GaAs HBT's for high-speed digital integrated circuit applications

GaAs HBT technology has emerged as one of the most important developments for digital circuits operating at clock frequencies of 100 MHz and higher. High-speed frequency dividers operating as high as 34.8 GHz and VLSI circuits as complex as 32-b CPU's operating at 200-MHz clock rate have been demonstrated. This paper reviews the role of GaAs HBT technologies for high-speed digital IC applications. The requirements for high-speed IC's and the characteristics of various HBT device structures and logic families are discussed. A summary of published results of the ultrahigh-speed circuits and the status of several high-speed VLSI circuits are presented to provide a guide for future developments     

Silicon—Aluminum gate complementary IGFET's

Silicon-aluminum gate complementary IGFET'S have been fabricated with threshold voltages in the range of 0.5-0.7 V. This was accomplished by a two-source evaporation process in which aluminum and at least 10 percent silicon were used for the gate electrode.     

An improved GaAs MESFET equivalent circuit model for analog integrated circuit applications

An improved equivalent circuit model of a gallium-arsenide (GaAs) MESFET that is optimized for the design and analysis of precision analog integrated circuits is described. These circuits entail different modeling requirements from digital or microwave circuits, for which existing equivalent circuit models are optimized. Improved techniques are presented to model the drain-to-source conductance, device capacitance, and the functional dependence of drain-to-source current.     

Low power impedance measurement integrated circuit for sensor applications

In this paper an integrated circuit for the measurement of the real and imaginary part of an impedance is presented. The circuit is intended for its use in a wireless integrated system. A mixed analog/digital approach has been adopted in order to minimize power and area requirements, as requested by the application. The four electrode configuration is used for impedance measurement using two excitation current sources and a buffer instead of an instrumentation amplifier, therefore reducing the circuit complexity. The digital block controls the working frequency and can compensate the phase error introduced by the analog filters, thereby reducing the total error in the measurement. The integrated circuit has been designed in a CMOS process and it works with 3.3 V with a power consumption of . Experimental results to verify its functionality are presented.     

GaInP/GaAs HBTs for high-speed integrated circuit applications

The use of GaInP/GaAs heterojunction bipolar transistors (HBTs) for integrated circuit applications is demonstrated. The discrete devices fabricated showed excellent DC characteristics with low V_ce offset voltage and very low temperature sensitivity of the current gain. For a non-self-aligned device with a 3-μm×1.4-μm emitter area, f_T was extrapolated to 45 GHz and f_max was extrapolated to 70 GHz. The measured 1/f noise level was 20 dB better than that of AlGaAs HBTs and comparable to that of low-noise silicon bipolar junction transistors, and the noise bump (Lorentzian component) was not observed. The fabricated gain block circuits showed 8.5 dB gain with a 3-dB bandwidth of 12 GHz, and static frequency dividers (divide by 4) were operable up to 8 GHz     

The grating guide—A component for integrated optics

A plane-wave theory for the integrated optics grating guide is presented. The characteristics of the guide are described using the wall reflection coefficient. Calculations are made of the attenuation, minimum-bend radius, and field distribution. Some methods of realizing the grating guide are proposed.     

1 µm MOSFET VLSI technology: Part III—Logic circuit design methodology and applications

Logic circuits were designed and fabricated in a 1 µm silicon-gate MOSFET technology. First, conventional random logic chip images using the largely one-dimensional "Weinberger" layout are examined. The image is able to provide chips with an average circuit delay of 3 ns at the 8000 circuit level of integration. Second, two forms of PLA and PLA-based macros are discussed. A dynamic PLA, used in a microprocessor cross section and including 105 product terms, which achieves a 56 ns cycle time is described. A static PLA, designed for 21- ns delay and achieving measured delays from 13 to 21 ns, is also described. Extensions, particularly into low-temperature operation, are discussed.     

GaAs/AlGaAs heterojunction bipolar transistors for integrated circuit applications

Molecular-beam epitaxy (MBE) and ion implantation were used to fabricate GaAs/AlGaAs heterojunction bipolar transistors with buried wide bandgap emitters. Inverted-mode current gains of ∼ 100 were obtained, demonstrating the feasibility of this technology for I²L types of digital integrated circuits.     

Fully programmable ring-resonator-based integrated photonic circuit for phase coherent applications

A novel ring-resonator-based integrated photonic chip with ultrafine frequency resolution, providing programmable, stable, and accurate optical-phase control is demonstrated. The ability to manipulate the optical phase of the individual frequency components of a signal is a powerful tool for optical communications, signal processing, and RF photonics applications. As a demonstration of the power of these components, we report their use as programmable spectral-phase encoders (SPEs) and decoders for wavelength-division-multiplexing (WDM)-compatible optical code-division multiple access (OCDMA). Most important for the application here, the high resolution of these ring-resonator circuits makes possible the independent control of the optical phase of the individual tightly spaced frequency lines of a mode-locked laser (MLL). This unique approach allows us to limit the coded signal's spectral bandwidth, thereby allowing for high spectral efficiency (compared to other OCDMA systems) and compatibility with existing WDM systems with a rapidly reconfigurable set of codes. A four-user OCDMA system using polarization multiplexing is shown to operate at data rates of 2.5 Gb/s within a 40-GHz transparent optical window with a bit error rate (BER) better than 10/sup -9/ and a spectral efficiency of 25%.     

