Midgap Levels in As-Grown 4H-SiC Epilayers Investigated by DLTS

2005 ◽  
Vol 483-485 ◽  
pp. 355-358 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto ◽  
Hiroyuki Matsunami
Keyword(s):  
Electric Fields ◽  
Electron Emission ◽  
Minority Carrier ◽  
Deep Level ◽  
Deep Trap ◽  
Dlts Spectrum ◽  
Carrier Traps ◽  
P Type ◽  
Two Peaks ◽  
Dlts Spectra

Midgap levels in 4H-SiC epilayers have been investigated by DLTS. The EH6/7 center (Ec-1.55 eV) is the dominant deep level as observed in DLTS spectra from n-type epilayers. The activation energy of EH6/7 center is unchanged regardless of applied electric fields, indicating that the charge state of EH6/7 center may be neutral after electron emission (acceptor-like). A DLTS spectrum for a p-type epilayer in the temperature range from 90 to 830 K is dominated by two peaks, D center and a deep trap at 1.49 eV from the valence band edge. Minority carrier traps have been also investigated by DLTS using pn diodes. Two minority carrier traps with activation energies of 1.0 eV and 1.43 eV have been detected.

C-V and DLTS Analyses of Trap-Induced Graded Junctions: The Case of Al+ Implanted JTE p+n 4H-SiC Diodes

2009 ◽  
Vol 615-617 ◽  
pp. 469-472
Author(s):  
Filippo Fabbri ◽  
Francesco Moscatelli ◽  
Antonella Poggi ◽  
Roberta Nipoti ◽  
Anna Cavallini
Keyword(s):  
Depth Distribution ◽  
Minority Carrier ◽  
Deep Level ◽  
Forward Bias ◽  
Depth Range ◽  
Standard Configuration ◽  
Carrier Traps ◽  
Transient Spectroscopy ◽  
Graded Junction ◽  
Dlts Spectra

Capacitance versus Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) measurements of Al+ implanted p+n diodes with Al+ implanted Junction Termination Extension are here studied. These diodes present C-V characteristics like graded junction for low forward bias values, i.e. > 0.4 V , or like abrupt junctions for large reverse bias, i.e. between 0.4V and -10V. The depth range of the graded junction, computed by the capacitance values, is much larger than the simulated tail of the ion implanted Al+ profile. DLTS spectra have been measured both in injection and standard configuration and always show minority carrier traps in the temperature range 0-300K. Three are the minority carrier related peaks, one attributed to the Al acceptor and the others to the D and D1 defects. The depth distribution of these hole traps will be discussed with respect to the apparent carrier concentration, obtained by C-V analysis.

Investigating Minority-Carrier Traps in p-type Cu(InGa)Se2 Using Deep Level Transient Spectroscopy

2005 ◽  
Vol 865 ◽  
Author(s):  
Steven W. Johnston ◽  
Jehad A. M. AbuShama ◽  
Rommel Noufi
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Thermionic Emission ◽  
Small Peak ◽  
Carrier Traps ◽  
Transient Spectroscopy ◽  
Lower Temperature ◽  
And Shifts ◽  
P Type

AbstractMeasurements of p-type Cu(InGa)Se2 (CIGS) using deep-level transient spectroscopy (DLTS) show peaks associated with minority-carrier traps, even though data were collected using reverse bias conditions not favorable to injecting minority-carrier electrons. These DLTS peaks occur in the temperature range of 50 to 150 K for the rate windows used and correspond to electron traps having activation energies usually in the range of 0.1 to 0.2 eV for alloys of CIS, CGS, and CIGS. The peak values also depend on the number of traps filled. For short filling times of 10 μs to 100 μs, a small peak appears. As the DLTS filling pulse width increases, the peak increases in response to more traps being filled, but it also broadens and shifts to lower temperature suggesting that a possible series of trap levels, perhaps forming a defect band, are present. The peaks usually saturate in a timeframe of seconds. These filling times are sufficient for electrons to fill traps near the interface from the n-type side of the device due to a thermionic emission current. Admittance spectroscopy data for the same samples are shown for comparison.

