Analysis of the deep depletion MOSFET and the use of the d.c. characteristics for determining bulk-channel charge-coupled device parameters

A qualitative and quantitative analysis of the deep depletion MOSFET operated in the regimes of depletion, enhancement and depletion/enhancement, is presented. The quantitative analysis presented here does not make any of the simplifications made in some earlier papers, applicable to shallow channel depletion MOSFETs, and uses a four terminal device model so as to provide a complete set of characterisation equations for each mode of operation.It is demonstrated that the device parameters of flatband voltage, implanted channel doping and depth, and bulk and surface carrier mobilities, can easily be determined by use of some of the characteristics equations in conjunction with simple measurements made directly from the drain current/drain voltage characteristics. Furthermore these parameters are applicable to bulk-channel charge-coupled devices fabricated under the same implantation and drive-in conditions. As the device parameters are determined from the drain current/drain voltage characteristics the techniques presented offer an attractive alternative to the more complicated C-V methods used for bulk-channel charge-coupled device characterisation.The validity of the model and the techniques used to determine the device parameters is demonstrated by the good agreement between calculated and measured results obtained from fabricated devices.     

Performance characteristics of the offset-gate charge-coupled device

A technique for producing high-density two-phase overlapping-gate CCD arrays has recently been described. This letter details some of the potential advantages of the technique and presents experimental verification of a particular implementation of this offset-gate CCD.     

A reprogrammable filter bank using charge-coupled device discrete analog-signal processing

A filter bank having up to 32 channels is formed by multiplexing a recursive two-pole delay line filter. Thirty-two sets of filter constants are stored and addressed digitally while multiple delays are provided in analog form by a charge-coupled device (CCD) delay line. The interface between the digitally stored constant and the delayed analog signal occurs in a four quadrant multiplying D/A where the delayed analog signal is weighted by the constant. Sampling and clamping at the CCD interfaces insures accurate bipolar analog operation. The filter hardware is described, the filter constants are derived, and the performance is documented.     

A reprogrammable filter bank using charge-coupled device discrete analog-signal processing

A filter bank having up to 32 channels is formed by multiplexing a recursive two-pole delay line filter. Thirty-two sets of filter constants are stored and addressed digitally while multiple delays are provided in analog form by a charge-coupled device (CCD) delay line. The interface between the digitally stored constant and the delayed analog signal occurs in a four quadrant multiplying D/A where the delayed analog signal is weighted by the constant. Sampling and clamping at the CCD interfaces insures accurate dipolar analog operation. The filter hardware is described, the filter constants are derived, and the performance is documented.     

Counting of deep-level traps using a charge-coupled device

Quantization in dark current generation has been observed for the first time through the use of a virtual-phase charge-coupled device. Two sites for bulk silicon dark current have been identified with capture cross sections of 1.8 × 10^-15cm²and 5.4 × 10^-16cm², and concentrations of 1.3 × 10⁹cm^-3and 1.5 × 10⁸cm^-3, respectively.     

Comments on "A device model for buried-channel CCD's and MOSFET's with Gaussian impurity profiles"

In the above paper, an expression for the silicon-surface potential in the ion-implanted channel region of a depletion MOST includes both the flat-band voltage VFBand the potential difference Δ between the conduction band and the Fermi level. It is shown here that Δ is inherently included in VFBhence, the original expression requires correction.     

The nonlinearity measurement of charge-coupled device array spectrometer using colorful LED

A nonlinearity measurement of the charge-coupled device (CCD) array spectrometer using flux addition and comparison method is described. The light with various colors from the colorful light emitting diode (LED) light source is applied to measure the nonlinearity of the spectrometer at different wavelengths, respectively. An high-end CCD array spectrometer is tested. For colorful LED light sources, the nonlinearity factors of the CCD array spectrometer (absolute value) are as follows:k<0.8% for white light, k <1.1% for red light, k <2.2% for green light and k<4.7% for blue light. By using those quasi-monochromatic light sources, it is shown that the nonlinearity depends on the wavelength. It is important to be wariness about the spectral nonlinearity and related uncertainty evaluation when the narrow-band light source is tested.     

