Lifetime Measurement in n-Type 4H-SiC by Mean of the Microwave Phase-Shift

Abstract

During the past years, our team developed an original lifetime measurement method for semiconductors wafers, called microwave phase-shift (µW-PS). It was successfully employed to determinate bulk lifetime and surface recombination velocities on silicon. We recently adapted the method to silicon carbide (SiC), using a continuous UV laser and acousto-optic modulator. The theory is presented, using the standard continuity equation in n-type 4H-SiC. The proposed measurement setup firstly allows to estimate a bulk lifetime ranging from 2.3 to 6.7 µs.

Optimization Strategy of 4H-SiC Separated Absorption Charge and Multiplication Avalanche Photodiode Structure for High Ultraviolet Detection Efficiency

“…The carrier-carrier scattering for the carrier transport process has also been included in low field mobility model. The Shockley-Read-Hall (SRH) recombination lifetime is assumed to 1 μs [24]. Specifically, the field (E) dependence of the impact ionization coefficients for electrons (α n ) and holes (β p ) for 4H-SiC-based layers can be expressed by Chynoweth formulas (1) The absorption coefficient (∂) in terms of different wavelengths (λ) for 4H-SiC material is calculated by the following Eq.…”