Charge transport by surface acoustic waves in GaAs

Abstract

The traveling wave potential wells, associated with a surface acoustic wave (SAW) generated in a multilayer epitaxial GaAs structure, are used to transport electrons at the velocity of sound in the buried channel formed by a Schottky-N-P layer configuration. A monolithic delay line based on the SAW transport concept is constructed and the time domain response of the delay line is presented. The SAW charge transport concept in GaAs is expected to be useful for the implementation of high-speed monolithic signal processors.

Focusing of surface-acoustic-wave fields on (100) GaAs surfaces

“…While the initial SAW applications mainly included electronic signal processing devices based on strong piezoelectric materials, nowadays several alternative applications have been proposed that explore modulation of the optical properties and the acoustically induced transport of carriers by the SAW fields in semiconductors. 4,5 There has been renewed interest in SAWs since the demonstration that they can be applied to dynamically modulate the electronic properties of GaAs-based low-dimensional semiconductor structures like photonic crystals, 6 microresonators, 7,8 quantum wells, 9-11 quantum wires, 12 and quantum dots. 13 The traveling SAW fields in these structures have been used to transport electron-hole pairs 9,12,14 and spin excitation.…”

Embedded interdigital transducers for high-frequency surface acoustic waves on GaAs

“…Equation (1) indicates that reflection effects become significant, when L IDT is comparable to the effective scattering length L eff =1/͑␣ + r͒. Equation (2) expresses the fact that in a long IDT only a section of maximum length L eff contributes to P͑L IDT ͒, delivering an acoustic power P max = ͓gL eff ͔ 2 .…”

“…A SAW Rayleigh propagating along a ͗110͘ direction of the (001) GaAs substrate surface has nonvanishing strain components u xx = ‫ץ‬u x / ‫ץ‬x and u zz = ‫ץ‬u x / ‫ץ‬x, and u xz = 1 2 ͑‫ץ‬u x / ‫ץ‬z + ‫ץ‬u z / ‫ץ‬x͒ 0. In these expressions, u denotes the SAW displacement field, and the coordinate system ͑x , y , z͒ is defined in Fig.…”

The Application of Surface Acoustic Waves in Surface Semiconductor Investigations and Gas Sensors

“…Piezoelectric-semiconductor structure for investigation of acoustoelectric interactions [35] The electrical and electronic semiconductor surface properties may be determined by means of such parameters as: the surface potential, the carrier trapping velocity by fast and slow energetic surface states, the type of impurities of atoms and molecules, their concentration and location in the energy bandgap in the target material, as well as by the surface mobility of carriers and the lifetime of majority and minority carriers, the velocity of carriers trapping into surface states in semiconductor, and the effective live time of electrical carriers in fast surface states [36][37][38][39].…”

“…The special electrical and electronic InAs properties arise mainly from the very high mobility of carriers, makeing it possible to construct electronic devices in very high frequency ranges. Applying the galvanomagnetic effect in InAs the hallotrons and gaussotrons were constructed [36]. This material is also often used in various sensors applications [6,40].…”