scholarly journals Designing a Robust Kelvin Probe Setup Optimized for Long-Term Surface Photovoltage Acquisition

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4068 ◽  
Author(s):  
Elke Beyreuther ◽  
Stefan Grafström ◽  
Lukas Eng
Keyword(s):  
Deep Level ◽  
Surface Photovoltage ◽  
Probe Design ◽  
Relaxation Processes ◽  
Kelvin Probe ◽  
Electrical Stability ◽  
Temperature Dependent ◽  
Transient Spectroscopy ◽  
Photoinduced Charge

We introduce a robust low-budget Kelvin probe design that is optimized for the long-term acquisition of surface photovoltage (SPV) data, especially developed for highly resistive systems, which exhibit—in contrast to conventional semiconductors—very slow photoinduced charge relaxation processes in the range of hours and days. The device provides convenient optical access to the sample, as well as high mechanical and electrical stability due to off-resonance operation, showing a noise band as narrow as 1 mV. Furthermore, the acquisition of temperature-dependent SPV transients necessary for SPV-based deep-level transient spectroscopy becomes easily possible. The performance of the instrument is demonstrated by recording long-term SPV transients of the ultra-slowly relaxing model oxide strontium titanate (SrTiO 3 ) over 20 h.

Improved SiO2/ 4H-SiC Interface Defect Density Using Forming Gas Annealing

2019 ◽  
Vol 963 ◽  
pp. 465-468
Author(s):  
Stephan Wirths ◽  
Giovanni Alfieri ◽  
Alyssa Prasmusinto ◽  
Andrei Mihaila ◽  
Lukas Kranz ◽  
...  
Keyword(s):  
Defect Density ◽  
Deep Level ◽  
Flat Band ◽  
Temperature Dependent ◽  
Mos Capacitors ◽  
Interface Defect ◽  
Before And After ◽  
Oxide Deposition ◽  
Transient Spectroscopy ◽  
Post Deposition

We investigated the influence of forming gas annealing (FGA) before and after oxide deposition on the SiO2/4H-SiC interface defect density (Dit). For MOS capacitors (MOSCAPs) that were processed using FGAs at temperatures above 1050°C, CV characterization revealed decreased flat band voltage shifts and stretch-out for different sweep directions and frequencies. Moreover, constant-capacitance deep level transient spectroscopy (CC-DLTS) was performed and showed Dit levels below 1012 cm-2eV-1 for post deposition FGA at 1200°C. Finally, lateral MOSFETs were fabricated to analyze the temperature-dependent threshold voltage (Vth) shift.

Transport Properties and Conduction Band Offset of n-ZnO/n-6H-SiC Heterostructures

2006 ◽  
Vol 957 ◽  
Author(s):  
Yahya Alivov ◽  
Xiao Bo ◽  
Fan Qian ◽  
Daniel Johnstone ◽  
Cole Litton ◽  
...  
Keyword(s):  
Conduction Band ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Band Offset ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Conduction Band Offset ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Transient Spectroscopy

ABSTRACTThe conduction band offset of n-ZnO/n-6H-SiC heterostructures fabricated by rf-sputtered ZnO on commercial n-type 6H-SiC substrates has been measured. Temperature dependent current-voltage characteristics, photocapacitance, and deep level transient spectroscopy measurements showed the conduction band offsets to be 1.25 eV, 1.1 eV, and 1.22 eV, respectively.

Contact-Related Deep States in AI-GaInP/GaAs Interface

1993 ◽  
Vol 325 ◽  
Author(s):  
Z.C. Huang ◽  
C.R. Wie
Keyword(s):  
Deep Level ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Temperature Dependent ◽  
Current Voltage ◽  
Oxygen Contamination ◽  
Related Defect ◽  
Current Voltage Characteristics ◽  
Transient Spectroscopy ◽  
Recombination Current

AbstractDeep levels have been measured in molecular beam epitaxy grown Ga0.51In0.49P/GaAs heterostructure by double correlation deep level transient spectroscopy. Gold(Au) and Aluminum (Al) metals were used for Schottky contact. A contact-related hole trap with an activation energy of 0.50-0.75eV was observed at the A1/GaInP interface, but not at the Au/GaInP interface. To our knowledge, this contact-related trap has not been reported before. We attribute this trap to the oxygen contamination, or a vacancy-related defect, VIn or VGa. A new electron trap at 0.28eV was also observed in both Au- and Al-Schottky diodes. Its depth profile showed that it is a bulk trap in GaInP epilayer. The temperature dependent current-voltage characteristics (I-V-T) show a large interface recombination current at the GaInP surface due to the Al-contact. Concentration of the interface trap and the magnitude of recombination current are both reduced by a rapid thermal annealing at/or above 450°C after the aluminum deposition.

