Modeling, design, and simulation of Schottky diodes based on ultrananocrystalline diamond composite films

Abstract

In this study, heterojunction diodes based on ultrananocrystalline diamond/hydrogenated amorphous carbon (UNCD/a-C:H) composite films, grown on Si substrates using the coaxial arc plasma deposition method, were modeled, characterized, and investigated. Calibrated material parameters, extracted from experimental analysis of nitrogen-doped (n-type) UNCD/a-C:H/p-type Si heterojunctions, were fed to the device model. Design of vertical geometry Pd/n-type UNCD/a-C:H Schottky diodes was proposed using a two-dimensional device simulator. Simulation results of diodes with field-plate termination exhibited a barrier height of 1 eV, turn-on voltage of 0.75 V, specific on-resistance (R s,on) of 70 mΩ cm2, and breakdown voltage (V BD) of 270 V. This corresponds to the power figure of merit (V BD 2/R s,on) of 1.04 MW cm−2. The results offer a promising potential of using nitrogen-doped UNCD/a-C:H in power electronics devices.

Determination of trap density-of-states distribution of nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films

“…A coaxial arc plasma gun (CAPG) equipped with pure graphite targets was fixed inside the deposition chamber. A capacitor of 720 μF and 100 V power supply was used to operate the CAPG [21][22][23][24][25][26][27][28][29][30][31][32] . The chamber was initially evacuated to a pressure less than 10 -5 Pa, using a turbo molecular pump.…”

“…The surface states density in Pd/n-type UNCD/a-C:H films was evaluated to be 1.7 × 10 15 cm -2 eV -1 for the slow response states, which decreased to 2.0 × 10 14 cm -2 eV -1 for the high-frequency response states [22] . Although the electrical and optical properties of N 2 -doped UN-CD/a-C:H films grown by the CAPD method have been extensively studied [23][24][25][26][27][28][29][30][31][32] , there have been very limited reports on defects in these films. In this study, defect properties and energy-distributed trap density-of-states (DOS) in UNCD/a-C:H films have been experimentally investigated.…”

Temperature-Dependent Impedance Spectra of Nitrogen-Doped Ultrananocrystalline Diamond Films Grown on Si Substrates

“…It is suggested that they (π C=N bonds) contribute to the enhancement of electrical conductivity due to the generation of unpaired electrons. We extensively investigated the electrical characteristics of n-type (UNCD/a-C:H)/p-Si heterojunctions fabricated by the CAPG method utilizing current-voltage (I-V) measurements under different conditions of temperatures and illuminations [16]- [21]. On the other hand, the contributions of the nanodiamond grains and the GBs to the electrical properties of nitrogen-doped (UNCD/a-C:H) have not been comprehensively investigated yet.…”