Impact of carbon injection in 4H-SiC on defect formation and minority carrier lifetime

• DOI: 10.1016/j.mssp.2024.108316
• Publication Date: 2024-03-11T23:13:47Z
• Authors: Marianne Etzelmül...; Robert Karsthof; Augustinas Galeckas; Piyush Kumar; Andrej Yu. Kuznetsov; Ulrike Grossner; Lasse Vines
• Keywords: Deep-level transient spectroscopy; Carrier lifetime; Carbon fibers

Point defects in silicon carbide (SiC) can act as charge carrier traps and have a pronounced impact on material properties such the mobility lifetime. Prominent among these is carbon vacancy (VC) with demonstrated detrimental effect minority lifetime 4H-SiC epitaxial layers. Hence, variety of methods for VC removal been proposed. Common to all that they involve some sort C-injection into epi-layer leads annihilation C interstitials (Ci) via reaction Ci+ →0̸. However, many studies injection Ci do not take account potential any additional are formed result excess material, including electrically active introduce energy levels SiC band gap. Herein, we study formation related introduced epi-layers by carbon. achieved annealing covered graphitized photoresist known C-cap at 1250 °C different durations. The resulting appearance samples monitored using deep level transient spectroscopy (DLTS) (MCTS) measurements, which reveal both majority C-injection. Intriguingly, injected also found interact perennially present impurity potentially limiting defect, namely boron. Furthermore, monitor function time depth from surface cross-sectional time-resolved photoluminescence (TRPL) measurements. Both defect distributions depend strongly duration anneal, marked dependence being studied. moderate temperature treatment proposed method enhancing n-type power device applications.