Overcoming the impact of post-annealing on uniformity of diamond (100) Schottky barrier diodes through corrosion-resistant nanocarbon ohmic contacts

Abstract

Diamond-based Schottky barrier diodes (SBDs) are involved in many technological applications. In a conventional SBD fabrication process that involves interface carbide forming ohmic contacts, a post-annealing step is necessary for ohmic contacts to achieve their operational efficiency. However, this step deteriorates the essential oxygen coverage at the diamond surface which in turn affects SBDs uniformity. So, an additional oxygen termination step is necessary prior to Schottky metal deposition. In this study, a non-conventional fabrication method is introduced using corrosion-resistant nanocarbon ohmic contacts fabricated by coaxial arc plasma deposition. As a result, The SBD parameters including ideality factors and barrier heights exhibited high uniformity with a very small standard deviation for the proposed fabrication process flow when compared with process flow including a post-annealing step. Furthermore, the contact behavior of nanocarbon ohmic electrodes is investigated on a heavily boron-doped diamond film using circular transmission line model theory and a specific contact resistance of ~ 10-5 Ωcm2 is obtained, suggesting the practical application of nanocarbon ohmic contacts for diamond-based electronic devices.

Pseudo‐Vertical Schottky Diode with Ruthenium Contacts on (113) Boron‐Doped Homoepitaxial Diamond Layers

“…Ti, Mo, and Ru contacts were annealed at 650 °C, i.e., at a temperature much higher than 500 °C, when the oxygen dipoles at the interface are disturbed. [ 22,23 ] The thermally annealed p ‐type diamond surface then behaves like a partial pinning‐free surface and a stronger dependence of the barrier on the metal work functions is observed. [ 1 ] Moreover, increasing the annealing temperature also brings the possibility of molybdenum (Mo 2 C) and titanium (TiC) carbide formation.…”

Maximizing visible Raman resolution of nanodiamond grains fabricated by coaxial arc plasma deposition through oxygen plasma etching optimization

“…The scientific interests in ultrananocrystalline diamond (UNCD) find their applications in interdisciplinary research areas of quantum technology, hard coating, radiation detection, power electronics, etc. [1][2][3] The control over charge transfer through donor impurityinduced mid-gap states at the grain boundaries makes UNCD a possible replacement for n-type single-crystalline diamonds. 4 As the room temperature activation energies of donor impurities in singlecrystalline diamonds (phosphorus = 0.6 eV and nitrogen = 1.7 eV) and the intricate fabrication process extend the reliability of UNCD films.…”

“…The scientific interests in ultrananocrystalline diamond (UNCD) find their applications in interdisciplinary research areas of quantum technology, hard coating, radiation detection, power electronics, etc 1–3 . The control over charge transfer through donor impurity‐induced mid‐gap states at the grain boundaries makes UNCD a possible replacement for n‐type single‐crystalline diamonds 4 .…”