Influence of Surface Roughness on Breakdown Voltage of 4H-SiC SBD with FLR Structure

2009 ◽  
Vol 615-617 ◽  
pp. 643-646 ◽  
Author(s):  
Akimasa Kinoshita ◽  
Takashi Nishi ◽  
Takasumi Ohyanagi ◽  
Tsutomu Yatsuo ◽  
Kenji Fukuda ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Breakdown Voltage ◽  
Room Temperature ◽  
Light Emission ◽  
Root Mean Square Roughness ◽  
Avalanche Breakdown ◽  
Mean Square ◽  
Electrical Field ◽  
Force Microscopy ◽  
Atomic Force

The Ti/4H-SiC Schottky barrier diodes with a field limiting ring (FLR) structure are fabricated. Two types of SBDs are prepared; one (SBD-A) is covered and another (SBD-B) isn’t covered with a carbon cap during high temperature annealing after ion implantation. The breakdown voltage at room temperature for SBD-A and SBD-B are 1400 V and 1000 V, respectively. The breakdown for both SBDs occurs due to an avalanche breakdown. The light emission images are obtained at the breakdown voltage by photo emission microscope (PEM). The light emission is observed along an FLR of the SBD-A as designed. On the other hand, the spot of light emission is observed on a FLR structure of the SBD-B. This light emission spot indicates that leakage current is concentrated because an electrical field concentration is generated at this one for the SBD-B. The root-mean-square roughness of the Al-implanted region on the FLR structure calculated from the atomic force microscopy (AFM) images for the SBD-A and the SBD-B are 0.697 nm and 5.58 nm, respectively. Therefore it is considered that large surface roughness on the FLR decreases breakdown voltage of SBD because an electrical field concentration is generated at a spot.

Surface Roughness Influence on O2 and Ar RIE Gas Treated Aluminum Surface

2014 ◽  
Vol 925 ◽  
pp. 92-95
Author(s):  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Uda Hashim ◽  
Steven Taniselass ◽  
Moganraj Palianysamy ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Design Of Experiment ◽  
Surface Characteristics ◽  
Aluminum Surface ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Bias Power ◽  
Force Microscopy ◽  
Atomic Force

This study reports on the preliminary investigations on the effect of Reactive Ion Etch (RIE) parameters on the surface characteristics of Al bond pad. Investigation is done employing Design of Experiment (DOE) method. Quantity of Oxygen, Argon, ICP power and BIAS power were varied to get 16 sets of recipes. This provides 16 samples with different combination of RIE parameters. Surface characteristics of the samples were analyzed using Atomic Force Microscopy (AFM).Data collected were in terms of Surface Roughness (RA), Peak Vs Valley (P-V) and Surface Root-Mean-Square Roughness (RMS). Result shows that combination of these RIE parameters does not vastly affect the surface characteristics of the Al bond pad.

Deposition of Cu Films for Laser Mirror by Partially Ionized Beam Deposition

1995 ◽  
Vol 396 ◽  
Author(s):  
Seok-Keun Koh ◽  
Young-Soo Yoon ◽  
Ki-Hwan Kim ◽  
Hong-Gui Jang ◽  
Hyung-Jin Jung
Keyword(s):  
Surface Roughness ◽  
Room Temperature ◽  
Film Surface ◽  
Cu Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cu Film ◽  
Partially Ionized ◽  
Acceleration Voltage ◽  
Beam Deposition

AbstractPartially ionized beam deposition of Cu thin films on glass at room temperature were carried out to fabricate Cu laser mirrors with good structural and reflectance properties. At a constant film thickness of 600 Å, the grain size of as-grown Cu films increased with acceleration voltage, and there was no indication of defects such as cracks and/or large pores in the film surface as shown in scanning electron microscopy images. Root-mean-square(Rms) surface roughnesses of the films with thicknesses of 600 Å were measured by atomic force microscopy. RmS surface roughness increased when acceleration voltage increased from 0 kV to 2 kV, but decreased at the acceleration voltage of 3 kV. RmS surface roughness of the film grown at 4 kV, however, increased again. At the acceleration voltage of 3 kV, reflectance of the films increased with the film thickness until 600 Å and decreased at the film thickness of 800 Å. The reflectance results showed that the Cu film deposited at 3 kV had higher reflectance than that of others. Our results suggest that it is possible to grow the Cu film with good structural and optical properties on glass substrate at room temperature by partially ionized beam deposition.

Anisotropy of Surface Roughness on Aluminium Sheet Studied by Atomic Force Microscopy

2000 ◽  
Vol 6 (2) ◽  
pp. 137-144 ◽  
Author(s):  
George W. Ryan
Keyword(s):  
Surface Roughness ◽  
Rolling Direction ◽  
Rolling Process ◽  
Root Mean Square Roughness ◽  
Force Microscopy ◽  
Aluminium Sheet ◽  
Atomic Force ◽  
Lubrication Performance ◽  
Microscope Images ◽  
The Mean

Atomic force microscope images of aluminium sheet are used to calculate the mean roughness Ra and the root mean square roughness Rq for different directions ([theta]) across the samples. The angle determined values of Ra([theta] and Rq([theta]) are significantly lower in the rolling direction than in any other direction. The results provide a clear demonstration of the vector nature of surface roughness. Local features in an angle determined Rq([theta]) profile are also compared with the positions of peaks and valleys in the matching topographical crosssection of the surface running at right angles to [theta]. It is further found that the distribution of z heights for an imaged sample is usually not Gaussian in shape unless the z heights are measured about mean lines constructed across the surface parallel with the rolling direction. The results are relevant for controlling lubrication performance in the aluminium rolling process.

