J.M. Pimbley's research while affiliated with Rensselaer Polytechnic Institute and other places

Publications (55)

Article
Many electron devices and chemical reactions depend on the escape rate of particles confined by potential wells. When the diffusion coefficient of the particle is small, the carrier continuity or the Smoluchowski equation is used to study the escape rate. This equation includes diffusion and field-aided drift. In this work solutions to the Smolucho...
Article
Structural effects of sub-monolayer epitaxial films are described by the pair correlation function of surface atoms. We have developed a new scheme to evaluate this atomic pair correlation function analytically and exactly for the combined overlayer and substrate system during the first stages of epitaxy. We employ this correlation function to calc...
Article
The log-normal probability density function has been used extensively in the characterization of membrane pore size distributions and in the theoretical analysis of the effect of these distributions on membrane transport. There has, however, been considerable discrepancy regarding the proper functional form for this probability distribution as well...
Article
It is well known that SiC can be thermally oxidized to form SiO <sub>2</sub> layers. And Si MOSFET IC's using thermally grown SiO<sub>2 </sub> gate dielectrics are the predominant IC technology in the world today. However the SiC/SiO<sub>2</sub> interface has not been well characterized as was the case for Si MOS in the early 1960's. This paper pre...
Article
A separable quasi 2-D spectral estimation algorithm is presented. This hybrid algorithm combines the 1-D minimum free-energy method with the 1-D periodogram. The algorithm reduces to the corresponding maximum entropy hybrid spectral estimator in some cases. The minimum free-energy hybrid algorithm is preferable to the maximum entropy version when t...
Article
Analytical device-physics-based models for subthreshold drain current in short channel SOI MOSFETs facilitate accurate and efficient circuit simulation. These models also enable prediction of device scaling limits determined by subthreshold conduction and comparison of these limits with bulk MOSFETs for the same threshold and supply voltages
Article
A new group-specific affinity membrane using metal chelates as ligands and inorganic glass hollow fiber microfiltration membranes as support matrices is developed and tested. The study focused on developing the optimum activation and coupling procedures to bind the chelating agent (iminodiacetic acid, IDA) to the surface of the microporous glass ho...
Article
SiC photodiodes were fabricated using 6 H single-crystal wafers. These devices have excellent UV responsivity characteristics and very low dark current even at elevated temperatures. The reproducibility is excellent and the characteristics agree with theoretical calculations for different device designs. The advantages of these diodes are that they...
Article
Full-text available
In a continuing study of membrane fouling, we report on the behavior of dilute particle suspensions in a rotating annular filter with a nominal 0.45 μm surface modified polysulfone microfiltration membrane. Particle size (25.7, 11.9, and 2.02 μm), particle type (styrene/divinylbenzene and styrene/polyvinyltoluene), transmembrane pressure (10–100 kP...
Article
Membrane fouling is dissected into pore narrowing and constriction, pore plugging and deposition of a gel/cake onto the upstream face of a membrane. Using a rotating annular membrane filter as a diagnostic tool, we have identified these fouling components with the aid of pemeation flux-transmembrane pressure plots. The choice of the rotating annula...
Article
Summary form only given. The operation of current sensors (or pilots) in IGBTs (insulated-gate bipolar transistors) is described experimentally and with two-dimensional simulations. Two different sensor structures are compared. In the most conventional structure, a small IGBT, separated from the main device by metallization only, is used as a curre...
Article
A digital signal processing technique applicable to power spectrum estimation, designated as the minimum free energy method, is described. With no a priori model assumption and no attempt to extract special features such as sinusoids, one can obtain high resolution even with high noise contamination of the measured signal. The technique is demonstr...
Article
For original paper `Approximate analytical solution of generalized diode equation' by T.A. Fjeldy et al. see ibid., vol.38, no.8, p.1976-7, Aug. 1991. The authors significantly enhanced the efficiency with which one may solve the generalized diode equation in numerical circuit simulation programs. This study concluded that Newton-Raphson iteration...
