Determination of 4H-SiC Ionization Rates Using OBIC Based on Two-Photon Absorption 

Abstract

Optical Beam Induced Current (OBIC) measurements are performed on 4H-SiC avalanche diodes with a very thin and a highly doped active region. A pulsed green laser, with a wavelength of 532 nm, illuminates a reverse biased diode leading to generate electron-hole pairs in the space charge region. Comparison between the 4H-SiC bandgap and the incident photon energy shows that single photon absorption process can be neglected and two-photon absorption process dominates in this case. Ionization rates are then extracted from multiplication curve in a high electric field range (3 to 5 MV.cm–1). Results are in good agreement with previous ones obtained on the same diodes using single photon absorption process.

OBIC technique applied to wide bandgap semiconductors from 100 K up to 450 K

“…Ionization rates vs. inverse of electric field for 4H-SiC using OBIC method with single-and twophoton absorption process, and compared to other authors. Figure 12 displays also ionization rates vs. inverse of the electric field found by many authors [17].…”

“…where An,b and Bn,p are constants to be determined and E is the electric field. OBIC measurements are realized on diodes of structure a, and experimental multiplication curve (inside the optical window) is found by considering V0 = 1 V. Ionization rates parameters are then adjusted to fit theoretical curve of M with experimental one by minimizing an error function DM [15,17]. Table 2 displays the values of An,b and Bn,p for 4H-SiC using both of laser sources (and then single-and two-photon absorption processes).…”

Experimental and simulation results of optical beam induced current technique applied to wide bandgap semiconductors

“…OBIC measurements are realized on Schottky diodes with an optical window. Experimental multiplication curve (inside the optical window) is found by considering V0 = 1 V. Ionization rates parameters are then adjusted to fit theoretical curve of M with experimental one by minimizing an error function DM [15]- [17]. Table 2 displays the values of An,b and Bn,p for 4H-SiC using both of laser sources (and then single-and two-photon absorption processes).…”

“…Green Table 2. Parameters of ionization rates of 4H-SiC using OBIC method with two different wavelengths [15]- [17]. Fig.…”

Investigation of multiphoton photocurrent in SiC using phase-modulated femtosecond laser pulses

“…Furthermore, excellent electron mobility, thermal conductivity, chemical resistance, and breakdown electric field collectively contribute to its stability and efficiency. Similar to GaP, SiC demonstrates characteristics of an indirect bandgap semiconductor and display a multitude of nonlinear phenomenon, including multiphoton absorption (MPA), harmonic generation, and phase modulation, all of which are key to comprehending the functionalities of the optoelectronic device [15][16][17][18][19] .…”