Almost Ideal Thermionic-Emission Properties of Ti-Based 4H-SiC Schottky Barrier Diodes

We have carefully investigated a number of more than 120 selected chips fabricated on one wafer, by I-V measurements at two different precisely controlled temperatures and precision CV measurements at room temperature. From these measurements the net-doping concentration, the C-V (flat-band) barrier ΦCV, the ideality n, the apparent Richardson constant Aapp and the apparent I-V barrier Φapp have been extracted for each chip. An extremely unique C-V barrier was determined showing a relative standard deviation (sigma over mean) of only 0.086%. Moreover, the average ideality n was found to be as low as 1.028 exhibiting a relative standard deviation of only 0.35%. A clear linear correlation (ρ2 = 0.968) between ideality n and apparent I-V barrier was observed. The effective Richardson constant A** of 4H-SiC in 〈0001〉 directions could therefore be extracted to be most likely in the interval 70 Acm-2K-2