IN SITU HALL MEASUREMENTS OF MACROSCOPIC ELECTRICAL PROPERTIES OF CHROMIUM-COVERED Si(111) SURFACES

1999 ◽  
Vol 06 (01) ◽  
pp. 7-12 ◽  
Author(s):  
N. G. GALKIN ◽  
D. L. GOROSHKO ◽  
A. V. KONCHENKO ◽  
V. A. IVANOV ◽  
A. S. GOURALNIK
Keyword(s):  
Electrical Properties ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Epitaxial Films ◽  
Surface Phase ◽  
Sheet Resistivity ◽  
Hall Measurements ◽  
Phase Layers ◽  
Surface Phases

The first in situ Hall measurements of the ordered chromium surface phases on Si(111) substrate and CrSi(111) epitaxial films after their formation are presented. Formation of Si (111)-(1× 1)- Cr (0.1 nm Cr) and Si(111)-[([Formula: see text])/30°]-Cr (0.3 nm Cr) surface phases results in an increase in the sheet resistivity of Si(111)-Cr surface phase samples. The conductivities along the surface phases at these chromium thicknesses are very low. The conductivity decrease is caused by a decrease in the electron mobility in the surface phase layers. Formation of an epitaxial CrSi(111) layer with averaged Hall parameters (hole mobility of 440 cm 2· V -1· s -1, sheet resistivity of 2.2·104 Ω-1 and sheet hole concentration of 0.65·1012 cm -2) has been observed at 1.5–1.8 nm of chromium thickness.

Electrical Transport Properties of Highly Aluminum Doped p-Type 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 249-252 ◽  
Author(s):  
Sylvie Contreras ◽  
Leszek Konczewicz ◽  
Pawel Kwasnicki ◽  
Roxana Arvinte ◽  
Hervé Peyre ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electrical Transport ◽  
Hole Concentration ◽  
Electrical Transport Properties ◽  
Capacitance Voltage ◽  
Experimental Values ◽  
Cv Measurements ◽  
P Type ◽  
Secondary Ion

In the range 80 K-900 K, we have investigated the electrical properties of heavily aluminum in-situ doped, 4H-SiC samples. The temperature dependence of the hole concentration and Hall mobility was analyzed in the model taking into account heavy and light holes. The modelisation parameters were compared with experimental values of Secondary Ion Mass Spectroscopy (SIMS) and Capacitance-Voltage (CV) measurements.

FORMATION OF INTERFACES AND TEMPLATES IN THE Si(111)-Cr SYSTEM

1995 ◽  
Vol 02 (04) ◽  
pp. 439-449 ◽  
Author(s):  
N.I. PLUSNIN ◽  
N.G. GALKIN ◽  
V.G. LIFSHITS ◽  
S.A. LOBACHEV
Keyword(s):  
Room Temperature ◽  
Structural Phase ◽  
High Mobility ◽  
Epitaxial Films ◽  
Semiconductor Film ◽  
Structural Phase Transitions ◽  
Surface Phase ◽  
Surface Phases ◽  
Formation Conditions ◽  
Cr System

The literature data and new data on investigation of the Si(111)-Cr system were systematized to the diagram of structural phase transitions. The ranges on this diagram give the formation conditions of various phases and reflect the mechanism of the Cr/Si (111) and CrSi 2/ Si (111) interface formation during room-temperature Cr deposition following annealing. The proofs of the multilayer surface phase formation and the data about transitions between the multilayer surface phases and bulk silicides during formation of the Cr/Si (111) and CrSi 2/ Si (111) interfaces were presented. The investigation of A- and B-type CrSi 2 templates formation was carried out. It was discovered that nucleation conditions and, in particular, the type of surface phases determine the azimuthal orientation of the epitaxial CrSi 2 islands relative to Si (111) under their nucleation. The A- and B-type CrSi 2 epitaxial films were grown by means of the template technique. The A-type CrSi 2 semiconductor film with low concentration and high mobility of holes was obtained.