Article
Numerical and analytical solutions of the carrier continuity equation are found for the problem of charge transfer in charge-coupled devices in the presence of potential barriers. The analytical solution is for a rectangular potential barrier and is useful for obtaining a qualitative understanding of charge transfer over a potential barrier. Numeri...
Article
Correlated double sampling (CDS) provides an excellent method for the reduction of kTC noise in analog signal processing. The authors derive the CDS output power for two-circuit realizations of the double sampling procedure. One realization employs two MOSFET switches while the other replaces one switch with a delay element. Although the methods ar...
Article
Generation and recombination of charge carriers dominate some performance aspects of semiconductor devices. Investigation of charge carrier recombination is frustrated by the paucity of direct measurement techniques for the recombination process. We formulate and solve the mathematics governing one such technique. Our solution relates a measured ch...
Article
The recursive maximum likelihood estimation (RMLE) algorithm conceived by Kay (see ibid., vol.ASSP-31, p.56, 1983) is extended to complex data sets. The complex version requires the same level of computation as that for real data. The original development was restricted to the case of realm data. The purpose is to extend RMLE to the more universal...
Article
Nuclear magnetic resonance flow imaging (MRFI) was used to measure fluid flow noninvasively in the extracapillary space (ECS) of a hollow-fiber bioreactor without cells. Agreement between these axial flow measurements in a single hollow-fiber module and predicted axial velocity contour plots at various image planes along the path length was good. F...
Article
A new method of parametric spectral estimation, which is called minimum-free-energy (MFE) estimation, is introduced. The MFE method produces a generic theoretic estimation model that is particularly relevant to signal-analysis problems that suffer from incomplete and/or noisy data. In the general MFE formulation, the objective function is defined a...
Article
The formulation and solution of the equations governing transistor subthreshold behavior in explicit analytical form provide quantitative predictions for minimum feature length as well as immediate information on the relative importance of all major transistor fabrication parameters. Such a formulation and a solution for subthreshold conduction are...
Conference Paper
Low SNR simulations comparing the minimum-free-energy (MFE) spectral estimation algorithms of Silverstein and Pimbley (1988) with the reduced rank modified covariance eigenanalysis algorithm of Tufts and Kumaresan (1982) have been performed. Two different MFE algorithms are discussed and simulated. The results of the statistical analyses demonstrat...
Article
This work presents and evaluates three classes of definite integrals which can arise in the signal processing analysis of coherent imaging systems. All integrals yield to the method of contour integration in the complex plane. Such a treatment requires physically reasonable constraints on the beam divergence, apodizing function of the phased array....
Article
Estimation of important properties of p-n junctions such as reverse leakage current and capacitance is greatly facilitated by the depletion approximation. Computation of the electrostatic potential and electron and hole concentrations within this approximation are commonplace in the microelectronics industry. The depletion approximation requires ap...
Article
Recent research has focused on the mathematical formulation of charge-carrier emission over energy barriers in semiconductor devices. The description of this process includes an improper integral that cannot be evaluated explicitly. Approximate representations based on the Gauss-Laguerre quadrature are proposed for high accuracy over the physical r...
Article
An expression is derived that allows the resistance and capacitance per unit length in a distributed resistance-capacitance line to be determined with one measurement of AC current at a single frequency. These distributed structures occur frequently in semiconductor electronics and determine the device frequency response. The method is intended for...
Article
Series resistance in the metal-oxide-semiconductor field-effect transistor becomes increasingly important as design rules shrink. Material properties associated with the interconnect metal, the semiconductor, and the interface separating the two regions thus assume greater importance. An analytical formulation of the resistance in terms of these ma...
Article
Johnson noise is often the dominant noise source in microelectronic devices. While the magnitude and frequency dependence of noise within a network of discrete resistors and capacitors is well documented, there appears to be a lack of analogous results for distributed resistor‐capacitor systems. This latter model is quite relevant to microelectroni...
