US 5,514,626 A · Method for reducing heterostructure acoustic charge transport device saw drive power requirements

Abstract

A HACT device employing a thin-film overlay of a more strongly piezoelectric material can operate as a delay line and as a tapped delay line, or transversal filter, while requiring less total power for the SAW clock signal. The increased electrical potential per unit total SAW power thus realized facilitates coupling between the total SAW energy and the mobile charge carriers. Some materials systems, such as a GaAs substrate and a ZnO thin-film overlay, will require an intervening thin-film dielectric layer in between the HACT substrate and epitaxial layers and the thin-film piezoelectric overlay. This may be necessitated by chemical, semiconductor device processing, or adhesion incompatibilities between the substrate material and the thin-film overlay material.

Claims21

Dependent claims

A method for increasing the charge carrying capacity of a charge transport device, said method comprising steps of:

providing a semiconductor substrate having a surface;
fabricating a surface acoustic wave transducer along said surface, said surface acoustic wave transducer having an aperture for emitting surface acoustic waves;
providing a channel including epitaxal layers of semiconductor material along side surface, said channel disposed adjacent said aperture to allow illumination of said channel by said surface acoustic waves;
disposing a first nondestructive sensing electrode on said channel, said first nondestructive sensing electrode having an associated first element factor;
depositing a layer of dielectric material atop said channel and said first nondestructive sensing electrode;
and
disposing a second nondestructive sensing electrode atop said layer of dielectric material.

4 more elements

Dependencies are inferred from the claim text.

Method for reducing heterostructure acoustic charge transport device saw drive power requirements

Life of this patent

Method for reducing heterostructure acoustic charge transport device saw drive power requirements

Life of this patent

Abstract

Claims21