Electrical Properties of p-Type In-Situ Doped vs. Al-Implanted 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 401-404 ◽  
Author(s):  
Julien Pernot ◽  
Sylvie Contreras ◽  
Jean Camassel ◽  
Jean-Louis Robert
Keyword(s):  
Relaxation Time ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Hall Mobility ◽  
Hole Concentration ◽  
Detailed Comparison ◽  
Time Approximation ◽  
Relaxation Time Approximation ◽  
P Type

We report a detailed investigation of the electrical properties of p-type 4H-SiC. In the range 100 K-800 K we show that, both, the temperature dependence of the hole concentration and Hall mobility is satisfactorily described using the relaxation time approximation. Performing a detailed comparison of in-situ vs. implantation doping, we evidence an incomplete activation of the dose (about 50 ±10 %) with apparition of a large number of compensating centres in the implanted layers.

Influence of iodine on the electrical properties of magnesium phthalocyanines thin film devices

Open Physics ◽  
2006 ◽  
Vol 4 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Abraham Varghese ◽  
C. Menon
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Electrical Parameters ◽  
Trapping Level ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Limited Conduction ◽  
Thin Film Devices

AbstractThe influence of iodine on the electrical properties of sandwich structures of magnesium phthalocyanine (Mg Pc) thin films with gold and aluminium electrodes has been investigated. The various electrical properties and different electrical parameters of the iodine-doped Mg Pc thin film devices have been estimated and compared with the values of normal Mg Pc devices from the analysis of the current-voltage characteristics. Generally samples showed an asymmetric conductivity both under forward and reverse bias. From our study we found that iodine doped Mg Pc films showed an enhanced electrical conductivity of nearly ten times that of typical Mg Pc. At low voltages the films showed an ohmic conduction with a hole concentration of P0 = 6.34 × 1018 m−3 and hole mobility μ = 9.16 × 10−5 m 2 V−1 s−1, whereas at higher voltage levels the conduction is dominated by space charged limited conduction (SCLC) with a discrete trapping level of 1.33 × 1022 m−3 at 0.63 eV above the valance band edge. The ratio of the free charges to trapped charges (trapping factor) for the doped samples was found to be 1.07 × 10−7. Furthermore the reverse conduction mechanisms have also been investigated. From the current limitations in the reverse condition a strong rectifying behaviour was evident which was attributed to Poole-Frankel emission with a field-lowering coefficient of value 2.24 × 10−5 eV m1/2 V−1/2.

Surface Phases of Metals on Silicon as Material for Surface Engineering

2001 ◽  
Vol 697 ◽  
Author(s):  
Alexander A. Saranin ◽  
Sergey V. Rizhkov ◽  
Dmitriy A. Tsukanov ◽  
Victor G. Lifshits ◽  
Andrey V. Zotov ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electrical Resistance ◽  
Surface Engineering ◽  
High Energy ◽  
Scanning Tunneling ◽  
High Energy Electron ◽  
Tunneling Microscopy ◽  
Surface Phases ◽  
Electrical Resistance Measurements

AbstractTo study structural and transport properties of the surface phases on silicon, a number of adsorbate/silicon systems on Si(100) and Si(111) surfaces has been investigated using scanning tunneling microscopy (STM), reflection-high-energy-electron diffraction (RHEED) and in-situ electrical resistance measurements. Results of investigations of formation and electrical properties of Si-Al, Si-Na, Si-Ag and Si-In surface structure are presented.

In Situ Boron and Aluminum Doping and Their Memory Effects in 4H-SiC Homoepitaxial Layers Grown by Hot-Wall LPCVD

2008 ◽  
Vol 600-603 ◽  
pp. 147-150 ◽  
Author(s):  
Guo Sheng Sun ◽  
Yong Mei Zhao ◽  
Liang Wang ◽  
Lei Wang ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Voltage Drop ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Memory Effects ◽  
Aluminum Concentration ◽  
Pin Diodes ◽  
P Type

The in-situ p-type doping of 4H-SiC grown on off-oriented (0001) 4H-SiC substrates was performed with trimethylaluminum (TMA) and/or diborane (B2H6) as the dopants. The incorporations of Al and B atoms and their memory effects and the electrical properties of p-type 4H-SiC epilayers were characterized by secondary ion mass spectroscopy (SIMS) and Hall effect measurements, respectively. Both Al- and B-doped 4H-SiC epilayers were p-type conduction. It was shown that the profiles of the incorporated boron and aluminum concentration were in agreement with the designed TMA and B2H6 flow rate diagrams. The maximum hole concentration for the Al doped 4H-SiC was 3.52×1020 cm-3 with Hall mobility of about 1 cm2/Vs and resistivity of 1.6~2.2×10-2 Wcm. The heavily boron-doped 4H-SiC samples were also obtained with B2H6 gas flow rate of 5 sccm, yielding values of 0.328 Wcm for resistivity, 5.3×1018 cm-3 for hole carrier concentration, and 7 cm2/Vs for hole mobility. The doping efficiency of Al in SiC is larger than that of B. The memory effects of Al and B were investigated in undoped 4H-SiC by using SIMS measurement after a few run of doped 4H-SiC growth. It was clearly shown that the memory effect of Al is stronger than that of B. It is suggested that p-type 4H-SiC growth should be carried out in a separate reactor, especially for Al doping, in order to avoid the join contamination on the subsequent n-type growth. 4H-SiC PiN diodes were fabricated by using heavily B doped epilayers. Preliminary results of PiN diodes with blocking voltage of 300 V and forward voltage drop of 3.0 V were obtained.

