Growth, processing and characterization of GaN/AlGaN/SiC vertical n-p diodes

2005 ◽  
Vol 892 ◽  
Author(s):  
Steven Boeykens ◽  
Maarten Leys ◽  
Marianne Germain ◽  
Jef Poortmans ◽  
Benny Van Daele ◽  
...  

AbstractApplication of SiC substrates instead of the most commonly used sapphire for the heteroepitaxial growth of III-Nitrides offers advantages as better lattice matching, higher thermal conductivity, and electrical conductivity. This namely offers interesting perspectives for the development of vertical III-Nitride devices for switching purposes. For example, an AlGaN/SiC heterojunction could improve the performance of SiC bipolar transistors. In this work, n-type GaN layers have been grown by MOVPE on p-type 4H-SiC substrates using Si doped Al0.08Ga0.92N or Al0.3Ga0.7N nucleation layers. They have been characterized with temperature dependent current-voltage (I-V-T), capacitance-voltage (C-V) techniques and transmission electron microscopy (TEM).

2003 ◽  
Vol 768 ◽  
Author(s):  
A. Fontcuberta i Morral ◽  
J. M. Zahler ◽  
Harry A. Atwater ◽  
M. M. Frank ◽  
Y. J. Chabal ◽  
...  

AbstractA study of the interfacial properties of wafer bonded InP/Si is presented. The electrical properties are measured by bonding InP to Si with different doping concentrations and by measuring the current voltage characteristics of the bonded pairs. Two different kinds of structures are studied: 1) n+InP doped to 3×1018 cm-3 bonded with n+Si doped to 1×1019 cm-3, and 2) n+InP doped to 3×1018 cm-3 bonded with p-Si doped to 6×1014 cm-3. After a 350°C anneal, structure 1 shows low resistive ohmic behavior while structure 2 is rectifying due to its higher sensitivity to interfacial chemistry. Indeed, both the reverse and forward current are reduced by annealing in structure 2, suggesting the formation of an interfacial barrier during annealing. This hypothesis is supported by High Resolution Transmission Electron Microscopy combined with Fourier Transform Infrared Spectroscopy, which indicate the formation of an amorphous interfacial oxide from the reaction of adsorbed water trapped at the InP/Si interface.


2003 ◽  
Vol 763 ◽  
Author(s):  
A. Fontcuberta i Morral ◽  
J. M. Zahler ◽  
Harry A. Atwater ◽  
M. M. Frank ◽  
Y. J. Chabal ◽  
...  

AbstractA study of the interfacial properties of wafer bonded InP/Si is presented. The electrical properties are measured by bonding InP to Si with different doping concentrations and by measuring the current voltage characteristics of the bonded pairs. Two different kinds of structures are studied: 1) n+InP doped to 3×1018 cm-3 bonded with n+Si doped to 1×1019 cm-3, and 2) n+InP doped to 3×1018 cm-3 bonded with p-Si doped to 6×1014 cm-3. After a 350°C anneal, structure 1 shows low resistive ohmic behavior while structure 2 is rectifying due to its higher sensitivity to interfacial chemistry. Indeed, both the reverse and forward current are reduced by annealing in structure 2, suggesting the formation of an interfacial barrier during annealing. This hypothesis is supported by High Resolution Transmission Electron Microscopy combined with Fourier Transform Infrared Spectroscopy, which indicate the formation of an amorphous interfacial oxide from the reaction of adsorbed water trapped at the InP/Si interface.


Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.


1995 ◽  
Vol 391 ◽  
Author(s):  
W.F. Mcarthur ◽  
K.M. Ring ◽  
K.L. Kavanagh

AbstractThe feasibility of Si-implanted TiN as a diffusion barrier between Cu and Si was investigated. Barrier effectiveness was evaluated via reverse leakage current of Cu/TixSiyNz/Si diodes as a function of post-deposition annealing temperature and time, and was found to depend heavily on the film composition and microstructure. TiN implanted with Si28, l0keV, 5xl016ions/cm2 formed an amorphous ternary TixSiyNz layer whose performance as a barrier to Cu diffusion exceeded that of unimplanted, polycrystalline TiN. Results from current-voltage, transmission electron microscopy (TEM), and Auger depth profiling measurements will be presented. The relationship between Si-implantation dose, TixSiyNz structure and reverse leakage current of Cu/TixSiyNz/Si diodes will be discussed, along with implications as to the suitability of these structures in Cu metallization.