Article
Solid-state image sensors continue to find many applications as fabrication technology improves. Due in part to the relatively small role that image sensors have played in the semiconductor world, there exists very little experience in performance modeling of this class of devices. In this paper we discuss a three-dimensional model of the image sen...
Article
Some of the trends in integrated circuit process development are described. The motivations or technical reasons for this activity are discussed. This effort will continue to develop the downsizing that increases functional density and performance. Limiting factors are examined and new technical developments that could enable CMOS density to be com...
Article
Parasitic resistance in the metal-oxide-semiconductor field-effect transistor becomes increasingly important as design rules shrink. The majority of this resistance arises from the contact resistance of the metal-semiconductor interface and the resistance of the semiconductor source and drain regions. The most popular method for deriving current fl...
Article
Novel metallization schemes for submicrometer device interconnections abound in the continuing quest to increase layout density. As dimensions shrink, the current density flowing in these interconnection lines increases. For this reason, design and fabrication processes must seek to alleviate the possibility of electromigration failure. One factor...
Article
Series resistance within the metal-oxide-semiconductor field-effect transistor erodes some of the performance improvement inherent to channel length reduction. The subject of series resistance, then, assumes greater importance as transistor dimensions shrink. Since current crowding effects at the source-drain ohmic contact and at the junction of th...
Article
New buried and graded/buried lightly doped drain (LDD) structures have been demonstrated, for the first time, to improve significantly the hot-electron reliability of NMOS devices. Both LDD structures have peak doping of the n- spacer implant approximately 1000 A below the Si-SiO 2 interface forming a "buried" n- spacer near the drain region. In th...
Article
We formulate a two‐dimensional ordering model for a finite‐level system of adatoms on a crystalline surface. The placement of steps in the two surface directions obeys Markovian disorder. Steps in the two directions are weakly correlated due to the restriction that the system occupies only a finite number of levels in the vertical dimension. In par...
Article
We have constructed and solved an overlayer island growth model in which the distribution of the islands obeys an ''extended geometric distribution function.'' This model describes quantitatively the growth of oxygen p(2 x 1) islands on a W(112) surface as the coverage is increased from 0 to 1. The average size of the islands is seen to increase sh...
Article
The thermodynamic properties of the classical ideal gas are well known and documented. The departure of real gases from ideal behavior requires modification of the ideal equation of state. We derive an exact solution for an ``excluded volume'' system in which the constituent particles have nonzero volume and only one particle may occupy a specific...
Article
An integral representation of the diffracted intensity from one‐dimensional stepped surfaces and overlayers is obtained based on the single‐scattering (kinematic) theory. We find exact solutions for an arbitrary terrace or island size distribution on stepped surfaces or epitaxial layers in an extremely simple manner. This theory greatly expands the...
Article
The distribution of antiphase boundaries created in an overlayer after quenching from a two-dimensional lattice gas phase is described by Markovian disorder. We show that many types of antiphase boundaries with different widths are possible. This one-dimensional distribution is used to describe the growth of oxygen p(2 × 1) antiphase domains along...
Article
Channel hot-electron (CHE) injection poses a reliability problem for n-channel field-effect transistors with small design rules. One often assesses the reliability of a particular fabrication process and design by subjecting individual transistors, instead of an entire circuit, to continuous or pulsed voltage stress. Simple inspection of the linear...
Article
Diffraction techniques are potentially powerful probes of atomic steps on crystalline surfaces. Correlation among the surface steps yields information on the interactions among steps. We consider surfaces with a cut-off geometric distribution of terrace widths which result from strong, short-range step-step interactions. We calculate the diffractio...
