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

MetadataDetails
Publication Date2023-11-08
JournalIEEE Electron Device Letters
AuthorsJinfeng Zhang, Qi He, Zeyang Ren, Xinxin Yu, Kai Su
InstitutionsXidian University
Citations2

We report on achieving high conductivity hydrogenated boron (B) and silicon (Si) co-doped diamond with a room-temperature Hall result of a square resistance of 2724 ohm/sq, a sheet hole density of 3.3×10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;13&lt;/sup> cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-2&lt;/sup> , and a hole mobility of 68.9 cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sup> /Vs. The co-doping of B and Si is realized in such a way. First, etch solid BN disk by hydrogen plasma in microwave plasma chemical vapor deposition (MPCVD) system to form B source, and sputter Si film on the diamond surface, and then etch the Si film on diamond sample by hydrogen plasma at 1000 °C in the same MPCVD chamber, and B/Si diffuse to dope diamond. The secondary ion mass spectroscopy of the sample shows that at a depth of 0.3 μm, the B and Si doping concentration is higher than 1.0×10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;17&lt;/sup> cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-3&lt;/sup> , and the highest B and Si doping concentration at the surface is 3.7×10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;20&lt;/sup> cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-3&lt;/sup> and 1.1×10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;20&lt;/sup> cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-3&lt;/sup> , respectively. By using Au to form the ohmic contact electrode, the sample achieves the low ohmic contact resistance of 0.46 Ω·mm and the contact resistivity of 1.6×10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-5&lt;/sup> Ω·cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sup> . The B and Si co-doped diamond provides a new idea for the ohmic contact process optimization of diamond FET devices.