Author(s):  
C. Ballesteros ◽  
J. A. Garci´a ◽  
M. I. Orti´z ◽  
R. Rodri´guez ◽  
M. Varela

A detailed tribological characterization of low-energy, nitrogen implanted V5 at. %Ti alloy is presented. Samples were nitrogen-implanted at an accelerating voltage of 1.2 kV and 1 mA/cm2, up to a dose of 1E19 ions/cm2. The tribological properties of the alloys: microhardness, friction coefficient and wear resistance, have improved after ion implantation and this improvement increases as the implantation temperature increases. The microstructure of the alloys were analysed by transmission electron microscopy. A direct correlation between structural modifications of the nitrogen implanted layer and the improvement in their tribological properties is obtained. For samples implanted at 848 K a nanocomposite layer where the reinforcement particles are TiN precipitates forms. TiN precipitation appears as the responsible of the improvement in the tribological properties.


1999 ◽  
Vol 607 ◽  
Author(s):  
S. Kato ◽  
T. Horikoshi ◽  
T. Ohkubo ◽  
T. Iida ◽  
Y. Takano

AbstractThe bulk crystal of silicon germanium was grown by vertical Bridgman method with germanium composition, x, varying from 0.6 to 1.0. The temperature dependent variation of the mobility is indicative of alloy scattering dominantly for the bulk wafer. Phosphorus was diffused in as-grown p-type bulk wafer at 850 °C to form pn-junction, and the diffusion coefficient of phosphorus was evaluated as a function of x. The diffusion behavior of phosphorus in silicon germanium is closely correlated with the germanium self-diffusion with changing x. For specimens with lower content x, P concentration profiles indicated “kink and tail” shape, while it was not observed for higher x. For current-voltage characteristics measurement, an ideality factor was obtained.


1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.


2018 ◽  
Vol 96 (7) ◽  
pp. 816-825 ◽  
Author(s):  
H.H. Güllü ◽  
M. Terlemezoğlu ◽  
Ö. Bayraklı ◽  
D.E. Yıldız ◽  
M. Parlak

In this paper, we present results of the electrical characterization of n-Si/p-Cu–Zn–Se hetero-structure. Sputtered film was found in Se-rich behavior with tetragonal polycrystalline nature along with (112) preferred orientation. The band gap energy for direct optical transitions was obtained as 2.65 eV. The results of the conductivity measurements indicated p-type behavior and carrier transport mechanism was modelled according to thermionic emission theory. Detailed electrical characterization of this structure was carried out with the help of temperature-dependent current–voltage measurements in the temperature range of 220–360 K, room temperature, and frequency-dependent capacitance–voltage and conductance-voltage measurements. The anomaly in current–voltage characteristics was related to barrier height inhomogeneity at the interface and modified by the assumption of Gaussian distribution of barrier height, in which mean barrier height and standard deviation at zero bias were found as 2.11 and 0.24 eV, respectively. Moreover, Richardson constant value was determined as 141.95 Acm−2K−2 by means of modified Richardson plot.


2014 ◽  
Vol 1024 ◽  
pp. 120-123
Author(s):  
Nezar Gassem Elfadill ◽  
M. Roslan Hashim ◽  
Khaled M. Chahrour ◽  
Chun Sheng Wang

Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}Nanocrystalline cupric oxide (CuO) film was prepared by sputtering of pure copper metal on n-type single crystalline Si substrate under argon-oxygen ambient. Structural and morphological analyses of the as-deposited CuO films were performed by X-ray diffraction (XRD) diffractometer and Field Emission Scanning Electron Microscopy (FESEM). The results show Single crystalline granular nanocrystalline (002) CuO films, with 18 nm crystallite size. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were performed for p-CuO/n-Si hetrojunction. Diode parameters such as saturation current (Is=9.5E-6 A) and ideality factor (n=1.86) were extracted from the dark I-V characteristics. Potential barrier height of the junction (ϕi=1.1V) was revealed from (1/C2- V) plot. Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}


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