scholarly journals Impact of invasive metal probes on Hall measurements in semiconductor nanostructures

Nanoscale ◽  
2020 ◽  
Vol 12 (39) ◽  
pp. 20317-20325
Author(s):  
Jan G. Gluschke ◽  
Jakob Seidl ◽  
H. Hoe Tan ◽  
Chennupati Jagadish ◽  
Philippe Caroff ◽  
...  

Experimental data and modelling show that invasive Hall probes lead to substantial misestimates of carrier concentration and mobility in 2D-nanostructure devices.

2014 ◽  
Vol 161 (9) ◽  
pp. B176-B182 ◽  
Author(s):  
E. Prabhu ◽  
K. I. Gnanasekar ◽  
T. R. Ravindran ◽  
V. Jayaraman ◽  
T. Gnanasekaran

Author(s):  
Ho-Ki Lyeo ◽  
C. K. Ken Shih ◽  
Uttam Ghoshal ◽  
Li Shi

There is intense interest to develop nanowires [1] and superlattices [2] that may offer superior thermoelectric figure of merit for efficient energy conversion. Meanwhile, the advance of semiconductor processing techniques has yielded impurity-doped semiconductor nanostructures with a doped region as small as a few nanometers. These include shallow junction Si field-effect transistors, strained Si/SiGe/Ge heterostructures and quantum dots, III-V heterostructures, and doped nanowires and nanotubes. Due to various size confinement effects, these doped semiconductor nanostructures often have unique electrical, optoelectronic, or thermoelectric properties that may lead to a wide range of applications. In contrast to the progress made in synthesizing thermoelectric nanostructures and in fabricating doped semiconductor nanostructures, the ability to quantify thermoelectric property and carrier concentration in comparable length scale has been lagging behind. For example, the 1997 U.S. Roadmap of Semiconductors from the Semiconductor Industry Association (SIA) defines the need for nanometer-scale measurements of carrier concentration profiles [3]. Though progress has been made, currently no technique can satisfy the requirements posted by the SIA roadmap due to the lack of either spatial resolution or accuracy.


2012 ◽  
Vol 717-720 ◽  
pp. 713-716 ◽  
Author(s):  
Sarit Dhar ◽  
Ayayi Claude Ahyi ◽  
John R. Williams ◽  
Sei Hyung Ryu ◽  
Anant K. Agarwal

Hall measurements on NO annealed 4H-SiC MOS gated Hall bars are reported in the temperature range 77 K- 423 K. The results indicate higher carrier concentration and lower trapping at increased temperatures, with a clear strong inversion regime at all temperatures. In stark contrast to Si, the Hall mobility increases with temperature for 77 K-373K, above which the mobility decreases slightly. The maximum experimental mobility was found to be ~50 cm2V-1s-1which is only about 10% of the 4H-SiC bulk mobility indicating that while NO annealing drastically improves trapping, it does not improve the mobility significantly. Supporting modeling results strongly suggest the presence of a disordered SiC channel region.


2019 ◽  
Vol 14 (31) ◽  
pp. 129-137
Author(s):  
Mymana W. Eesa

Cadmium sulfide photodetector was fabricated. The CdS nanopowder has been prepared by a chemical method and deposited as athin film on both silicon and porous p- type silicon substrates by spincoating technique. Structural, morphological, optical and electricalproperties of the prepared CdS nano powder are studied. The X-rayanalysis shows that the obtained powder is CdS with predominantlyhexagonal phase. The Hall measurements show that the nano powderis n-type with carrier concentration of about (-5.4×1010) cm-3. Theresponse time of fabricated detector was measured by illuminatingthe sample with visible radiation and its value was 5.25 msec. Thespecific detectivity of the fabricated detector is found to be (9×1011W-1 .Hz1/2.Cm- 1). The responsivity was (0.03A/W).


1997 ◽  
Vol 482 ◽  
Author(s):  
Richard T. Webster ◽  
A. F. M. Anwar

AbstractCalculated sheet carrier concentration as a function of Al mole fraction in the quantum well (QW) formed at the GaN/AlGaN heterointerface is calculated and compared to experimental data. Close agreement between experiment and theory is observed. The calculated sheet carrier concentration reflects the maximum carrier concentration possible in the GaN QW for a given Al mole fraction and can not be used to argue in favor of either interface charge or piezoelectric effect as giving rise to the carriers. Based on experimental data the charge density in the AlGaN layer is estimated to be 4 × 1012cm-2The calculations are based upon a simple technique to determine valence band alignments. Calculated values are compared to experimental data showing excellent agreement. A calculated valence band discontinuity of 0.42eV for AlN/GaN is well within the experimental bounds.


2017 ◽  
Vol 121 (23) ◽  
pp. 234304 ◽  
Author(s):  
R. Raciti ◽  
R. Bahariqushchi ◽  
C. Summonte ◽  
A. Aydinli ◽  
A. Terrasi ◽  
...  

2003 ◽  
Vol 799 ◽  
Author(s):  
James E. Maslar ◽  
Wilbur S. Hurst ◽  
Christine A. Wang ◽  
Daniel A. Shiau

ABSTRACTGaSb-based semiconductors are of interest for mid-infrared optoelectronic and high-speed electronic devices. Accurate determination of electrical properties is essential for optimizing the performance of these devices. However, electrical characterization of these semiconductors is not straightforward since semi-insulating (SI) GaSb substrates for Hall measurements are not available. In this work, the capability of Raman spectroscopy for determination of the majority carrier concentration in n-GaInAsSb epilayers was investigated. Raman spectroscopy offers the advantage of being non-contact and spatially resolved. Furthermore, the type of substrate used for the epilayer does not affect the measurement. However, for antimonide-based materials, traditionally employed Raman laser sources and detectors are not optimized for the analysis wavelength range dictated by the narrow band gap of these materials. Therefore, a near-infrared Raman spectroscopic system, optimized for antimonide-based materials, was developed.Ga0.85In0.15As0.13Sb0.87 epilayers were grown by organometallic vapor phase epitaxy with doping levels in the range 2 to 80 × 1017 cm-3, as measured by secondary ion mass spectrometry. For a particular nominal doping level, epilayers were grown both lattice matched to n-GaSb substrates and lattice-mismatched to SI GaAs substrates under nominally identical conditions. Single magnetic field Hall measurements were performed on the epilayers grown on SI GaAs substrates, while Raman spectroscopy was used to measure the carrier concentration of epilayers grown on GaSb and the corresponding SI GaAs substrates. Contrary to Hall measurements, Raman spectra indicated that the GaInAsSb epilayers grown on GaSb substrates have higher free carrier concentrations than the corresponding epilayers grown on SI GaAs substrates under nominally identical conditions. This is contrary to the assumption that for nominally identical growth conditions, the resulting carrier concentration is independent of substrate, and possible mechanisms will be discussed.


1989 ◽  
Vol 163 ◽  
Author(s):  
Tae-Yeon Seong ◽  
A.G. Norman ◽  
G.R. Booker ◽  
R. Droopad ◽  
R.L. Williams ◽  
...  

AbstractMBE InASySb1-y layers were grown at 370°C across the full composition range. TEM/TED examinations directly showed that separation into two phases had taken place for compositions 0.4<y<0.8 with plates 20 to 200nm thick occurring approximately parallel to the layer surface. The two phases in the individual specimens were tetragonally distorted and their compositions were deduced from the TED results. CuPt-type atomic ordering occurred and was most pronounced in the middle of the composition range. Alloy clustering was also present. Hall measurements showed that the carrier concentration was a maximum, and the mobility was a minimum, for the middle of the composition range.


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