Effect of Rapid Thermal Annealing on Performances of Vertical Boron-Doped Diamond Schottky Diode with LaB6 Interlayer

We demonstrated the fabrication and operation of vertical diamond Schottky barrier diodes (SBDs) by inserting an ultrathin lanthanum hexaboride (LaB6) interlayer at the Zr/diamond interface. The rapid thermal annealing (RTA) effect on SBD electrical properties was investigated systematically by employing current-voltage and capacitance-voltage measurements. The results reveal that a suitable RTA treatment can significantly improve the device performance of diamond SBD with LaB6. After 350 degrees C annealing, a significant improvement of rectifying current curve with a forward current density over 2 kA/cm(2) is obtained, and this device also exhibits excellent diode behaviors with extremely high rectification ratio of 1.7 x 10(10) and low series resistance of 0.79 m Omega center dot cm(2), combining with Schottky barrier height of 1 eV, ideality factor of 1.78, and turn-on voltage of 2.3 V. Additionally, after 350 degrees C annealing, the turn-on voltage reduces while maintaining a reasonable breakdown performance. There is a process temperature window between 250 and 450 degrees C for RTA to obtained optimized Schottky interface. The RTA treatment can make certain effective improvement for this SBD via interface engineering.