Analysis of carrier lifetimes in N + B-doped n-type 4H-SiC epilayers

Abstract

Control of carrier lifetimes in nitrogen (N)-doped n-type 4H-SiC epilayers was attempted by intentional boron (B) doping. Doping concentrations of B were controlled to be within 1015–1018 cm−3 by varying the triethyl boron flow rate during epitaxial growth. Time-resolved photoluminescence measurements for the band edge luminescence of the N + B-doped epilayer showed a fast decay time of less than 30 ns under a low injection level at 300 K, while a slow decay component was observed at elevated temperatures of 423–523 K. To understand the mechanism of carrier capture and recombination in N + B-doped 4H-SiC, excess carrier decay curves were simulated by solving rate equations with a simple model. As an effective “recombination enhancing layer,” the 1.6-μm-thick N + B-doped (N: 4 × 1018 cm−3, B: 7 × 1017 cm−3) buffer layer in the PiN diode showed increased intensity of D center-related electroluminescence with increasing injected hole concentrations and prevented the formation of stacking faults from basal plane dislocations in the substrate even at the injection level of 1 × 1016 cm−3 at the interface between the drift and buffer layers.

4H-SiC Schottky Barrier Diodes as Radiation Detectors: A Review

“…For comparison, some of the physical parameters for SiC polytypes are given in Table 1. Due to the high and isotropic mobility of charge carriers, the 4H polytype of SiC is preferred as a material for power electronics [1], bipolar devices [2], and quantum sensing [3]. Moreover, 4H-SiC has attracted considerable interest in recent years as a very promising material for radiation detection in harsh environments where detectors are exposed to high temperatures and high fluencies of radiation [1,4,5].…”

Depth Profile Analysis of Deep Level Defects in 4H-SiC Introduced by Radiation

“…A long spin-coherence time at room temperature was observed for isolated single-point defects in ion-implanted SiC such as silicon vacancy (V Si ), di-vacancy, and a carbon anti-site defect [6][7][8]. Defect engineering is also used for local carrier lifetime control necessary for the optimization of the switching loss of 4H-SiC power bipolar junction transistors [9] and elimination of the bipolar degradation [10]. In recent years, 4H-SiC radiation detectors have attracted attention due to their high radiation hardness and high signal to noise ratio [11][12][13].…”

Majority and Minority Charge Carrier Traps in n-type 4H-SiC Studied by Junction Spectroscopy Techniques

“…Boron is introduced in SiC intentionaly for p-type doping, or unintentionaly during the crystal growth. The unintentional boron incorporation was recently explained by the presence of boron in the graphite susceptor used for the CVD growth [30][31]. The B and D-centre have been reported in numerous studies and have been assigned to substitutional boron atoms occupying the Si and C-site, respectively [30][31][32][33].…”

“…The unintentional boron incorporation was recently explained by the presence of boron in the graphite susceptor used for the CVD growth [30][31]. The B and D-centre have been reported in numerous studies and have been assigned to substitutional boron atoms occupying the Si and C-site, respectively [30][31][32][33]. The shallow state, BSi is off-center substitutional boron at Si-site, while for the deep state Bc, boron occupies a perfect substitutional C site [34].…”