Deep Levels Generated by Ion-Implantation in n- and p-Type 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 365-368 ◽  
Author(s):  
Koutarou Kawahara ◽  
Giovanni Alfieri ◽  
Tsunenobu Kimoto
Keyword(s):  
High Temperature ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
High Temperature Annealing ◽  
Implantation Damage ◽  
Transient Spectroscopy ◽  
P Type ◽  
Two Peaks ◽  
Dlts Spectra

The authors have investigated deep levels in the whole energy range of bandgap of 4H-SiC, which are generated by N+, P+, Al+ implantation, by deep level transient spectroscopy (DLTS). Ne+-implanted samples have been also prepared to investigate the pure implantation damage. In the n-type as-grown material, Z1/2 (Ec – 0.63 eV) and EH6/7 (Ec – 1.6 eV) are dominant deep levels. When the implant dose is low, seven peaks (IN1, IN3 ~ IN6, IN8, IN9) have emerged by implantation and annealing at 1000oC in the DLTS spectra from all n-type samples. After high-temperature annealing at 1700oC, however, most DLTS peaks disappeared, and two peaks, Z1/2 and EH6/7 survive. In the p-type as-grown material, D center (Ev + 0.40 eV) and HK4 (Ev + 1.4 eV) are dominant. When the implant dose is low, two peaks (IP1, IP3) have emerged by implantation and annealing at 1000oC, and four traps IP2, IP4 (Ev + 0.72 eV), IP7 (Ev + 1.3 eV), and IP8 (Ev + 1.4 eV) are dominant after annealing at 1700oC.

Process-Induced Defects in High-Purity GaAs

1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle
Keyword(s):  
High Temperature ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Schottky Contacts ◽  
High Temperature Annealing ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTHigh temperature annealing of Si 3 N4 and SiO2 capped high purity LPE GaAs is shown to result in a reduction in the surface carrier concentration by about an order of magnitude. Au Schottky contacts made on the annealed samples were found to have severely degraded breakdown characteristics. Using deep level transient spectroscopy, deep levels at EC–.58eV, EC–.785eV were detected in the SiO2, capped samples and EC–.62eV, EC–.728eV in the Si3N4 capped Samples while none was detected in the unannealed samples.The electrical degradations are explained in terms of compensation mechanisns and depletion layer recombination-generation currents due to the deep levels.

scholarly journals Aluminum and Electron-Irradiation Induced Deep-Levels In N-Type And P-Type 6H-Sic

1998 ◽  
Vol 510 ◽  
Author(s):  
Min Gong ◽  
C. D. Beling ◽  
S. Fung ◽  
G. Brauer ◽  
H. Wirth ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Heavy Ion ◽  
Deep Levels ◽  
Hole Trap ◽  
Electron Traps ◽  
Transient Spectroscopy ◽  
P Type ◽  
Dlts Spectra

AbstractTwo deep levels, located at Ev+0.26eV and Ec-0.44eV, in Al-implanted n-type samples and one at Ev+0.48eV in p-type samples have been observed by the deep level transient spectroscopy. The level of is identified as the shallower aluminum-acceptor. The 1.7 MeV electron-irradiation, used as a probe to distinguish the implantation induced deep-levels, induces at least six electron traps in the n-SiC and one hole-trap in the p-type material. The peak positions of these deep-levels in DLTS spectra are quite different from those induced by Al-implantation. This result suggests that various damages are formed after heavy ion (Al) and light particle (e) irradiation.

Effects of Thermal Oxidation on Deep Levels Generated by Ion Implantation into n-Type and p-Type 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 651-654 ◽  
Author(s):  
Koutarou Kawahara ◽  
Giovanni Alfieri ◽  
Toru Hiyoshi ◽  
Gerhard Pensl ◽  
Tsunenobu Kimoto
Keyword(s):  
Ion Implantation ◽  
Thermal Oxidation ◽  
Deep Level Transient Spectroscopy ◽  
Low Dose ◽  
Deep Level ◽  
Deep Levels ◽  
High Temperature Annealing ◽  
Bulk Region ◽  
Transient Spectroscopy ◽  
P Type

The authors have investigated effects of thermal oxidation on deep levels in the whole energy range of bandgap of 4H-SiC which are generated by ion implantation, by deep level transient spectroscopy (DLTS). The dominant defects in n-type samples after ion implantation and high-temperature annealing at 1700oC, IN3 (Z1/2: Ec – 0.63 eV) and IN9 (EH6/7: Ec – 1.5 eV) in low-dose-implanted samples, can be remarkably reduced by oxidation at 1150oC. However, in p-type samples, the IP8 (HK4: Ev + 1.4 eV) survives and additional defects, several defects such as IP4 (HK0: Ev + 0.72 eV) appear after thermal oxidation in low-dose-implanted samples. The defects except for the IP8 center can be reduced by subsequent annealing at 1400oC. These phenomena are explained by a model that excess interstitials are generated at the oxidizing interface and diffuse into the bulk region.

Reactive-Ion-Etching Induced Deep Levels Observed in n-Type and p-Type 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 759-762
Author(s):  
Koutarou Kawahara ◽  
Giovanni Alfieri ◽  
Michael Krieger ◽  
Tsunenobu Kimoto
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Reactive Ion Etching ◽  
Deep Levels ◽  
Total Density ◽  
Ion Etching ◽  
Initial Concentration ◽  
Grown Sample ◽  
Transient Spectroscopy ◽  
P Type

In this study, deep levels are investigated, which are introduced by reactive ion etching (RIE) of n-type/p-type 4H-SiC. The capacitance of as-etched p-type SiC is remarkably small due to compensation or deactivation of acceptors. These acceptors can be recovered to the initial concentration of the as-grown sample after annealing at 1000oC. However, various kinds of defects remain at a total density of ~5× 1014 cm-3 in a surface-near region from 0.3 μm to 1.0 μm even after annealing at 1000oC. The following defects are detected by Deep Level Transient Spectroscopy (DLTS): IN2 (EC – 0.35 eV), EN (EC – 1.6 eV), IP1 (EV + 0.35 eV), IP2 (HS1: EV + 0.39 eV), IP4 (HK0: EV + 0.72 eV), IP5 (EV + 0.75 eV), IP7 (EV + 1.3 eV), and EP (EV + 1.4 eV). These defects generated by RIE can be significantly reduced by thermal oxidation and subsequent annealing at 1400oC.