Deep Defects in Fe-Doped GaN Layers Analysed by Electrical and Photoelectrical Spectroscopic Methods

2003 ◽  
Vol 798 ◽  
Author(s):  
H. Witte ◽  
K. Fluegge ◽  
A. Dadgar ◽  
A. Krtschil ◽  
A. Krost ◽  
...  
Keyword(s):  
Deep Level ◽  
Iron Doping ◽  
Defect Level ◽  
Temperature Dependent ◽  
Organic Vapor ◽  
Sapphire Substrates ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
P Type ◽  
Co Doped

ABSTRACTThe electrical activity of iron in Fe- doped, and in Si and Mg co-doped GaN layers grown on sapphire substrates by metal organic vapor phase epitaxy was studied as shown by temperature dependent Hall Effect (TDH) measurements. In all samples iron doping generates an acceptor defect, which compensates donors in n-type GaN. Furthermore, iron doping causes strong potential inhomogeneities, which decrease the Hall mobility in the layers. To verify, if iron creates only hole traps, defects in n-type Si:Fe and Fe doped samples were investigated. The well known dominant electron traps in n-type GaN at 520 – 550 meV and 480 meV were found by deep level transient spectroscopy and thermal admittance spectroscopy, respectively. A high Fe-doped GaN layer shows a low p-type conductivity dominated by the iron acceptor. An activation energy of EV+ 460 meV was determined by TDH indicating, that the iron acceptor correlates with this defect level.

Effect of NO Annealing on 6H- and 4H-SiC MOS Interface States

2010 ◽  
Vol 645-648 ◽  
pp. 499-502 ◽  
Author(s):  
Alberto F. Basile ◽  
John Rozen ◽  
X.D. Chen ◽  
Sarit Dhar ◽  
John R. Williams ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Deep Level ◽  
Capture Cross ◽  
Temperature Dependent ◽  
Band Energy ◽  
Transient Spectroscopy ◽  
Semiconductor Traps

The electrical properties of the SiC/SiO2 interface resulting from oxidation of the n-type 6H-SiC polytype were studied by hi-lo CV, temperature dependent CV and constant capacitance deep level transient spectroscopy (CCDLTS) techniques. Several trap species differing in energy and capture cross section were identified. A trap distribution at 0.5 eV below the 6H-SiC conduction band energy and a shallower density of states in both the 6H and 4H polytyes are passivated by post-oxidation NO annealing. However, other ultra-shallow and deeper defect distributions remain after nitridation. The latter may originate from semiconductor traps.

Electron Trapping in 4H-SiC MOS Capacitors Fabricated by Sodium-Enhanced Oxidation

2012 ◽  
Vol 717-720 ◽  
pp. 757-760 ◽  
Author(s):  
Alberto F. Basile ◽  
A.C. Ahyi ◽  
L.C. Feldman ◽  
J.R. Williams ◽  
P.M. Mooney
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Electron Trapping ◽  
Stress Tests ◽  
Temperature Dependent ◽  
Mos Capacitors ◽  
Total Electron ◽  
Enhanced Oxidation ◽  
Transient Spectroscopy ◽  
Bias Temperature Stress

The electrical properties of the SiO2/SiC interface fabricated by sodium-enhanced oxidation (SEO) of n-type 4H-SiC were studied by temperature-dependent C-V and constant-capacitance deep level transient spectroscopy (CCDLTS). With the exception of near-interface traps in the SiC epi-layer, which are not present in the SEO samples, the trap species observed in SEO capacitors are the same as those observed in both standard-oxidized and NO-annealed MOS capacitors. Total electron trapping in accumulation is comparable in SEO and NO-annealed capacitors; however, the traps in SEO capacitors are located at the interface whereas tunneling into oxide traps is observed in NO-annealed samples. A series of bias-temperature stress tests show that electron trapping is essentially unchanged when mobile sodium ions are moved toward the interface. The improved mobility attained by this process compared to NO annealing may be due to the absence of near-interface SiC traps in SEO samples.

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