Chemical vapor deposition of diamond on silicon substrates coated with adamantane in glycol chemical solutions

Diamonds were synthesized on adamantane-coated mirror-polished Si (100) substrates by microwave plasma chemical vapor deposition (MPCVD) using a gas mixture of H₂ and CH₄. Before MPCVD deposition, Si substrates were dip-coated in chemical solutions of ethylene glycol and diethylene glycol with adamantane. With the coating of adamantane, the diamond nucleation can be enhanced with a density over 1 × 10⁸ cm ^-2 and the deposited diamond films are shown to be of good crystallinity by scanning electron microscopy and Raman spectrometry. The study demonstrates a simple and efficient way of diamond deposition on a smooth Si substrate.