Oscillations have been obtained at frequencies from 100 to 712 GHz in InAs/AlSb double‐barrier resonant‐tunneling diodes at room temperature. The measured power density at 360 GHz was 90 W cm−2, which is 50 times that generated by GaAs/AlAs diodes at essentially the same frequency. The oscillation at 712 GHz represents the highest frequency reported to date from a solid‐state electronic oscillator at room temperature.

Oscillations up to 712 GHz in InAs/AlSb resonant‐tunneling diodes

Several research groups have been actively pursuing antimonide-based electronic devices in recent years. The advantage of narrow-bandgap Sb-based devices over conventional GaAs- or InP-based devices is the attainment of high-frequency operation with much lower power consumption. This paper will review the progress on three antimonide-based electronic devices: high electron mobility transistors (HEMTs), resonant tunneling diodes (RTDs), and heterojunction bipolar transistors (HBTs). Progress on the HEMT includes the demonstration of Ka- and W-band low-noise amplifier circuits that operate at less than one-third the power of similar InP-based circuits. The RTDs exhibit excellent figures of merit but, like their InP- and GaAs-based counterparts, are waiting for a viable commercial application. Several approaches are being investigated for HBTs, with circuits reported using InAs and InGaAs bases.

Antimonide-based compound semiconductors for electronic devices: A review

We describe active and nonlinear wave propagation devices for generation and detection of (sub)millimeter wave and (sub)picosecond signals. Shock-wave nonlinear transmission lines (NLTL's) generate /spl sim/4-V step functions with less than 0.7-ps fall times. NLTL-gated sampling circuits for signal measurement have attained over 700-GHz bandwidth. Soliton propagation on NLTL's is used for picosecond impulse generation and broadband millimeter-wave frequency multiplication. Picosecond pulses can also be generated on traveling-wave structures loaded by resonant tunneling diodes. Applications include integration of photodetectors with sampling circuits for picosecond optical waveform measurements and instrumentation for millimeter-wave waveform and network (circuit) measurements both on-wafer and in free space. General properties of linear and nonlinear distributed devices and circuits are reviewed, including gain-bandwidth limits, dispersive and nondispersive propagation, shock-wave formation, and soliton propagation. >

Active and nonlinear wave propagation devices in ultrafast electronics and optoelectronics

The GaAs nonlinear transmission line (NLTL) is a monolithic millimeter-wave integrated circuit consisting of a high-impedance transmission line loaded by reverse-biased Schottky contacts. The engineering of functional monolithic NLTLs is considered. Through generation of shock waves on the NLTL, the authors have generated electrical step functions with approximately 5 V magnitude and less than 1.4 ps fall time. Diode sampling bridges strobed by NLTL shock-wave generators have attained bandwidths approaching 300 GHz and have applications in instruments for millimeter-wave waveform and network measurements. The authors discuss the circuit design and diode design requirements for picosecond NLTL shock-wave generators and NLTL-driven sampling circuits. >

GaAs nonlinear transmission lines for picosecond pulse generation and millimeter-wave sampling

This paper describes a new high-density low-power circuit approach for implementing static random access memory (SRAM) using low current density resonant tunneling diodes (RTDs). After an overview of semiconductor random access memory architecture and technology, the concept of tunneling-based SRAM (TSRAM) is introduced. Experimental results for a compound semiconductor 1-bit 50-nW TSRAM gain cell using low current density (/spl sim/1 A/cm/sup 2/) RTDs and low-leakage heterostructure field effect transistors are presented. We describe a one-transistor TSRAM cell which could convert silicon dynamic RAM (DRAM) to ultradense SRAM if an ultralow current density (/spl sim/1 /spl mu/A/cm/sup 2/) silicon bistable device is developed. Finally, we present experimental and simulation results for a TSRAM cell using multipeaked I-V curve devices and a multivalued word line. This approach aims at increasing storage density through vertical integration of bistable devices such as RTD's.

Tunneling-based SRAM

Rise times for simple pulse‐forming circuits are presented. Switching times for present best devices are in the range of 5–15 ps. An equivalent circuit model for resonant tunneling diodes inclusive of space‐charge effects and transit time effects in the depletion region is presented. From these models it is shown that switching times are limited by the device RC time constants and are relatively unaffected by the resonant state lifetime or depletion layer transit times. Appropriate figures of merit for switching applications are the device capacitance and peak current density. Less emphasis should be placed on improving the peak‐to‐valley ratio. Optimally designed devices which maximize the current density should be capable of switching in under 5 ps.

Resonant tunneling diodes for switching applications

Voltage waveforms with 6 V amplitude and 1.6 ps fall time were generated by voltage shock‐wave formation on a hyperabrupt‐doped Schottky diode monolithic GaAs nonlinear transmission line.

Hyperabrupt‐doped GaAs nonlinear transmission line for picosecond shock‐wave generation

It is shown that nonlinear wave propagation on a monolithic GaAs nonlinear transmission line can form shock waves with fall time as short as 3.5 ps. An output fall time of 4.3 ps was measured for a single line driven at 15 GHz (20-ps fall time) while a cascade of two lines driven at 8 GHz (37-ps fall time) produced a 2-V wavefront with 3.5-ps fall time. >

Generation of 3.5-ps fall-time shock waves on a monolithic GaAs nonlinear transmission line

Picosecond electrical transients were generated by shockwave formation on a GaAs monolithic nonlinear transmission line An output fall time of 78 ps was generated by a single line driven at 15 GHz (20 ps input fall time), while 37:1 compression to 101 ps was attained for two cascaded lines

Generation of 7.8 ps electrical transients on a monolithic nonlinear transmission line

Picosecond pulse generators are central components for high-speed electronic instrumentation. Step-recovery diodes generate ~10-V transitions of 35-ps rise time, while funnel diodes generate ~0.2-V 25-ps transitions. We report generation of electrical wavefronts with 7.8-ps fall time by propagation1,2 on a GaAs monolithic nonlinear transmission line.

Y. C. Pao

Papers

Resonant tunneling diodes for switching applications

Hyperabrupt‐doped GaAs nonlinear transmission line for picosecond shock‐wave generation

Generation of 3.5-ps fall-time shock waves on a monolithic GaAs nonlinear transmission line

Generation of 7.8 ps electrical transients on a monolithic nonlinear transmission line

Generation of 7.8-ps electrical transients on a monolithic nonlinear transmission line