Studies on Sputtered Cu–Zn–Sn–O Precursor to Fabricate Cu2ZnSnS4 Thin Films

2018 ◽  
Vol 73 (10) ◽  
pp. 957-964 ◽  
Author(s):  
Xinxing Liu ◽  
Ruiting Hao ◽  
Qichen Zhao ◽  
Faran Chang ◽  
Yong Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Hole Concentration ◽  
Short Circuit ◽  
Hole Mobility ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Optical And Electrical Properties ◽  
Interfacial Conditions ◽  
Czts Thin Films

AbstractThe Cu2ZnSnS4 (CZTS) thin films were fabricated by sulfurization of radiofrequency magnetron sputtered Cu–Zn–Sn–O (CZTO) precursors. Here, we extend recent works in the field of fabricating CZTO precursors by a new approach sputtering ZnO/Sn/Cu targets. The effects of one-step and two-step annealing processes applied for CZTO precursors on the structure, morphology, optical, and electrical properties were investigated systematically. The preannealing step of fundamental phase formation in the sulfurization process was also discussed. The two-step annealing process was found to affect the composition of element Sn slightly but significantly improved crystallinity, CZTS/Mo interfacial conditions, surface roughness, and electrical properties. The two-step annealed CZTS thin films had excellent optical and electrical properties with an optical band gap of 1.51 eV, a hole concentration of 2.4 × 1017 cm−3, and a hole mobility of 1.97 cm2/(V⋅s). In addition, the CZTS/Mo interface with small grains and voids were significantly improved. CZTS-based solar cell devices were successfully fabricated. The characteristics of current–voltage (J–V) curves indicated that short-circuit currents had a tendency to increase with the improvement of CZTS/Mo interface and surface morphology. As a result, the device based on two-step annealed CZTS thin films exhibited better performance with an open-circuit voltage of 553 mV, short-circuit current of 7.2 mA⋅cm−2, a fill factor of 37.8%, and a conversion efficiency of 1.51%.

Formation and Electric Properties of Disordered Yb Layers on Si(111)7×7 Surface

2003 ◽  
Vol 770 ◽  
Author(s):  
Nickolay G. Galkin ◽  
Dmitrii L. Goroshko ◽  
Alexander S. Gouralnik ◽  
Sergei A. Dotsenko ◽  
Andrei N. Boulatov
Keyword(s):  
Room Temperature ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Growth Stages ◽  
Two Dimensional ◽  
Interface Formation ◽  
Dimensional Growth ◽  
2D And 3D ◽  
Semiconductor Type

AbstractInterface formation in Yb/Si(111) system has been investigated by AES and EELS spectroscopy and in situ Hall measurements at room temperature. It was found that interface formation process may be divided into five stages: 1) two-dimensional growth of Yb, 2) intermixing and formation of two-dimensional Yb silicide, 3) formation of 3D silicide islands, 4) growth of Yb on 3D silicide islands, 5) coalescence of 3D Yb – Yb silicide islands and formation of continuos Yb film. We attribute the observed character of conductivity in Yb/Si(111) system to the evolution of morphological and electrical properties of the growing Yb layer (2D Yb, silicide, metal) rather than to the changes within the space charge layer under the surface. Some amplitude oscillations have been observed in sheet conductivity, hole mobility and surface hole concentration within the coverage range below 6 ML where formation of a continuos Yb silicide film completes. Conductivity oscillations are explained by transition from semiconductor-type conductivity at the first growth stages (two-dimensional Yb growth) to metal-like conductivity of 2D and 3D Yb silicide films.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

Sign in / Sign up

Export Citation Format

Share Document