Influence of Interface States on Output Characteristics of 4H-SiC MESFETs on Semi–Insulating Substrates

2000 ◽  
Vol 640 ◽  
Author(s):  
Nabil Sghaier ◽  
Abdel K. Souifi ◽  
Jean-Marie Bluet ◽  
Manuel Berenguer ◽  
Gérard Guillot ◽  
...  
Keyword(s):  
Gate Voltage ◽  
Frequency Dispersion ◽  
Buffer Layers ◽  
Si Substrate ◽  
Substrate Interface ◽  
Si Substrates ◽  
Kink Effect ◽  
Parasitic Effect ◽  
Output Characteristics ◽  
Output Conductance

ABSTRACTThe aim of this work is to study the origin of parasitic phenomena in the output characteristics of 4H-SiC MESFETs on semi-insulating (SI) substrates with various buffer layers. Ids-Vds measurements as a function of temperature have first been performed. Different parasitic effects such as kink effect, hysteresis effect when the gate voltage is successively increased or decreased, or changes in the output characteristics after a high drain polarization are presented. Random Telegraph Signal (RTS) measurements and frequency dispersion of the output conductance have next been realized. From the obtained results, we propose that the parasitic effect on the output characteristics are correlated with the presence of deep levels located near the semi -insulating substrate interface. The main observed trap is tentatively attributed to the presence of Vanadium in the SI substrate.

Low-Temperature Heteroepitaxy of β-SiC on Si (111) Substrates

1988 ◽  
Vol 116 ◽  
Author(s):  
T. Eshita ◽  
T. Suzuki ◽  
T. Hara ◽  
F. Mieno ◽  
Y. Furumura ◽  
...  
Keyword(s):  
Buffer Layers ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Large Area ◽  
Growth Technique ◽  
X Ray ◽  
Si Substrates ◽  
Substrate Structure ◽  
Sic Films

AbstractWe developed a heteroepitaxial growth technique for large-area β-SiC films on Si substrates without buffer layers at 850ºC and 1000ºC. The substrates were vicinal 4-inch (111) Si wafers. The β-SiC films had smooth surfaces and were crack-free. X-ray diffraction and electron diffraction analysis revealed that the films grown at 1000ºC were single crystals. Satisfactory characteristics were obtained in aMOSFET with a β-SiC/Si02/poly-Si substrate structure. Our evaluations indicate that the β-SiC films were high-quality crystals.

scholarly journals Surface Texturing of Si with Periodically Arrayed Oblique Nanopillars to Achieve Antireflection

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 380
Author(s):  
Jun-Hyun Kim ◽  
Sanghyun You ◽  
Chang-Koo Kim
Keyword(s):  
Aspect Ratio ◽  
Plasma Etching ◽  
Surface Texturing ◽  
Light Reflection ◽  
Si Substrate ◽  
Weighted Mean ◽  
Optical Reflectance ◽  
Si Substrates ◽  
Aspect Ratios ◽  
Shadowing Effect

Si surfaces were texturized with periodically arrayed oblique nanopillars using slanted plasma etching, and their optical reflectance was measured. The weighted mean reflectance (Rw) of the nanopillar-arrayed Si substrate decreased monotonically with increasing angles of the nanopillars. This may have resulted from the increase in the aspect ratio of the trenches between the nanopillars at oblique angles due to the shadowing effect. When the aspect ratios of the trenches between the nanopillars at 0° (vertical) and 40° (oblique) were equal, the Rw of the Si substrates arrayed with nanopillars at 40° was lower than that at 0°. This study suggests that surface texturing of Si with oblique nanopillars reduces light reflection compared to using a conventional array of vertical nanopillars.

scholarly journals Formation and Evaluation of Silicon Substrate with Highly-Doped Porous Si Layers Formed by Metal-Assisted Chemical Etching

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yijie Li ◽  
Nguyen Van Toan ◽  
Zhuqing Wang ◽  
Khairul Fadzli Bin Samat ◽  
Takahito Ono
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Contact Resistance ◽  
Power Factor ◽  
Chemical Etching ◽  
Porous Si ◽  
Si Substrate ◽  
Si Substrates ◽  
Output Performance ◽  
Metal Assisted Chemical Etching

AbstractPorous silicon (Si) is a low thermal conductivity material, which has high potential for thermoelectric devices. However, low output performance of porous Si hinders the development of thermoelectric performance due to low electrical conductivity. The large contact resistance from nonlinear contact between porous Si and metal is one reason for the reduction of electrical conductivity. In this paper, p- and n-type porous Si were formed on Si substrate by metal-assisted chemical etching. To decrease contact resistance, p- and n-type spin on dopants are employed to dope an impurity element into p- and n-type porous Si surface, respectively. Compared to the Si substrate with undoped porous samples, ohmic contact can be obtained, and the electrical conductivity of doped p- and n-type porous Si can be improved to 1160 and 1390 S/m, respectively. Compared with the Si substrate, the special contact resistances for the doped p- and n-type porous Si layer decreases to 1.35 and 1.16 mΩ/cm2, respectively, by increasing the carrier concentration. However, the increase of the carrier concentration induces the decline of the Seebeck coefficient for p- and n-type Si substrates with doped porous Si samples to 491 and 480 μV/K, respectively. Power factor is related to the Seebeck coefficient and electrical conductivity of thermoelectric material, which is one vital factor that evaluates its output performance. Therefore, even though the Seebeck coefficient values of Si substrates with doped porous Si samples decrease, the doped porous Si layer can improve the power factor compared to undoped samples due to the enhancement of electrical conductivity, which facilitates its development for thermoelectric application.

