High Conductivity Hydrogenated Boron and Silicon Co-Doped Diamond With 0.46 mm Ohmic Contact Resistance

We report on achieving high conductivityhydrogenated boron (B) and silicon (Si) co-doped diamondwith a room-temperature Hall result of a square resistanceof 2724 ohm/sq, a sheet hole density of 3.3x10(13)cm(-2),and a hole mobility of 68.9 cm2/Vs. The co-doping of Band Si is realized in such a way. First, etch solid BN diskby hydrogen plasma in microwave plasma chemical vapordeposition (MPCVD) system to form B source, and sputterSi film on the diamond surface, and then etch the Si filmon diamond sample by hydrogen plasma at 1000(degrees)C in thesame MPCVD chamber, and B/Si diffuse to dope diamond.The secondary ion mass spectroscopy of the sample showsthat at a depth of 0.3 mu m, the B and Si doping concentrationis higher than 1.0x1017cm-3, and the highest B andSi doping concentration at the surface is 3.7x10(20)cm(3)and 1.1x10(20)cm(-3), respectively. By using Au to form the ohmic contact electrode, the sample achieves the lowohmic contact resistance of 0.46mm and the contactresistivity of 1.6x10(-5)Omega cm(2). The B and Si co-dopeddiamond provides a new idea for the ohmic contact processoptimization of diamond FET devices