Investigation of silicon-vacancy center formation during the CVD diamond growth of thin and delta doped layers

Abstract

The results are presented for the deposition of silicon-doped epitaxial diamond layers in a microwave CVD reactor. The study was aimed at the creation of silicon-vacancy color centers. The relation between the optical spectra of plasma emission, the concentration of silicon in diamond, and the intensity of photoluminescence of the formed color centers is investigated, depending on the silane content in the gas mixture. It is found that at a high silane content (SiH₄/CH₄ more than 2%), the mechanism of silicon incorporation in diamond changes, which leads to a substantially non-uniform distribution of silicon concentration in the epitaxial layer and a decrease in the photoluminescence intensity of silicon-vacancy centers. The conditions are determined and the creation of a silicon-doped diamond layer of nanometer thickness – a delta layer with a thickness of 5 nm and a silicon concentration of 1.7 × 10¹⁸ cm⁻³ – is demonstrated.