Electric field breakdown of lateral-type Schottky diodes formed on lightly doped homoepitaxial diamond

High breakdown voltage Schottky diodes synthesized on p‐type CVD diamond layer

“…The first reverse J ( V ) measurements performed up to 1 kV gave similar J ( V ) curves as previously published by Teraji et al 9, with very low dispersion even 9 months after the last VUV ozone treatment and metallization. J ( V ) tests at higher reverse voltages have been performed, by covering the sample with an insulating gel (fluorinert) to avoid a surface breakdown 5 or by putting the sample into a vacuum chamber at a pressure of 10 −6 Mb. The two latter J ( V ) measurements are shown in Fig.…”

“…Planar Schottky diodes have been processed. They consist of 400 nm thick titanium–gold ohmic contacts annealed under vacuum at 450 °C, and 49 circular gold Schottky contacts, with a diameter of 150 µm, after a surface treatment by vacuum ultra‐violet (VUV) 5 with the help a deep ultraviolet xenon lamp (wavelength of 172 nm). The metal deposition has been made through holes in a metallic mask, without any lithography step.…”

Extreme dielectric strength in boron doped homoepitaxial diamond

“…Various authors who have also implemented diodes made of a metal deposited on single crystalline diamond layers with boron doping concentration in the range of 10 15 -10 17 cm −3 showed lower limits of the maximum reverse voltage and avalanche breakdown fields not exceeding 4 MV/cm. [9][10][11][12] Higher fields were evidenced only in the case of boron concentrations near 10 18 cm −3 , 1,13,14 which are inappropriate for high voltage operation. Such low breakdown fields may be due to surface ͑or subsurface͒ 15 and interface defects rather than to the bulk properties of the diamond epilayer, since Teraji et al 16 have recently shown that a surface treatment based on ozone produced by a deep ultraviolet xenon lamp in vacuum ͑vuv, wavelength of 172 nm͒, decreases the reverse current density under 1 kV bias voltage at much smaller values than achieved by any other treatment.…”

p‐type diamond Schottky diodes fabricated by vacuum ultraviolet light/ozone surface oxidation: Comparison with diodes based on wet‐chemical oxidation

“…In vacuum condition the diode VUV sustain up to 300 V but the current rapidly increases above this voltage. We attribute this effect to surface discharge 11, whereas by covering the sample with insulating liquid it was suppressed and it is possible to reach up to 1 kV 5. In case of the diode WO3 no differences are observed from the J – V characteristics in vacuum and those with the insulating liquid: the current is dominated by surface leakage.…”