Preparation of High Conductivity Hydrogenated Silicon-Doped Diamond and MOSFET

Hydrogenated silicon-doped (Si-doped) diamond was prepared by magnetron sputtering silicon on IIa CVD diamond surface and following Si etch/diffuse process at 1000 °C in a hydrogen atmosphere in MPCVD. The silicon doping concentration was higher than
$1\times 10^{{18}}$
cm−3 among the depth of 25 nm. The hydrogenated Si-doped diamond surface demonstrated the simultaneous presence of C–H and C–Si bonds in the X-ray photoelectron spectroscopy (XPS) results, and a square resistance of 5500
$\Omega $
/sq with the hole concentration of
$1.4\times 10^{{13}}$
cm−2 by contact Hall test. MOSFET fabricated on the hydrogenated Si-doped diamond using traditional hydrogenated diamond device process showed decent device performance. The gold/hydrogenated Si-doped diamond electrodes showed ohmic contact resistivity of
$1.02\times 10^{-{5}}\,\,\Omega \cdot $
cm−2 and a contact resistance of 2.4
$\Omega \cdot $
mm. Besides, the 1.5-
$\mu \text{m}$
MOSFET device with a threshold voltage of 1.4 V delivered the maximum drain current, ON-resistance, maximum transconductance, and ON/ OFF ratio of −270.5 mA/mm, 39.6
$\Omega \cdot $
mm, 42.4 mS/mm and 8 orders of magnitude. The gate breakdown field and the OFF-state source-drain breakdown field reached 8.4 and 2.17 MV/cm, respectively. The hydrogenated Si-doped diamond provided a promising route for the preparation of high-performance diamond FET devices.