Advantages of vapor-plated phosphosilicate films in large-scale integrated circuit arrays

The use of low temperature phosphosilicate glass (PSG) films which are compatible with aluminum-metallized integrated circuits, has been found to possess significant merits in LSI applications. PSG used on integrated circuits fabricated in production has resulted in improvements in fabrication yields and device performance and reliability. The properties and effects of PSG which contribute to these benefits have been determined and studied. They include hardness, ability to getter alkali ions, effect on immobile charge density, ability to quench fast states, low stress, resistance to cracking, low pinhole density, and effect on electromigration. The deposition system used to deposit the PSG films and the phosphorus content of the films are also discussed.     

Power integrated circuits—A brief overview

A brief overview of developments in power and high-voltage integrated circuits is presented. The technology can be classified into two types: 1) smart power devices that contain one or more common drain, vertical power transistors with control, and protective circuitry built on the same chip, and 2) high-voltage integrated circuits that combine lateral high-voltage with CMOS logic and analog bipolar circuits on the same chip. These technologies are being aimed at display drivers, telecommunications, motor drives, power supplies, and automotive electronics. A rapid growth in their application in the future can be expected.     

一种用于非制冷红外焦平面阵列的低噪声高均匀性读出电路

提出了一种高均匀性低噪声的读出电路,该电路通过抑制非制冷红外焦平面阵列固定模式噪声,从而可实现高质量的红外图像.该电路前端采用了行共享的增益可控NMOS管抑制像元固定模式噪声,同时采用了新型的相关双采样电路抑制列固定模式噪声.在仿真基础上,采用了AMS 0.35μm CMOS工艺完成了16×16像元芯片的制备.对芯片的大量测试结果表明提出的读出电路可以有效地降低非制冷红外焦平面阵列的固定模式噪声,同时具有高均匀性的特点,适用于高性能非制冷红外探测器.     

Transmission line pulse transformers—Theory and applications

The advent of fast rise-time pulse techniques and their increasing importance brought on by high-speed microminiature circuits and the computer industry has resulted in an increased demand for pulse transformers of various types. The basic idea of constructing transmission line type transformers has been known and used for a number of years. However, such devices have not gained widespread usage, partly because their existence is not well known, but largely because of a lack of basic understanding of their operating principles in terms of elementary fundamentals as well as their capabilities and limitations. The purpose of this paper is twofold. One aim is to develop in step-by-step fashion the basic ideas of transmission line transformers from ordinary transmission line theory. The subject will be approached from the point of view of pulse response rather than ac excitation as is usually the case. Both impedance transformers and balanced-to-unbalanced (balun) transformers, including inverters, will be considered with physical insights into their operation. Several fundamental concepts will be developed and explored in detail (without mathematics), since they have a strong bearing on practical applications. The second purpose is to present new information and pulse measurements which will be useful in the design and applications of such devices, showing their capabilities and hitherto unexplored limitations, as derived from the fundamental concepts. Thus, this paper is partly supplementary to other published work and partly new work with the goal of providing a convenient fundamental understanding of these devices and their inherent potential and shortcomings. Although the intention is not to give a detailed design procedure, some approximate calculations and discussion of significant design criteria are included.     

The current conveyor—A new circuit building block

A new circuit concept applicable to a basic building block in a variety of instrumentation and communication systems is introduced. The new concept is called current conveying and its implementation a current conveyor.     

Generation-recombination noise in semiconductors—The equivalent circuit approach

Generation-recombination noise in semiconductors in thermal equilibrium is treated from the standpoint of thermal fluctuations in equivalent electrical circuits. For the general volume recombination model, a method based on network reduction is presented which allows one to calculate the spectral density of the electron and hole fluctuations without solving for the spectra of the fluctuations in occupancy of the recombination centers and traps. The method is extended to a surface recombination model, thereby avoiding the ambiguities found in previous formal treatments. It is shown that the concept of ambipolar diffusion, the location and spectral density of the random sources, and the spatial correlation of Fourier coefficients of carrier density fluctuations all have simple significance in electrical terms. Using transmission line techniques, the generation-recombination (GR) spectrum is calculated for a two-level semiconductor where recombination occurs at opposite plane surfaces. This new result is examined in detail for the limiting cases approached when the recombination process is 1) volume-limited, 2) surface-limited, and 3) diffusion-limited. It is shown that in the first two cases, the spectrum is identical with that obtained from a zero-dimensional analysis provided the time constant is properly defined. For the diffusion-limited case, however, the spectrum varies as 1/ω^3/2at high frequencies, and at low frequencies the noise is 5/6 that predicted by the simple theory. The new result is shown to compare favorably with measurements reported previously by Hill and van Vliet.