Low temperature multi-differential operational amplifier

Because of the application of field-effect transistors, and integrated circuits in space electronic systems and the fact that proton irradiation data at energies typical of a space environment are not extensive, an experimental evaluation of these devices has been conducted. Thee important electrical parameters of these devices were measured before, during, and after irradiation at the Oak Ridge National Laboratory's 22-Mev Cyclotron. The results obtained from the MOS field-effect study show that their degradation processes include that of charge storage in the silicon dioxide insulating layer and radiation-induced changes in surface states. MOS transistors have been found to degrade at orders of magnitude less integrated proton flux than many bipolar and junction field-effect transistors; therefore, for space applications in radiation fields such as Van Allen Belts and solar particle events, these devices may be subject to serious radiation damage. The junction field-effect transistor desplays a large initial spread in device irradiation response. However, it appears to possess a high degree of resistance to proton irradiation. The integrated circuits tested were of the monolithic type and under proton irradiation displayed a large reduction of minority carrier lifetime in the base region of the circuit transistors. Other less important defects are reduction of free carrier concentration and reduction in mobility. Important electrical parameters that are affected by radiation are imput threshold voltages, output low level voltages, leakages currents, and transient characteristics. In conclusion, MOS field-effect transistors and integrated circuits display significant damage characteristics when subjected to a space proton environment.

Further comments on "Comparison of the neutron radiation tolerance of bipolar and junction field effect transistors"

High-precision, resistor less gas pressure sensor and instrumentation amplifier in CNT technology

Chapter 7 - Solid State Voltage Amplifiers

Bipolar Junction and Junction Field-Effect Transistors

We have developed technology and construction solutions system to increase differential pairs (DP) of JFet with p- and n-channels identity, which are included into silicon complementary bipolar process of SPE “Pulsar” (Moscow). The possibility of creating several types of JFet DPs within the process is shown. The paper presents the results of experimental studies of two types of DP JFet designs with p- and n-channels for the spread of gate-source voltage ΔVGS depending on the drain current and drain-source voltage. The main features of the first design of p-channel JFets were the following: formation of drain/source area due to passive base of npn-transistor and deep collector areas for pnp-transistor; channel formation based on p-layer collector of pnp-transistor; formation of bottom gate using p+ buried layer; top gate formation due to active base and polysilicon emitter of npn-transistor. A feature of the second JFet design was top gate formation due to passive base. The designs of the first and second types of n-channel Jfet were formed similarly, taking into account the replacement of the applied areas of bipolar transistors with opposite ones in the type of conductivity. It was found that with increasing drain current ΔVGS decreases, and with increasing drain-source voltage ΔVGS at high currents increases for DP based on p-channel JFet with the first type of design. The maximum difference ΔVGS was in the range of 5–80 mV for a given differential pair JFet with a p-channel. On plots for DP p-channel JFet with the second type design a significantly lower voltage spread ΔVGS was shown: for example, for the drain current ID = 50 μA the voltage spread ΔVGS did not exceed 10 mV. In this case the voltage spread ΔVGS practially did not depend on drain-source voltage in contrast to differenctial pair of the first type. The second type JFet n-channel differential pairs like for the DP p-channel JFet provided lower spread values in comparison with the first type design: ΔVGS reached values of 5-20 mV. Moreover, for the design of the second type, a significantly weaker effect of the drain-source voltage on ΔVGS was observed at high current densities. The developed designs of differential pairs based on p- and n-channel JFet are recommended for use in organizing the production of CBiCJFet analog circuits, including operations at low temperatures.

An analysis of temperature-induced transient noise for a thermal detector prepared with Pb(Zr, Ti)O3-Pb(Sb0.5Nb0.5)O3 (PZT-PSN) pyroelectric ceramics as the sensing element is conducted by measuring its oven noise as a function of the junction field-effect transistor (JFET) characteristics, gate resistance, low-temperature heat treatment, chemical composition and the grain size of the pyroelectric ceramic. Pyroelectric wafers are prepared by the mixed oxide technique, and thermal sensors are fabricated with a PZT-PSN ceramic wafer, JFET, chip-type gate resistor, alumina PCB (printed circuit board) and a TO-5 package with antireflective (AR)-coated Si window. Thermal detector noise depends on the chemical composition of the pyroelectric sensing element. The temperature-induced transient JFET noise varies with its characteristics and gate resistance and is reduced by connecting a pyroelectric sensing element with high capacitance. The pyroelectric ceramic sensing element generates burst noise in the region from 7 to ?10°C during cooling, which is remarkably reduced by reducing the grain size of the pyroelectric ceramic and/or by cyclic heat treatment at a low temperature. Thus, burst noise has a strong relationship with the elastic energies within the ceramic sensing element and the bonding material between the sensing wafer and the PCB, originating in the different thermal expansion between pyroelectric sensing wafer and alumina PCB.