Characterisation of the Subthreshold Damage in MeV Ion Implanted p Si

1998 ◽  
Vol 510 ◽  
Author(s):  
Shabih Fatima ◽  
Jennifer Wong-Leung ◽  
John Fitz Gerald ◽  
C. Jagadish
Keyword(s):  
Point Defects ◽  
Deep Level Transient Spectroscopy ◽  
Damage Evolution ◽  
Peak Concentration ◽  
Deep Level ◽  
Extended Defects ◽  
Transmission Electron ◽  
Transient Spectroscopy ◽  
P Type ◽  
Dlts Spectra

AbstractSubthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for the extended defects. Also the mass dependence on the damage evolution has been observed, where rod-like defects are observed in the case of Si and (rod-like defects and loops) for Ge and Sn despite the fact that peak concentration of vacancies for Ge and Sn are normalized to the peak number of vacancies for Si.

Deep Levels in P-Type 4H-SiC Induced by Low-Energy Electron Irradiation

2013 ◽  
Vol 740-742 ◽  
pp. 373-376 ◽  
Author(s):  
Kazuki Yoshihara ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Low Energy ◽  
Epitaxial Layers ◽  
Before And After ◽  
Low Energy Electron ◽  
Transient Spectroscopy ◽  
P Type

We have characterized deep levels in as-grown and electron irradiated p-type 4H-SiC epitaxial layers by the current deep-level transient spectroscopy (I-DLTS) method. A part of the samples were irradiated with electrons in order to introduce defects. As a result, we found that electron irradiation to p-type 4H-SiC created complex defects including carbon vacancy or interstitial. Moreover, we found that observed deep levels are different between before and after annealing, and thus annealing may change structures of defects.

Deep Levels in As-Grown and Electron-Irradiated P-type 4H-SiC

2006 ◽  
Vol 911 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto
Keyword(s):  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Arrhenius Plot ◽  
Deep Level ◽  
Deep Levels ◽  
Emission Time ◽  
Transient Spectroscopy ◽  
P Type ◽  
Thermal Stability Of

AbstractDeep levels in as-grown and electron-irradiated p-type 4H-SiC have been investigated by deep level transient spectroscopy (DLTS). Three hole traps, namely HK2, HK3, and HK4, could be detected in the temperature range from 350K to 700K. Activation energies of the hole traps were estimated to be 0.84 eV for HK2, 1.27 eV for HK3, and 1.44 eV for HK4 from the Arrhenius plot of emission-time constants assuming temperature-independent capture cross section. By double-correlated DLTS (DDLTS), they were revealed to be donor-like (+/0) traps. The concentrations of HK3 and HK4 centers were clearly increased by low-energy (116 keV) electron irradiation. Based on thermal stability of the HK3 and HK4 centers up to 1350°C and the dependence of HK4 concentration on the electron fluence, they may originate from a complex including defect(s) caused by carbon displacement.

CW Laser Induced Deep Level Defects in Virgin Silicon.

1981 ◽  
Vol 4 ◽  
Author(s):  
A. Chantre ◽  
M. Kechouane ◽  
D. Bois
Keyword(s):  
High Temperature ◽  
Point Defects ◽  
Deep Level Transient Spectroscopy ◽  
Solid Phase ◽  
Deep Level ◽  
Deep Levels ◽  
Cw Laser ◽  
Temperature State ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTDeep Level Transient Spectroscopy has been used to investigate cw laser induced defects in virgin silicon. Two main regimes have been found. In the solid phase regime, two well defined deep levels at Ec−0.19 eV and Ec−0.45 eV are observed. This point defect introduction is proposed to be involved in the degradation of ion-implanted cw laser annealed junctions. The mechanism leading to point defects generation is likely to involve trapping of in–diffused vacancies, quenched–in from the high temperature state. In the slip lines or melt regimes, additionnal deep levels are detected, which are ascribed to dislocations.

Deep Level Transient Spectroscopy Study Of High-Temperature Aluminum Implanted 6H-SiC

1996 ◽  
Vol 442 ◽  
Author(s):  
Yuri A. Stotski ◽  
Igor O. Usov ◽  
Alexander V. Suvorov
Keyword(s):  
High Temperature ◽  
Carrier Concentration ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Epitaxial Layers ◽  
Spectroscopy Study ◽  
Four Levels ◽  
Transient Spectroscopy ◽  
The Relationship

AbstractDeep levels in 6H-SiC wafers implanted with Al+ ions at high-temperature were studied using current deep level transient spectroscopy (iDLTS). Aluminum was implanted at a temperature of 1800 °C with an energy of 40 keV and a dose of 2 × 1016 cm−2 into n-type epitaxial layers with different carrier concentration. Four levels were found, at Ec−0.12, Ec−0.13, Ec−1.06 and Ev+0.35 eV. It was established that modification of the carrier concentration in original ntype 6H-SiC epitaxial layers affects the deep levels concentration. The relationship between the thickness of the space charge region and the relative deep level concentration was considered.

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