scholarly journals Characterization of a Dominant Electron Trap in GaNAs Using Deep-Level Transient Spectroscopy

2005 ◽  
Vol 891 ◽  
Author(s):  
Steven W. Johnston ◽  
Sarah R. Kurtz ◽  
Richard S. Crandall
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Chemical Vapor ◽  
Electron Trap ◽  
Organic Chemical ◽  
Conduction Band Offset ◽  
Carrier Traps ◽  
Transient Spectroscopy ◽  
P Type

ABSTRACTDilute-nitrogen GaNAs epitaxial layers grown by metal-organic chemical vapor deposition were characterized by deep-level transient spectroscopy (DLTS). For all samples, the dominant DLTS signal corresponds to an electron trap having an activation energy of about 0.25 to 0.35 eV. The minority-carrier trap density in the p-type material is quantified based on computer simulation of the devices. The simulations show that only about 2% of the traps in the depleted layer are filled during the transient. The fraction of the traps that are filled depends strongly on the depth of the trap, but only weakly on the doping of the layers and on the conduction-band offset. The simulations provide a pathway to obtain semi-quantitative data for analysis of minority-carrier traps by DLTS.

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.

Detection of minority carrier traps in p-type 4H-SiC

2014 ◽  
Vol 104 (9) ◽  
pp. 092105 ◽  
Author(s):  
G. Alfieri ◽  
T. Kimoto
Keyword(s):  
Minority Carrier ◽  
Carrier Traps ◽  
P Type

Characterization of Traps in GaN pn Junctions Grown by MOCVD on GaN Substrate Using Deep-Level Transient Spectroscopy

2008 ◽  
Vol 600-603 ◽  
pp. 1297-1300 ◽  
Author(s):  
Yutaka Tokuda ◽  
Youichi Matsuoka ◽  
Hiroyuki Ueda ◽  
Osamu Ishiguro ◽  
Narumasa Soejima ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Electron Traps ◽  
Majority Carrier ◽  
Sapphire Substrates ◽  
Carrier Traps ◽  
Pn Junctions ◽  
Transient Spectroscopy

Minority- and majority-carrier traps were studied in GaN pn junctions grown homoepitaxially by MOCVD on n+ GaN substrates. Two majority-carrier traps (MA1,MA2) and three minority-carrier traps (MI1, MI2, MI3) were detected by deep-level transient spectroscopy. MA1 and MA2 are electron traps commonly observed in n GaN on n+ GaN and sapphire substrates. No dislocation-related traps were observed in n GaN on n+ GaN. Among five traps in GaN pn on GaN, MI3 is the main trap with the concentration of 2.5x1015 cm-3.

Impact of the Gate Material on the Deep Levels in a-Si:H/c-Si Metal-Insulator-Semiconductor Capacitors

2015 ◽  
Vol 242 ◽  
pp. 61-66
Author(s):  
Eddy Simoen ◽  
Valentina Ferro ◽  
Barry O’Sullivan
Keyword(s):  
Minority Carrier ◽  
Crystalline Silicon ◽  
Deep Level ◽  
Silicon Layer ◽  
Si Substrate ◽  
Metal Insulator ◽  
Metal Insulator Semiconductor ◽  
Transient Spectroscopy ◽  
P Type ◽  
Mis Capacitors

Deep Level Transient Spectroscopy (DLTS) has been applied to Metal-Insulator-Semiconductor (MIS) capacitors, consisting of a p+ or n+ a-Si:H gate on an intrinsic i-a-Si:H passivation layer deposited on crystalline silicon n-or p-type substrates. It is shown that the type of gate has a pronounced impact on the obtained spectra, whereby both the kind of defects (dangling bonds at the a-Si:H/(100) c-Si interface (Pb0 defects) or in the amorphous silicon layer (D defects) and their relative importance (peak amplitude) may be varied. The highest trap densities have been found for the p+ a-Si:H gate capacitors on an n-type Si substrate. In addition, the spectra may exhibit unexpected negative peaks, suggesting minority carrier capture. These features are tentatively associated with interface states at the p+ or n+ a-Si:H/i-a-Si:H interface. Their absence in Al-gate capacitors is in support of this hypothesis.

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.

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