A Comparison of Free Carrier Absorption and Capacitance Voltage Methods for Interface Trap Measurements

Sethu Saveda Suvanam; M. Usman; K. Gulbinas; V. Grivickas; Anders Hallén

doi:10.4028/www.scientific.net/MSF.740-742.465

Paper Titles

The Formation of New Periodicities after N-Implantation in 4H- and 6H-SiC Samples
p.447

The Integrated Evaluation Platform for SiC Wafers and Epitaxial Films
p.451

Theoretical Study of N Incorporation Effect during SiC Oxidation
p.455

To the Experimental Determination of the Spontaneous Polarization for the Silicon Carbide Polytypes
p.459

A Comparison of Free Carrier Absorption and Capacitance Voltage Methods for Interface Trap Measurements
p.465

A New-Type of Defect Generation at a 4H-SiC/SiO₂Interface by Oxidation Induced Compressive Strain
p.469

Characterization of the Metal-Semiconductor Interface of Pt-GaN Diode Hydrogen Sensors
p.473

Deep-Level-Transient Spectroscopy Characterization of Mobility-Limiting Traps in SiO₂/SiC Interfaces on C-Face 4H-SiC
p.477

Dislocation Analysis of 4H-/6H-SiC Single Crystals Using Micro-Raman Spectroscopy
p.481

HomeMaterials Science ForumMaterials Science Forum Vols. 740-742A Comparison of Free Carrier Absorption and...

A Comparison of Free Carrier Absorption and Capacitance Voltage Methods for Interface Trap Measurements

Abstract:

This paper aims to establish a new method to characterize the interface between 4H-SiC and passivating dielectric layers. The investigations are made on MOS test structures utilizing Al₂O₃ and SiO₂ dielectrics on 4H-SiC. These devices are then exposed to various fluences of Ar⁺ implantation and then measured by the new method utilizing optical free carrier absorption (FCA) technique to assess the interface traps. A program has been developed using MATLAB to extract surface recombination velocity (SRV) at the oxide/epi-layer interface from the optical data. Capacitance-voltage (CV) is done to extract the density of interface traps (D_it) and a comparison was made. It is observed that SiO₂ samples show a large rise of SRVs, from 0.5×10⁴ cm/s for a reference sample to 8×10⁴ cm/s for a fluence of 1×10^₁₂ cm^-2, whereas Al₂O₃ samples show more stable SRV, changing from 3×10⁴ cm/s for the un-irradiated reference sample to 6×10⁴ cm/s for a fluence of 1×10¹² cm^-2. A very similar trend is observed for D_it values extracted from CV measurements and it can therefore be concluded that the FCA method is a suitable technique for the interface characterization.