Impact of Laser-Induced Graphitization on Diamond Schottky Barrier Diodes

Pseudovertical Schottky barrier diodes (SBDs) are fabricated on a single-crystal diamond substrate. Herein, the structural and electrical influence of laser-induced graphitization which takes place during the laser-dicing process is investigated. Before laser irradiation, the fabricated SBDs show a high rectifying ratio of more than 11 orders at +/- 10 V and undetectable leakage current. Ideality factor (n) and Schottky barrier height (phi (b)) are estimated to be 1.09 and 1.35 eV, respectively. After laser irradiation, the SBDs still exhibit good diode behavior, in which n and phi (b) values slightly change by 10%. Leakage current is increased about two orders of magnitude and breakdown voltage is degraded from 940 to 375 V due to the presence of graphite debris. After removing the graphite debris utilizing the oxygen plasma cleaning process through an inductively coupled plasma (ICP) system, all SBDs are recovered back to typical diode characteristics. It is found that strain and surface defects that may be introduced during laser dicing and post-ICP etching do not severely influence SBD characteristics.