Article
We have evaluated the two‐dimensional atomic pair correlation function for surfaces containing finite layers of adsorbed atoms and having a random distribution of steps. The step probabilities for the two lateral directions are mutually dependent. We employ a third‐rank tensor formalism to describe the two‐dimensional array of occupation probabilit...
Article
Quantitative analysis of data obtained using Auger-electron spectroscopy and low-energy electron diffraction (LEED) indicate that the p(1×2) structure of oxygen chemisorbed on a W(112) surface corresponds to a coverage of 1.5 monolayer. A possible second-layer adsorption model is proposed to describe the p(1×2) structure. The densities of the antip...
Article
We have derived an exact expression for the one‐dimensional atomic pair correlation function of the combined overlayer and substrate system in the very first stages of epitaxy. The overlayer can have an arbitrary island size distribution. This pair correlation function is then used to evaluate the widths and shapes of low‐energy (or high‐energy) el...
Article
Low energy electron diffraction is a surface sensitive tool which is most widely used for the determination of surface symmetries and equilibrium atomic positions. Experimental and theoretical advances made in the past five years make it possible now to use LEED also for the characterization of a wide variety of surface defect structures. In this p...
Chapter
Extended defects (such as steps) on imperfect, periodic surfaces and relative positions of surface adsorbates may both exhibit short-range order. One powerful technique for studying this surface ordering is spot profile analysis of diffraction (low-energy and high-energy electron, atom and X-ray) measurements. This analysis requires only kinematic...
Article
Hot-electron reliability problems are of great importance in small geometry n-channel field-effect transistors. Accumulation of negative charge within the gate insulator and creation of interface states represent the two dominant degradation mechanisms. Since MOSFET noise is ascribed to Si-SiO 2 interface states, one might reasonably expect this no...
Article
Interface states in the metal-oxide-semiconductor (MOS) system have a great influence on the electrical properties of MOS capacitors and field-effect transistors. Several methods for measuring the density of these interface states within the forbidden band gap of silicon employ differential capacitance versus gate bias (C-V) measurement on MOS capa...
Article
Hsu and Grinolds recently compared channel hot-electron (CHE) stress results of conventional and "extended drain" NMOS FET's. [1]. They observe increasing degradation as the extended drain resistance increases when the drain bias is defined as that which produces a fixed substrate current. A model in which the hot-electron stress induces surface st...
Article
We have developed a new scheme to evaluate the atomic pair correlation function analytically and exactly for the combined overlayer and substrate system during the first stages of epitaxy. This function describes the morphology of growth on the atomic scale. The overlayer atoms can be a random lattice gas or islands with an arbitrary distribution o...
Article
We present an epitaxial growth model in which a random occupation of substrate lattice sites is assumed before the completion of each layer in layer-by-layer growth. The atomic pair correlation function of the combined adsorbate and substrate system is evaluated. Based on this correlation function we have calculated in closed-form the backscattered...
Article
We have developed a scheme to evaluate the atomic pair correlation function exactly for stepped surfaces and interfaces. This pair correlation function is particularly useful in calculating the diffracted beam width and shape from an arbitrary distribution of steps using low‐energy electron diffraction, reflection high‐energy electron diffraction,...
Article
Knowledge of the infrared optical constants of PtSi is required for quantum yield calculations of Schottky barrier IR imagers with PtSi electrodes. We employ Rutherford backscattering spectrometry to identify the PtSi phase and calculate the infrared optical constants from reflectance data by a Kramers–Kronig analysis technique. Several examples of...

Citations

... It is reported [27][28][29] that X-ray induces surface states 0.25 eV above the midgap. The surface states observed in the present study are located slightly below the midgap, i.e., 0.3 eV below the radiationinduced surface states. ...
