titled “Abstract”The addition of CO 2 into the process gas has a significant impact on the quality and the incorporation of boron in CVD diamond layers. In this report we study the effect of CO 2 addition in the gas phase on the properties of boron doped nano‐crystalline diamond (BNCD) layers grown at low substrate temperatures (450-500 °C) using a microwave linear antenna plasma‐enhanced chemical vapour deposition apparatus (MW‐LA‐PECVD). Experimental results show an increase in the layers’ conductivity with a reduction in CO 2 concentration, which is consistent with the variation in the atomic boron emission line intensity measured by optical emission spectroscopy (OES). At CO 2 concentrations close to zero, we observed the formation of a smooth, transparent and highly resistive layer on unseeded substrates. This layer has been identified as silicon carbide (SiC) by transmission electron microscopy and X‐ray photoelectron microscopy. The presence of silicon in the plasma is confirmed by OES and it is attributed to quartz tube etching. In this specific deposition condition, diamond growth is in competition with SiC growth, which affects the diamond layer properties. SEM image of layer growth on a silicon substrate at low CO 2 concentration on unseeded area (left) with a smooth, highly resistive and transparent SiC layer and seeded area (right) with a boron doped nano‐crystalline diamond layer.