Compensation mechanism in high purity semi-insulating 4H-SiC

Abstract

Defect levels and types of point defects in high-purity and vanadium-doped semi-insulating 4H-SiC J. Appl. Phys. 96, 5484 (2004); 10.1063/1.1797547 Fermi level control and deep levels in semi-insulating 4H-SiCA study of deep levels in high purity semi-insulating 4H-SiC has been made using temperature dependent Hall effect ͑TDH͒, thermal and optical admittance spectroscopies, and secondary ion mass spectrometry ͑SIMS͒. Thermal activation energies from TDH varied from a low of 0.55 eV to a high of 1.65 eV. All samples studied showed n-type conduction with the Fermi level in the upper half of the band gap. Fits of the TDH data to different charge balance equations and comparison of the fitting results with SIMS measurements indicated that the deep levels are acceptorlike even though they are in the upper half of the band gap. Carrier concentration measurements indicated that the deep levels are present in concentrations in the low 10 15 cm −3 range, while SIMS results demonstrate nitrogen and boron concentrations in the low to mid-10 15 -cm −3 range. The results suggest that compensation in this material is a complex process involving multiple deep levels.

High-voltage lateral double-implanted MOSFETs implemented on high-purity semi-insulating 4H-SiC substrates with gate field plates

“…The relatively lower breakdown field in our simulation work than the reported values results from the extremely low carrier concentration in semi-insulating SiC substrates without any intentional doping. 25,26) In the case of L drift = 5 µm, the depletion expanded from the p-well and reached the drain junction before breakdown. However, the others show non-punch-through behavior at a given doping concentration of the drift region (n drift = 8 × 10 16 cm −3 ).…”

Vanadium doping using VCl4 source during the chloro-carbon epitaxial growth of 4H-SiC

“…In the high-purity semiinsulating (HPSI) SiC materials grown by high-temperature chemical vapor deposition (HTCVD) [10,11] and PVT [12,13], the compensation of shallow donor and acceptor levels was achieved by intrinsic deep-level defects. However, the exact nature of the intrinsic defects involved in the compensation mechanisms is still under investigation [5,17].…”

Photosensitive Capacitance Effect In High-purity Semi-insulating 4H-SiC

“…As such, the Z 1 /Z 2 trap center is a combination defect and has similar equal cross section for electrons and holes (10 -14 cm 2 ) making it an efficient recombination center [7]. The DLTS technique requires assumptions to be made about the temperature dependence of the capture cross section parameter of each defect and therefore the defect positions often very in the literature making the true parameters of the effect under investigation difficult to model [8].…”