... In embedded chemical reactions, the Nernst equation of an embedded compound can be derived by the lattice gas model (LGM) which is proposed based on the thermodynamic ideal solution during studying non-stoichiometric compounds [40,41]. According to the principle of Monte Carlo, the intercalation/deintercalation process of Li + is seen as the free gas occupying position of the LGM and the ideal gas law reflects the characteristics of free gas [42,43]. Fig. 1a shows the schematic diagram of a LIB whose anode and cathode materials are graphite and NCM (LiNi x Mn y Co 1-x-y O 2 , Ni:Co: Mn=5:2:3), respectively. ...
... MRI is an in-situ and non-invasive analytical tool which is capable to characterize filtration processes [5][6][7][8][9][10][11][12][13][14][15][16]. Contrary to optical methods, it is possible with MRI to observe in-out filtration spatiotemporally resolved. ...
... The Pair Correlation Function (PCF) is a probability density function (also known as the radial distribution function or pair separation function) for the clustering of certain objects or events in space and/or time coordinates (Pimbley & Lu 1985) and is useful for measuring the degree of packing. We have used a one-dimensional PCF, which identifies the clustering of events (the bursts pulses of a bright phase in our case), in the time series data. ...
... On the other hand, slow growth rates facilitate several high-tech processes as advantage and are paramount to ensure uniform high quality and pinhole defect free films over large areas. Since the origin of ALD technology is to deposit epitaxial layers on semiconductor substrates and were known as Atomic Layer Epitaxy (ALE) (Pimbley and Lu, 1985;Goodman and Pessa, 1986;Ide et al., 1988;Gong et al., 1990;Yu, 1993;Bedair, 1994), which demands thin dielectric gate oxide films (barrier layers) to control leakage current at minimum film thickness (Puurunen, 2005). Furthermore, in photonics high quality and dense thin films are of significant importance to confine propagating modes via lithographically fabricated nano-structured topographies (Riyanto et al., 2012). ...
... where Ch= ~,PlPl+h. Equivalently the terrace distribution can be evaluated from the diffuse profile [15] or vice versa [16][17][18], but these calculations are very difficult. It has been reported [14] that the broadening may generally expressed by ...
... At first, the voltage fluctuations in a circular core-coat conductor are described on the basis of the thermodynamics of thermal fluctuations 15,16 and of the Johnson−Nyquist noise in a distributed system. 17 Then, a measurement of the PSD is presented for a dissociated snail neuron in its resting state on an array of sensor transistors, taking advantage of cell-solid interfacing with identified snail neurons 11 and on integrated neurochips fabricated by CMOS technology. 12 Finally, the spectral data, as well as the spatial profile of the PSD, are interpreted in terms of the core-coat conductor model of the Johnson−Nyquist noise. ...
... Previous theoretical investigations, primarily for two-level systems such as ideal layer-by-layer growth on crystals without miscut, have shown that the total scattering intensity can be split into the sum of CTR and diffuse components I total = I CT R + I di f f use . 29, 36,37,38 This statistical interpretation of scattering has enabled extensive studies of thin-film growth. 30 Here we focus on the CTR scattering intensity associated with reciprocal lattice point G, which may be either specular or off-specular. ...
... The refractive indices for an Au-coated tip (PPP-NCHAu), PtSi-coated tip (PtSi-NCH), and bare-Si tip (PPP-NCHR) from Nanosensors Inc. are n~7.70 21 , 8.27 22 , and 3.42 19 , respectively, at 1268 cm −1 , with their tip radii guaranteed to be~30, 25, and 10 nm, respectively. Note that the bulk refractive indices are still applicable until the coating thickness exceeds ten nm 23,24 . ...
... The methods that use high rotation speeds to generate centrifugal force for solid-liquid separation are dynamic filtration and high-shear-force crossflow filtration, which generates a high shear force on the membrane surface to produce relative motion between the membrane and casing [14]. Two pieces of commercial equipment with different structures can be used for this process: a cylindrical Couette device [15,16] and a rotating disk [17]. The former uses the relatively high-speed rotation of two coaxial cylinders to generate high shear stress, and the inner cylinder is a membrane. ...