Defects and carrier compensation in semi-insulating<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>4</mml:mn><mml:mi>H</mml:mi><mml:mtext>−</mml:mtext><mml:mi mathvariant="normal">Si</mml:mi><mml:mi mathvariant="normal">C</mml:mi></mml:mrow></mml:math>substrates

Són, Nguyên Tiên; Carlsson, Patrick; Ul-Hassan, Jawad; Magnusson, Björn; Janzén, Erik

doi:10.1103/physrevb.75.155204

Cited by 120 publications

(164 citation statements)

References 26 publications

Supporting

Mentioning

142

Contrasting

Order By: Relevance

“…[27][28][29] The V + C center is a common defect in high-purity semi-insulating (HPSI) SiC substrates [30][31][32][33] and is suggested to be related to the EH 6/7 center. 29,34 The V C defect has been used for controlling the resistivity in commercial HPSI SiC substrates, 35,36 although the detailed mechanism of carrier compensation involving the C vacancy is still not clear. Among different intrinsic defects, V C and the divacancy have been suggested to be the most suitable defects for obtaining thermally stable semi-insulating properties in HPSI SiC substrates.…”

Section: Introductionmentioning

confidence: 99%

Negative-Ucarbon vacancy in 4H-SiC: Assessment of charge correction schemes and identification of the negative carbon vacancy at the quasicubic site

et al. 2013

Self Cite

View full text Add to dashboard Cite

The carbon vacancy (V C ) has been suggested by different studies to be involved in the Z 1 /Z 2 defect-a carrier lifetime killer in SiC. However, the correlation between the Z 1 /Z 2 deep level with V C is not possible since only the negative carbon vacancy (V − C ) at the hexagonal site, V − C (h), with unclear negative-U behaviors was identified by electron paramagnetic resonance (EPR). Using freestanding n-type 4H -SiC epilayers irradiated with low energy (250 keV) electrons at room temperature to introduce mainly V C and defects in the C sublattice, we observed the strong EPR signals of V − C (h) and another S = 1/2 center. Electron paramagnetic resonance experiments show a negative-U behavior of the two centers and their similar symmetry lowering from C 3v to C 1h at low temperatures. Comparing the 29 Si and 13 C ligand hyperfine constants observed by EPR and first principles calculations, the new center is identified as V − C (k). The negative-U behavior is further confirmed by large scale density functional theory supercell calculations using different charge correction schemes. The results support the identification of the lifetime limiting Z 1 /Z 2 defect to be related to acceptor states of the carbon vacancy.

show abstract

Section: Introductionmentioning

confidence: 99%

Negative-Ucarbon vacancy in 4H-SiC: Assessment of charge correction schemes and identification of the negative carbon vacancy at the quasicubic site

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Intrinsic defects such as vacancies (V Si and V C ) 2,3 and their associated complexes (e.g., divacancy 4 and vacancy-antisite pairs 5 ) are also known to be commonly present in as-grown materials and are highly thermally stable. 6 It has been shown that TMs of column IVB, VB, and VIB like Ti, V, Cr (3d elements), Mo (4d), Ta, and W (5d) introduce deep levels in the band gap of 4H-and 6H-SiC. 7 The development of device applications requires defect control in SiC in order to achieve highquality semi-insulating substrates for high-frequency electronics, to improve the carrier lifetime of epitaxial layers and carrier mobility in power devices.…”

Section: Nbmentioning

confidence: 99%

Electron paramagnetic resonance and theoretical studies of Nb in 4H- and 6H-SiC

Són¹,

Trinh²,

Gällström³

et al. 2012

Journal of Applied Physics

View full text Add to dashboard Cite

High purity silicon carbide (SiC) materials are of interest from high-power high temperature applications across recent photo-voltaic cells to hosting solid state quantum bits, where the tight control of electrically, optically, and magnetically active point defects is pivotal in these areas. 4H-and 6H-SiC substrates are grown at high temperatures and the incorporation of transition metal impurities is common. In unintentionally Nb-doped 4H-and 6H-SiC substrates grown by high-temperature chemical vapor deposition, an electron paramagnetic resonance (EPR) spectrum with C 1h symmetry and a clear hyperfine (hf) structure consisting of ten equal intensity hf lines was observed. The hf structure can be identified as due to the interaction between the electron spin S ¼ 1/2 and the nuclear spin of 93 Nb. Additional hf structures due to the interaction with three Si neighbors were also detected. In 4H-SiC, a considerable spin density of $37.4% was found on three Si neighbors, suggesting the defect to be a complex between Nb and a nearby carbon vacancy (V C ). Calculations of the , support previous reported results that Nb preferentially forms an asymmetric split-vacancy (ASV) defect. In both 4H-and 6H-SiC, only one Nb-related EPR spectrum has been observed, supporting the prediction from calculations that the hexagonal-hexagonal defect configuration of the ASV complex is more stable than others. V C 2012 American Institute of Physics. [http://dx

show abstract

“…V C is frequently detected by EPR in high-purity semi-insulating substrates and is believed to play an important role in carrier compensation [10]. It has been shown from deep-level transient spectroscopy (DLTS) that the two most common and unavoidable defect levels in as-grown 4H-SiC layers grown by chemical vapor deposition (CVD) are the Z 1=2 level [11] at $0:56-0:71 eV below the conduction band minimum E C and the EH 6=7 level at $E C À ð1:55-1:65Þ eV [12,13].…”

mentioning

confidence: 99%