Heteroepitaxial Growth of 3C-SiC on Si (111) Substrate Using AlN as a Buffer Layer

2008 ◽  
Vol 600-603 ◽  
pp. 251-254 ◽  
Author(s):  
Yong Mei Zhao ◽  
Guo Sheng Sun ◽  
Xing Fang Liu ◽  
Jia Ye Li ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
Si Substrate ◽  
Si Substrates ◽  
Good Crystallinity ◽  
Aln Film ◽  
Pressure Chemical ◽  
Aln Buffer ◽  
Sic Film

Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100oC was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300oC indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.

Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Thin Films ◽  
Zno Films ◽  
Si Substrates ◽  
Atomic Force ◽  
Structure Morphology ◽  
Aln Buffer

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

Defect Reduction in GaAs Epilayers on Si Substrates Using Strained Layer Superlattices

1987 ◽  
Vol 91 ◽  
Author(s):  
N. El-Masry ◽  
N. Hamaguchi ◽  
J.C.L. Tarn ◽  
N. Karam ◽  
T.P. Humphreys ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
Defect Reduction ◽  
Strained Layer ◽  
Si Substrates ◽  
Density Of Dislocations ◽  
Strained Layer Superlattice ◽  
Strained Layer Superlattices

ABSTRACTInxGa11-xAs-GaAsl-yPy strained layer superlattice buffer layers have been used to reduce threading dislocations in GaAs grown on Si substrates. However, for an initially high density of dislocations, the strained layer superlattice is not an effective filtering system. Consequently, the emergence of dislocations from the SLS propagate upwards into the GaAs epilayer. However, by employing thermal annealing or rapid thermal annealing, the number of dislocation impinging on the SLS can be significantly reduced. Indeed, this treatment greatly enhances the efficiency and usefulness of the SLS in reducing the number of threading dislocations.

scholarly journals Magnetic Characteristics of Mn-Implanted GaN Nanorods Followed by Thermal Annealing

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Im Taek Yoon ◽  
Yoon Shon ◽  
Younghae Kwon ◽  
Young S. Park ◽  
Chang Soo Park ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Magnetic Phase ◽  
Structural Disorder ◽  
Magnetic Characteristics ◽  
Radio Frequency Plasma ◽  
Si Substrate ◽  
Ferromagnetic Property ◽  
Si Substrates ◽  
Annealing Step ◽  
Frequency Plasma

We have investigated the magnetic and optical properties of dislocation-free vertical GaN nanorods with diameters of 150 nm grown on (111) Si substrates by radio-frequency plasma-assisted molecular-beam epitaxy followed by Mn ion implantation and annealing. The GaN nanorods are fully relaxed and have a very good crystal quality characterized by extremely strong and narrow photoluminescence excitonic lines near 3.47 eV. For GaMnN nanorods, it can be concluded that the ferromagnetic property of GaMnN nanorod with a Curie temperature over 300 K is associated with the formation of Mn4Si7magnetic phase which results from the effects of magnetic and structural disorder introduced by a random incorporation and inhomogeneous distribution of Mn atoms in the porous layer between the nanorods that form precipitates in the Si substrate before or during the annealing step amongst the GaN nanorods.

Monolithic integration of room-temperature cw GaAs/AlGaAs lasers on Si substrates via relaxed graded GeSi buffer layers

2003 ◽  
Vol 93 (1) ◽  
pp. 362-367 ◽  
Author(s):  
Michael E. Groenert ◽  
Christopher W. Leitz ◽  
Arthur J. Pitera ◽  
Vicky Yang ◽  
Harry Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Monolithic Integration ◽  
Buffer Layers ◽  
Si Substrates

Strained-Si Mos Field-Effect Transistors: Building Devices on Relaxed -SI1−xGEx Buffer Layers

1995 ◽  
Vol 379 ◽  
Author(s):  
Jeffrey J. Welser
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Buffer Layers ◽  
Mos Transistors ◽  
Strained Si ◽  
Self Heating ◽  
Experimental Application ◽  
Heating Effects ◽  
Enhanced Mobility ◽  
Output Characteristics

ABSTRACTThe experimental application of strained-Si / relaxed-Si1−xGex heterostructures to n-MOSFETs is discussed, focusing on the enhanced mobility provided by the strain. This paper provides an overview of the theoretically-predicted electronic properties of these heterostructures, as well as their growth. Several practical issues which arise in MOS applications are covered, including the effect of the relaxed-Si1−xGex, buffer layers on diode performance, and the observation of self-heating effects in the output characteristics of the MOS transistors.

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