Effects of Pressure on GaAs/InxGa1-xAs/AlAs Resonant Tunneling Structures

doi:10.18494/sam.2009.525

Abstract

Highlights

In recent years, with rapid developments in molecular beam epitaxy (MBE) and metallorganic chemical vapor deposition (MOCVD) and the technologies of etching methods, many types of quantum well material can be grown and fabricated.(1–3) A resonant tunneling diode (RTD) is an example of such quantum well material with a negative differential resistance (NDR) effect on the current-voltage (I-V) characteristics, and it has been widely used in electronic and photonic devices over the last decade
For GaAs/ InxGa1–xAs/AlAs double-barrier resonant tunneling structures (DBRTSs), the I-V curves will change under external stress; the well-known effects are as follows: energy band gap variation with hydrostatic pressure, stress-induced piezoelectric field in III-V compound semiconductors, change in the band edge curvature, and band edge splitting with uniaxial pressure.(13) These effects have been used for designing novel sensors.(14,15)
GaAs/InxGa1–xAs/AlAs thin films are grown by MBE on a [001]-oriented GaAs semi-insulating substrate, and the RTS is fabricated with an air-bridge structure

Summary

Introduction

With rapid developments in molecular beam epitaxy (MBE) and metallorganic chemical vapor deposition (MOCVD) and the technologies of etching methods, many types of quantum well material can be grown and fabricated.(1–3) A resonant tunneling diode (RTD) is an example of such quantum well material with a negative differential resistance (NDR) effect on the current-voltage (I-V) characteristics, and it has been widely used in electronic and photonic devices over the last decade. Pressure or stress plays a very important role in the investigation of the transport properties of semiconductor materials and offers a possibility of designing heterostructure devices with customized performances.(11,12) All III-V compounds are piezoelectric owing to the polar character of the bonds between their different atoms. For GaAs/ InxGa1–xAs/AlAs double-barrier resonant tunneling structures (DBRTSs), the I-V curves will change under external stress; the well-known effects are as follows: energy band gap variation with hydrostatic pressure, stress-induced piezoelectric field in III-V compound semiconductors, change in the band edge curvature, and band edge splitting with uniaxial pressure.(13) These effects have been used for designing novel sensors.(14,15). We discuss the measurements of the static uniaxial stress applied on a GaAs/InxGa1–xAs/AlAs resonant tunneling structure (RTS) along the [110] and directions. The 10–9 Pa–1 mesopiezoresistive sensitivity indicates that these structures can be used for designing highsensitivity sensors, and its frequency output characteristics (approximately –17.9 kHz/ MPa) imply its potential applications under half-digital conditions

Methods

Results

Conclusion