Diamond, with an ultra-wide band gap (UWBG) of 5.5 eV and the highest thermal conductivity of any material (2200 W/cm.K), is ideally suited for power conversion applications that demand high breakdown voltage and high current density. Work from Arizona State University has demonstrated p-i-n diodes with on-state current densities exceeding 100 kA/cm^2, and a reverse breakdown field of ~2 MV/cm. While these, and other results, confirm the promise of diamond-based semiconductor for power electronics, most demonstrations have used diamond substrates smaller than 10 mm x 10 mm in area. The lack of large area diamond substrates has, until recently, limited the manufacturable readiness level (MRL) of diamond as an electronic material. However, the recent availability of larger area diamond plates formed from mosaic tile arrays provides a road map for high volume manufacturing. Here we report the automated testing of Schottky-i-p diodes formed as an array of 3,600 devices on a 2x2 mosaic diamond plate with dimensions of 18 mm x 18 mm. The diodes show remarkably uniform electrical characteristics, even for those devices placed above the seams between the diamond tiles. The 2x2 mosaic tile plates were acquired from EDP Corporation of Japan, with the diode array fabricated by Advent Diamond. The device testing was performed using a FormFactor CM300xi probe system configured for automated probing and measurement of current-voltage (I-V), capacitance-voltage (C-V) and RF S-parameter characteristics. The data was used to extract the diode ideality factor, on-state resistance and off-state breakdown voltage, as well as the thickness of the intrinsic layer, and cut-off frequency figure-of-merit. Statistical analysis of 1000’s devices shows a tight distribution for each of these parameters. Despite concerns that growth defects originating at the tile seams might propagate into devices fabricated directly above them, it appears that the diodes on the seams are statistically identical to those away from them. This talk will describe the fabrication and test methods used to characterize the Schottky-i-p diodes. The results suggest that mosaic tile arrays are a promising approach for achieving large area diamond substrates. With 2” and 4” diameters wafers being available in the near future, it seems that diamond-based power electronics will soon be available with enhanced MRL.