Improvement of single event effects in InP-based HEMT with a composite channel of InGaAs/InAs/InGaAs

Methods for extracting threshold-voltage shift (DeltaV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) in high-kappa transistors using the single-pulse drain current-gate voltage (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ) technique were compared with respect to their accuracies and limitations. It is concluded that an accurate estimation of the (DeltaV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) caused by charge trapping in high-kappa dielectrics can be obtained from the hysteresis of the pulsed (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ) curve with proper calibration of the pulse measurement to account for the propagation delay. The (DeltaV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) extraction that is based on the decrease of drain current during a pulse tends to underestimate charge trapping for higher pulse amplitudes.

This paper describes a new instrumentation amplifier (IA) that has the ability to operate in all four possible modes: voltage, current, transimpedance, and transadmittance mode using a single Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA) along with external grounded resistors. The suggested IA structures offer a broad range of common mode rejection ratio bandwidth (BW) and differential gain bandwidth of around (18.7 MHz, 26 MHz) for voltage mode, (17.29 MHz, 1.05 GHz) for current mode, (25.25 MHz, 168 MHz) for transimpedance mode and (17.29 MHz, 1.05 GHz) for transadmittance mode respectively, in which an unreported finding of 1.05 GHz gain BW underscores the uniqueness of the designs. Additionally, they are suitable for IC integration due to the available grounded passive attributes. Moreover, the designs come with an interesting feature for electronically tuning the gains via biasing current (IB) and also have a low power dissipation. Realization of DVCCTA uses 20 MOS transistors, and OrCAD PSPICE with a 0.18 μm TSMC CMOS technology parameter is used to authenticate the workableness of the proposed IA circuits. The performance of the suggested topologies is analyzed by considering the non‐idealities of the DVCCTA. Apart from that, process, voltage, temperature‐dependent variations and Monte Carlo simulations are also delineated for the verification of the proposed designs. The functionality of the circuits has also been validated through practical experimentation, employing commercially accessible current feedback operational amplifiers, such as the ICAD844 and post layout simulations. The simulation results correlate well with the theoretical prediction.

A simple technique to measure the minority carrier mobility using a bipolar junction transistor is demonstrated. By fixing the base-emitter voltage, the carrier injection into the base is constant. The collector current is then monitored as a function of a magnetic field applied perpendicular to the current transport across the base. The magnetic field leads to an increase in base transit time and a corresponding decrease in collector current. From the resulting fractional change in collector current, the minority carrier mobility in the base can be determined. For narrow base transistors, quasiballistic transport across the base must be taken into account when determining the bulk minority carrier mobility.

Noise in Solid State Devices

&lt;div class="htmlview paragraph"&gt;A fundamental knowledge of solid-state physics is used to gain understanding of the two basic active solidstate devices-bipolar and field-effect transistors. The bipolar transistor is treated as two junctions communicating through a common region (the base). The functions of charge injection and collection are studied and developed to explain the observed static (d-c) volt-ampere characteristics. Major bipolar-transistor parameters are then reviewed. Finally, the limitations in gain, voltage, and power are discussed. There are basically two forms of field-effect transistors: the junction field effect transistor (JFET) and the metal oxide semiconductor (MOS). Both forms use a voltage applied to a gate electrode or region to control charge (current) flow between source and drain terminals. This action is studied and used to to develop the observed state (d-c) volt-ampere characteristic. The major field-effect transistor parameters are then reviewed. Finally, the limitations in gain, voltage, and power are discussed. Included in the appendixes is a brief review of transistor evolution, which serves as an introduction to device processing information, and an introduction to some of the lesser known solid-state devices. A third appendix explains thermal resistance.&lt;/div&gt;

For their function junction field effect transistors (JFETs) depend on reverse-biased junction depletion regions that control majority carrier conduction in thin channels between ohmic contacts to source and drain regions. The structures require fewer masking steps and fewer diffusions than bipolar transistors and may be made either n channel or p channel. The contact through which the majority carriers enter the channel is termed the source S, and the exit is the drain D. The circuit symbol and some characteristics for an n channel FET are shown in Fig. 6.1. A MESFET is similar except that the junction is a metal-semiconductor barrier. MOSFETs (metal-oxide-semiconductor FETs) are considered in Chap. 7.

: Gallium nitride high electron mobility transistors are attractive to the DoD for their ability to operate at high frequencies, voltages, temperatures, and power. Yet, there are concerns about the reliability of these devices. Various degradation mechanisms and their causes are proposed in the literature. A variety of reliability tests were conducted to understand these mechanisms and causes. A multi-stressor experiment revealed different failure mechanisms than are in the literature. In particular, the devices tested at high voltage in the OFF state did not degrade significantly as suggested by others' reports. The validity of temperature-accelerated life testing when applied to GaN HEMT lifetime assessments is questioned. Temperature alone could not explain the differences in observed degradation. The tested devices showed excellent robustness to high forward gate stress, exhibiting only a slight change in gate diode characteristic, little decrease in maximum drain current, and a persisting breakdown voltage exceeding 200 V. The time-dependence of degradation was analyzed, and results of continuous- and pulsed-direct current stressing were compared.