SiC Coatings Deposited by RF Magnetron Sputtering

2007 ◽  
Vol 280-283 ◽  
pp. 1309-1312 ◽  
Author(s):  
Hui Dong Tang ◽  
Shou Hong Tan ◽  
Zheng Ren Huang
Keyword(s):  
Surface Roughness ◽  
Magnetron Sputtering ◽  
Room Temperature ◽  
Rf Magnetron Sputtering ◽  
Rf Power ◽  
Force Microscopy ◽  
Atomic Force ◽  
Amorphous Sic ◽  
Surface Morphologies ◽  
Sic Coatings

Amorphous SiC coatings were deposited by RF magnetron sputtering from a sintered SiC target onto Si(100) substrate at room temperature. The influence of RF power on the surface morphology and the RMS surface roughness of the resulting SiC coatings was studied by using atomic force microscopy. Two types of surface morphologies were obtained. The corresponding forming mechanisms were also discussed.

Measuring the Changes in InP Morphological and Electrical Specifications Caused by Oxygen Ion Implantation

2011 ◽  
Vol 264-265 ◽  
pp. 1312-1317
Author(s):  
A.H. Ramezani ◽  
M.R. Hantezadeh ◽  
M. Ghoranneviss ◽  
A.H. Sari
Keyword(s):  
Surface Roughness ◽  
Ion Implantation ◽  
Room Temperature ◽  
Implantation Dose ◽  
Force Microscopy ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Atomic Force ◽  
Before And After ◽  
Oxygen Ion Implantation

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5×10 15 to 5×10 17 ions/cm2 and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.

Polarization Switching Behavior of Ferroelectric (NH4)0.39K0.61NO3 Films

2010 ◽  
Vol 93-94 ◽  
pp. 49-58 ◽  
Author(s):  
Navneet Dabra ◽  
Jasbir S. Hundal
Keyword(s):  
Applied Field ◽  
Switching Time ◽  
Polarization Switching ◽  
Nucleation Theory ◽  
Switching Behavior ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Force Microscopy ◽  
Atomic Force ◽  
Maximum Polarization

The polarization switching transients of spray-deposited ferroelectric (NH4)0.39K0.61NO3 (NKN) films have been investigated. Modified Sawyer-Tower circuit has been used to trace the hysteresis loop (P-E). The value of maximum polarization, Ps and coercive field, Ec was found to be 6.58 µC/cm2 and 4.10 kV/cm respectively. The polarization fatigue study has been carried out. The experimental polarization switching transients were fitted well with the Kolmogorov-Avrami-Ishibashi (KAI) nucleation theory The maximum polarization switching current (imax) and maximum switching time (tmax) have been measured as a function of the applied field. The activation field (), dimensionality (n) and switching time have been determined by employing the KAI model to the experimental switching transients. The atomic force microscopy (AFM) has been employed to estimate the grain size (~ 72 nm) and root mean square roughness (rms) (~ 130nm) of the (NH4)0.39K0.61NO3 films and has been correlated with the switching properties.

scholarly journals How levelling and scan line corrections ruin roughness measurement and how to prevent it

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Nečas ◽  
Miroslav Valtr ◽  
Petr Klapetek
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Material Science ◽  
Mean Square ◽  
Roughness Measurement ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scan Line ◽  
Scale Roughness ◽  
Roughness Measurements

Abstract Surface roughness plays an important role in various fields of nanoscience and nanotechnology. However, the present practices in roughness measurements, typically based on some Atomic Force Microscopy measurements for nanometric roughness or optical or mechanical profilometry for larger scale roughness significantly bias the results. Such biased values are present in nearly all the papers dealing with surface parameters, in the areas of nanotechnology, thin films or material science. Surface roughness, most typically root mean square value of irregularities Sq is often used parameter that is used to control the technologies or to link the surface properties with other material functionality. The error in estimated values depends on the ratio between scan size and roughness correlation length and on the way how the data are processed and can easily be larger than 10% without us noting anything suspicious. Here we present a survey of how large is the problem, detailed analysis of its nature and suggest methods to predict the error in roughness measurements and possibly to correct them. We also present a guidance for choosing suitable scan area during the measurement.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

The Reactive Formation of Diblock Copolymer at a Polymer/Polymer Interface and its Effect on Interfacial Structure

2000 ◽  
Vol 629 ◽  
Author(s):  
Jonathan S. Schulze ◽  
Timothy P. Lodge ◽  
Christopher W. Macosko
Keyword(s):  
Molecular Weight ◽  
Interfacial Structure ◽  
Root Mean Square Roughness ◽  
Radius Of Gyration ◽  
Interfacial Region ◽  
Force Microscopy ◽  
Amino Terminal ◽  
Polymer Interface ◽  
Atomic Force ◽  
Time Required

ABSTRACTThe reaction of perdeuterated amino-terminal polystyrene (dPS-NH2) with anhydrideterminal poly(methyl methacrylate) (PMMA-anh) at a PS/PMMA interface has been observed with forward recoil spectrometry (FRES). Bilayer samples were constructed by placing thin films of PS containing ∼8.5 wt % dPS-NH2 on a PMMA-anh layer. Significant reaction was observed only after annealing the samples at 174°C for several hours, a time scale at least two orders of magnitude greater than the time required for the dPS-NH2 chains to diffuse through the bulk PS layer. The topography of the interfacial region as copolymer formed was measured using atomic force microscopy (AFM). Roughening of the PS/PMMA interface was observed to varying degrees in all annealed samples. Furthermore, the extent of this roughening was found to depend on the PS matrix molecular weight. Reaction in the samples with a high molecular weight PS matrix resulted in a root mean square roughness approximately equal to the radius of gyration Rg of the copolymer. However, approximately twice as much roughening was observed in the low molecular weight PS matrix. This study reveals how the molecular weight of one of the phases can affect the rate of reaction at a polymer/polymer interface.

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