Impacts of reduction of deep levels and surface passivation on carrier lifetimes in p-type 4H-SiC epilayers

Abstract

Temperature dependent recombination dynamics in InP/ZnS colloidal nanocrystals Appl. Phys. Lett. 101, 091910 (2012) Intrinsic defect in BiNbO4: A density functional theory study J. Appl. Phys. 112, 043706 (2012) The CuInSe2-CuIn3Se5 defect compound interface: Electronic structure and band alignment Appl. Phys. Lett. 101, 062108 (2012) Investigation of deep-level defects in conductive polymer on n-type 4H-and 6H-silicon carbide substrates using I-V and deep level transient spectroscopy techniques Impacts of reduction of deep levels and surface passivation on carrier lifetimes in p-type 4H-SiC epilayers are investigated. The authors reported that the carrier lifetime in n-type epilayers increased by reduction of deep levels through thermal oxidation and thermal annealing. However, the carrier lifetimes in p-type epilayers were not significantly enhanced. In this study, in order to investigate the influence of surface passivation on the carrier lifetimes, the epilayer surface was passivated by different oxidation techniques. While the improvement of the carrier lifetime in n-type epilayers was small, the carrier lifetime in p-type epilayers were remarkably improved by appropriate surface passivation. For instance, the carrier lifetime was improved from 1.4 ls to 2.6 ls by passivation with deposited SiO 2 annealed in NO. From these results, it was revealed that surface recombination is a limiting factor of carrier lifetimes in p-type 4H-SiC epilayers.

Enhancement and control of carrier lifetimes in p-type 4H-SiC epilayers

“…The surface recombination velocity on p-type 4H-SiC, however, may be still high. 39 The distribution of surface state density must be different near the conduction and valence bands. In addition, the direction of surface band bending is opposite, and the position of the surface Fermi level must be different for n-and p-type epilayers.…”

Observation of deep levels and their hole capture behavior in p-type 4H-SiC epilayers with and without electron irradiation

“…Silicon carbide (SiC) bipolar devices are considered as candidates of such power devices [1]. p-type SiC is a key material for development of bipolar SiC devices, and for any bipolar devices, control of the carrier lifetime in epilayers is strongly important [2][3][4][5]. However, studies for deep levels which affect the carrier lifetime in p-type 4H-SiC have been rarely reported.…”

Photoluminescence Quantum Yield of Fluorescent Silicon Carbide Determined by an Integrating Sphere Setup

“…We believe that this phenomenon is caused by the enhanced Auger recombination in the f-SiC sample when the incident power density on the sample is increased. 29 In particular, it has been observed that 30 a fast decay component emerges during free carrier absorption (FCA) measurement on SiC at elevated injection levels, where this fast decay channel is attributed to band-to-band Auger recombination. Moreover, it is well known that the rate of Auger recombination is proportional to the cube 31 of the total carrier densities, i.e., n 0 + Δ n , where Δ n refers to the density of nonequilibrium carriers.…”