Eric Joseph Wildi

n-channel lateral insulated gate transistors: Part I—Steady-state characteristics

The basic physics of the steady-state characteristics of the lateral insulated gate transistor (LIGT) is discussed. Results from a tWo-dimensional computer simulation Of representative LIGT structures are presented. Several Structural and process enhancements to the basic LIGT structure to increase the current handling capability and suppress latchup are pointed out. Experimental results of the steady-state characteristics of a variety of LIGT test structures are presented and analyzed. The static latching aspect of LIGT is discussed insome detail. LIGT devices employing either a buried layer or surface shorts are shown to current limit rather than latching up.

Lateral insulated gate transistors with improved latching characteristics

Lateral insulated gate transistors (LIGTs) were fabricated to study their applicability for power integrated circuits. Three independent techniques for improving LIGT latching current are described in this paper. Devices that latch at 510 A/cm2have been fabricated; devices that current-limit at 475 A/cm2without latching have also been demonstrated.

New high voltage IC technology

This paper describes a new 500 volt junction isolated BIMOS technology developed by and recently brought into production at the General Electric Company. It differs from previously reported junction isolated (J.I.) high voltage IC (HVIC) technologies in the versatility and ruggedness is provides. As such, it not only addresses the display driver markets, but also those dealing with power conditioning and control.

500V BiMOS technology and its applications

The 500V junction-isolated BiMOS high voltage IC process technology recently introduced by the General Electric Company(1,2) and now in manufacturing production provides the circuit designer with a myriad of low and high voltage devices. However, to exploit the full capability of this process and apply it efficienty, it is crucial to understand and model the devices it makes available. This paper describes specifically the high voltage NPN structure, its resulting equivalent model, and shows actual device data. HSPICE device models that accurately predict the behavior of low voltage components (which may be referenced at high voltages) as a function of temperature have been developed and will be presented. We will conclude by showing generic application examples that convey the flexibility and power of this process.

Dynamics and Limitations of Blood/Muscle Interface Detection Using Doppler Power Returns

A new method that relies on backscattered Doppler power from red cells to locate and track blood/muscle interfaces is described. It allows current pulsed Doppler flowmeter systems to yield continuous information on internal vessel diameter and to evenly distribute range gates within the lumen. A smal signal model is fommulated that describes this feedback approach and indicates the relationships between system parameters (filter characteristics, gain settings, sampling rate, etc.) and tracking dynamics. Large signal nonlinear effects, problems of initial lock-in, potential loss of lock, and sources of tracking error are then outlined to provide a thorough description of this novel technique.

Design of Current Sensors in IGBT's

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 current sensor (or pilot) and the emitter of this small IGBT is connected to ground via a resistor. As the voltage at the emitter of the current sensor increases due to increasing current flow, the forward drop across the current sensor decreases and the ratio between the main current and the sensor current decreases. Experimentally, the dependence of the normalized current sensor (or pilot) voltage on the main IGBT current of a 500-V, n-channel, asymmetric IGBT has been shown to be fairly linear, except when a small main current or a large pilot resistor is used. The main-to-pilot current ratio increases with increasing carrier lifetime and increasing distance from the main IGBT. >

Multi-chip modules for analog and microwave: DC to 18 GHz

Multichip modules are considered, with particular emphasis on the implementation of devices in the high density interconnect (HDI) process. A digital 128*128 GaAs crossbar switch in HDI that operates at 400 MHz is considered. Results of measurements on a 3.6-cm-long by 243- mu m-wide microstrip transmission line demonstrate that -1.3-dB insertion and -30-dB return loss can be achieved for frequencies up to 18 GHz with HDI technology. Also considered is a C-band 6-GHz transmit/receive (T/R) HDI module that uses impedance-matched interconnects, exhibits no out-of-band oscillations, and results in a 40% size reduction compared to a conventional chip-and-wire counter-part using the same monolithic microwave integrated circuits. In addition, HDIs unique features allowed the construction of an 82-component voice processor/modem. It is pointed out that preliminary work shows the feasibility of a 10-A 50-W point-of-load 50-V-to-5-V DC-to-DC power supply for distributed applications.<<ETX>>

High voltage pullup devices in a BiMOS HVIC technology

High-voltage complementary pullup and pulldown devices have been fabricated in a high-voltage integrated circuit process that is based on thin epitaxial layers (<10 mu m). The device structures described allow high-voltage pullup devices to be realized where normally only pulldown devices would be possible in such thin epitaxial layers. Only one additional mask was needed to incorporate these devices into the existing junction-isolated BiMOS technology. A 400-V chip featuring in high-voltage, low-power consumption drivers along with 5-V CMOS logic has been fabricated using novel depletion-mode NMOS design.<<ETX>>

A 500V/25A half-bridge IC with on-chip control logic

This paper will describe a 500V junction-isolated BiMOS tecnology developed to produce a 500V/25A half bridge for power control. System architecture aspects and performance driving capacitive, resistive and inductive loads (dV/dt > 300V/μs and (di/dt ∼ 200A/μs) will be discussed.