A comparison between backscattering coefficients using Gaussian and non-Gaussian surface statistics

This communication provides a comparison between the backscattering coefficients computed using Gaussian versus non-Gaussian surface statistics. The computations are performed for a class of surface height distributions and surface correlation functions. Results indicate that the coherent component of the scattering coefficient is strongly dependent upon the surface height distribution. The noncoherent component also depends on the surface height distribution and the surface root mean square (rms) slope when the rms surface height is large relative to the incident wavelength. On the other hand, when the surface rms height is moderate or small, the noncoherent component is sensitive mainly to the surface height correlation function.     

Junction capacitance and related characteristics using graded impurity semiconductors

The transition capacitance of a junction of semiconductors with constant impurity density is well-known and varies inversely with the square root of the bias voltage. This paper analyzes the variation of transition capacitance with bias voltage of a junction of semiconductors with graded impurity densities; i. e., densities which are an arbitrary function of position. It is found that the transition capacitance can be simply related to a depletion width and that, in turn, depletion width can be related to the bias voltage. An analysis is also carried out for the impurity grading to produce a specified transition capacitance variation, as for instance, a linear variation of capacitance with bias voltage. It is also possible to determine impurity gradings to satisfy certain special conditions. An example of this type that is considered in some detail is the determination of the impurity grading which will produce avalanche breakdown simultaneously throughout the semiconductor. An important result of the analysis is that the capacitance vs bias voltage relation can be favorably modified by suitable choice of impurity grading (see Fig. 7). The practical realization of the various characteristics considered in this article is contingent upon techniques for fabricating semiconductors with specified impurity gradings.     

Efficient modeling of thyristor static characteristics from device fabrication data

A method for determination of the dc characteristics of an n-p-n-p structure is described. Each of the three diffused regions is first of all characterized by computer analysis using the variable boundary regional approach at one low-bias value (mobility variation with doping level and high doping bandgap reduction effects are included in this program). A set of constants thus obtained is used to define a set of simplified analyticI-Vrelations for each of the four regions. These analytic relations are solved using an elementary program to predict theI-Vcharacteristics. Experimental and computed results are included for normal and gold-doped devices and explanations for operation with extreme (low- and high-) lifetime values are given.     

A comparison of static and dynamic characteristics between rectuseye muscle and linear muscle model predictions

The characteristics of a muscle model are analyzed using rectus eye muscle parameter values and compared to rectus eye muscle data. The muscle is modeled as a viscoelastic parallel combination connected to a parallel combination of active state tension generator, viscosity element, and length tension elastic element. Each of the elements is linear and their existence is supported with physiological evidence. The static and dynamic properties of the muscle model are compared to rectus eye muscle data. The length-tension characteristics of the model are in good agreement with the data within the operating region of the muscle. With the muscle model incorporated into a lever system to match the isotonic experiment paradigm, simulation results for this linear system yield a nonlinear force-velocity curve. Moreover, the family of force-velocity curves generated with different stimulus rates reported in the literature match the predictions of the model without parametric changes. The results of this paper are important in studies involving the oculomotor plant and oculomotor neural networks. Additionally, these results may be applicable to other muscles.     

基于CCD的侧向激光雷达系统研制及探测个例

后向散射激光雷达技术已广泛应用于大气气溶胶的探测,但由于有盲区和过渡区,限制了它在近距离段的探测范围和精度。侧向散射激光雷达技术没有后向散射激光雷达技术中的上述缺陷,可实现近距离段气溶胶信号的连续探测,且探测精度较高。开发研制了基于CCD的侧向散射激光雷达系统,它由激光发射、光学接收、几何定标及数据采集等子系统组成。与后向散射激光雷达的对比探测个例表明,该激光雷达系统数据可靠,近距离的有效探测范围为0.02~4 km。这一系统的建立为进一步深入研究近地面层的气溶胶时、空分布奠定了坚实的基础。     

Extraction of device noise sources from measured data using circuitsimulator software

A procedure is presented for extracting the properties of device noise sources from experimental data. The extraction procedure can be implemented using commercially available circuit simulators. An example concerning a low-noise pseudomorphic high-electron-mobility transistor (HEMT) shows that the two noise sources extracted from experimental data are largely uncorrelated provided that parasitic elements are de-embedded from the measurement and that the sources are extracted in H-parameter format     

A comparison of far-field methods for determining mode fielddiameter of single-mode fibers using both Gaussian and Petermanndefinitions

