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 degrees C in a hydrogen atmosphere in MPCVD. The silicon doping concentration was higher than 1 x 1018 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 St/sq with the hole concentration of 1.4 x 1013 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 x 10-5 Qcm-2 and a contact resistance of 2.4 Stmm. Besides, the 1.5-mu 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 Stmm, 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.