Directly Confirming the Z_1/2 Center as the Electron Trap in SiC Through Accessing the Nonradiative Recombination

Abstract

SiC is an important wide‐bandgap semiconductor for high‐power electronics and high‐temperature applications. Its Z 1/2 center, recognized as a carrier lifetime killer, has been extensively studied as it is a key issue impeding many applications of SiC. It is well established that the Z 1/2 center originates from carbon vacancies (VC), but direct access to the microscopic mechanism underlying its nonradiative recombination process is lacking. Herein, to consolidate such identification, the multiphonon‐assisted nonradiative recombination rates of previously proposed different candidates of the Z 1/2 center are evaluated by performing first‐principles calculations. The calculated electron transition cross sections of the VC ( σ normaln = 2.5 × 10 − 15 cm 2 at the k‐site and σ normaln = 3.4 × 10 − 15 cm 2 at the h‐site) are in accordance with the experimental values [from σ normaln = 3.0 × 10 − 15 cm 2 to σ normaln = 1.0 × 10 − 14 cm 2 ] for the Z 1/2 center. However, all of the other candidates are orders of magnitudes smaller in transition cross sections. This provides further evidence that the carbon vacancy (VC) is the Z 1/2 center from the electron transition cross sections. However, it is also found that the hole transition cross sections of the VC are very small. Various hypotheses are provided to consolidate this fact with the conclusion that Z 1/2 is the carrier lifetime killer.

Antisite Defect SiC as a Source of the DI Center in 4H‐SiC

“…[16] However, by first-principles calculations, Gu and Magnusson et al proposed that the transition levels of the inequivalent V C -V Si defects range from 1.1 to 1.75 eV, which are far from the experimental value of D I center (0.35 eV). [17,18] Zhang et al proposed that in silicon-rich growth samples, D I defect concentration decreased with the increase of the C/Si ratio. [7] Many works attributed the D I center to the antisite pair (Si C -C Si ).…”

Clarifying the atomic origin of electron killers in β-Ga2O3 from the first-principles study of electron capture rates

“…Monoclinic gallium sesquioxide ( -Ga 2 O 3 ) has drawn a lot of attention due to its ultra-wide bandgap (~4.9 eV) and ultra-high breakdown electrical fields, which make it promising in the application of power electronics and deep-ultraviolet optoelectronics [1,2] . In particular, it owns a high Baliga's figure of merit more than four times that of GaN and SiC [1] , making it to be an excellent candidate for power semiconductor devices operating in high-frequency circuits [1,2] .…”

“…Monoclinic gallium sesquioxide ( -Ga 2 O 3 ) has drawn a lot of attention due to its ultra-wide bandgap (~4.9 eV) and ultra-high breakdown electrical fields, which make it promising in the application of power electronics and deep-ultraviolet optoelectronics [1,2] . In particular, it owns a high Baliga's figure of merit more than four times that of GaN and SiC [1] , making it to be an excellent candidate for power semiconductor devices operating in high-frequency circuits [1,2] . Besides, the -Ga 2 O 3 devices have the advantages of high radiation hardness, high-temperature stability, potentially low cost due to the earth-abundant material, and ease to manufacture massively due to its compatibility with Si microelectronic technology.…”