An interlaboratory comparison is presented of far-field measurement methods for determining mode field diameter of single-mode fibers. The comparison was conducted by member of the Electronic Industries Association. Measurements were made on dispersion-unshifted and dispersion-shifted fibers at 1300 and 1550 nm. Results were calculated using both Petermann and Gaussian definitions. The Petermann definition gave better agreement than the Gaussian in all cases. A systematic offset of 0.52 μm was observed between methods when applied to dispersion-shifted fibers. Such an offset may be caused by limited angular collection     

相干和非相干平顶高斯光束的比较研究

对完全相干和非相干平顶高斯光束的传输特性作了详细研究。提出了用有限个拉盖尔-高斯模或厄米-高斯模的部分相干迭加来产生部分相干平顶高斯光束,以满足某些实际应用要求的新方法。     

A comparison of cloud droplet radii measured from space

Cloud droplet effective radius (CDR) can be estimated from the spectral signature of cloud reflectance. The technique has been applied to measurements of the Advanced Very High Resolution Radiometer instrument and more recently to the Moderate Resolution Imaging Spectroradiometer (MODIS). Another technique relies on the directional signature of the polarized reflectance and has been applied to observations from Polarization and Directionality of the Earth's Reflectances (POLDER) onboard Advanced Earth Observation Satellite (ADEOS). Although the latter technique requires very specific conditions, we argue that, when applicable, it is very accurate. A large fraction of successful POLDER estimates are derived from measurements over stratocumulus cloud fields. During portions of 2003, POLDER and MODIS acquired near coincident observations. The data can then be used for an evaluation of the two CDR products. The two datasets are highly correlated over the oceans albeit with a MODIS high bias of about 2 /spl mu/m. The correlation breaks down when POLDER retrieves small droplets (less than 7 /spl mu/m), which occurs over most land surfaces as well as polluted oceanic areas. We discuss the possible causes for biases and errors. Although differences in the two CDR estimates are expected because of the differences in the spatial scale and vertical weighting function, we did not find a fully satisfactory explanation for the bias and lack of correlation over land surfaces. It seems, however, that the spatial variability as seen by MODIS is larger than that deduced from POLDER measurements, in particular over land surfaces.     

Performance comparison between Gaussian interleaver, Rayleigh interleaver, and dithered golden interleaver

This paper is a proposal for a new form of random interleaver for a turbo code based on the probability distribution of channel statistic model of transmission, instead of a uniform probability distribution. In our work, we use the normal (Gaussian) and Rayleigh probability distribution in accordance with the channel type and compare them with classic random interleaver (uniform distribution) and with dithered golden interleaver [invention of the Communications Research Centre (CRC)]. The results show that this new form of random interleaver gives identical results compared to the simulated case of dithered golden interleaver.     

A comparison of measured radar cross section of solid and mesh ogives

An experimental program was conducted in which the radar cross section (RCS) of solid and mesh ogive models was measured and compared. The data covered an ogive length to wavelength ratio varying by a factor of 100. The various ogive models, the measurement ranges employed, and typical data are discussed in detail. Some of the conclusions drawn from the study are as follows. 1) For smooth ogives there is a substantial increase in RCS when part or all of its illuminated surface is replaced by mesh. At higher frequencies, the contribution to the RCS from the illuminated mesh area dominates; that from the shadow side is negligible even in the case of off-axis incidence. 2) The measured on-axis RCS of a mesh ogive exhibits oscillatory behavior about a mean value as the frequency is varied. Furthermore, it is found that this value agrees with that calculated for a rough ogive if the scale of roughness is properly chosen. 3) There is a frequency limit below which the mesh ogive RCS is identical to that of a solid ogive. At this frequency, the mesh opening along the axial geodesic direction is no larger than0.03lambda.     

A new method for the two-dimensional calculation of the potential distribution in a buried-channel charge-coupled device: Theory and experimental verification

This paper describes a new method for calculating the potential distribution in the depleted top layer and in the substrate of a buried-channel charge-coupled (BCCD) device. The depletion approximation is used. The experimental verification of the method is done by comparing the results with measured values for the maximum channel potential ΦMAX, the location Ymof that maximum, and the locationHof the edge of the p-n depletion layer into the substrate.