Heterostructure acoustic charge transport device having electron and hole transport

An electrical circuit comprising:

• an acoustic charge transport device including
• a transducer means fabricated on a surface of a gallium arsenide structure for launching along a propagation axis surface acoustic waves having a wavelength and a frequency and characterized by maxima and minima of electrical potential which transport both electrons and electrical "holes" provided thereto;
• a first electrode means for providing electrical "holes" to said gallium arsenide structure;
• a second electrode means spaced along said propagation axis approximately one half said surface acoustic wavelength, for providing electrons to said gallium arsenide structure
• a transport channel in said gallium arsenide structure having a major dimension extending parallel to said propagation axis characterized by an intrinsic vertical electrical potential for providing lateral and vertical confinement of both electrons and electrical "holes" presented thereto for transport by said surface acoustic waves;
• a third electrode means for providing signals to modulate said propagating electrons and electrical "holes";
• a fourth electrode means configured with said transport channel at an end thereof distal to said transducer means for providing an electrical signal equivalent of said modulated propagating electrons and electrical "holes";
• said gallium arsenide structure fabricated in accordance with the steps of
• growing a first layer of aluminum gallium arsenide on a gallium arsenide substrate;
• growing a first layer of gallium arsenide on said aluminum gallium arsenide layer;
• growing a second layer of aluminum gallium arsenide on said first layer of gallium arsenide;
• doping said second layer of aluminum gallium arsenide;
• said second layer of aluminum gallium arsenide being doped to provide electrical charge to satisfy uncompensated surface states in said first gallium arsenide layer;
• and
• an electrical means for sampling signals from said fourth electrode means at a rate approximately equal to twice said surface acoustic wave frequency.

An acoustic charge transport device comprising:

• a first transducer means fabricated on a surface of a gallium arsenide structure for launching along a propagation axis surface acoustic waves having a wavelength and a frequency and characterized by maxima and minima of electrical potential which transport electrons and electrical "holes" provided thereto;
• a first electrode means for providing electrical "holes" to said gallium arsenide structure;
• a second electrode means spaced along said propagation axis approximately one half said surface acoustic wavelength, for providing electrons to said gallium arsenide structure;
• a first transport channel in said gallium arsenide structure having a major dimension extending parallel to said propagation axis characterized by an intrinsic vertical electrical potential for providing lateral and vertical confinement of electrical "holes" presented thereto for transport by said surface acoustic waves;
• a second transport channel in said gallium arsenide structure having a major dimension extending parallel to said propagation axis characterized by an intrinsic vertical electrical potential for providing lateral and vertical confinement of electrons presented thereto for transport by said surface acoustic waves;
• a third electrode means for providing signals to modulate said propagating electrons and electrical "holes";
• a fourth electrode means configured with said transport channel at an end thereof distal to said transducer means for providing an electrical signal equivalent of said modulated propagating electrons and electrical "holes";
• said gallium arsenide structure fabricated in accordance with the steps of:
• growing a first layer of aluminum gallium arsenide on a gallium arsenide substrate;
• growing a first layer of gallium arsenide on said aluminum gallium arsenide layer;
• growing a second layer of aluminum gallium arsenide on said first layer of gallium arsenide;
• doping said second layer of aluminum gallium arsenide;
• growing a second layer of gallium arsenide on said second aluminum gallium arsenide layer;
• growing a third layer of aluminum gallium arsenide on said second layer of gallium arsenide;
• doping said third layer of aluminum gallium arsenide;
• said second and third layers of aluminum gallium arsenide being doped to provide electrical charge to satisfy uncompensated surface states in said first and second gallium arsenide layers;
• said first electrode means configured to electrically contact said first layer of gallium arsenide but not said second layer of gallium arsenide and second electrode means configured to electrically to contact said second layer of gallium arsenide but not said first layer of gallium arsenide.

An electrical circuit, comprising:

• an acoustic charge transport device comprising:
• a first transducer means fabricated on a surface of a gallium arsenide structure for launching along a propagation axis surface acoustic waves having a wavelength and a frequency and characterized by maxima and minima of electrical potential which transport electrons and electrical "holes" provided thereto;
• a first electrode means for providing electrical "holes" to said gallium arsenide structure;
• a second electrode means spaced along said propagation axis approximately one half said surface acoustic wavelength, for providing electrons to said gallium arsenide structure;
• a first transport channel in said gallium arsenide structure having a major dimension extending parallel to said propagation axis characterized by an intrinsic vertical electrical potential for providing lateral and vertical confinement of electrical "holes" presented thereto for transport by said surface acoustic waves;
• a second transport channel in said gallium arsenide structure having a major dimension extending parallel to said propagation axis characterized by an intrinsic vertical electrical potential for providing lateral and vertical confinement of electrons presented thereto for transport by said surface acoustic waves;
• a third electrode means for providing signals to modulate said propagating electrons and electrical "holes";
• a fourth electrode means configured with said transport channel at an end thereof distal to said transducer means for providing an electrical signal equivalent of said modulated propagating electrons and electrical "holes";
• said gallium arsenide structure fabricated in accordance with the steps of:
• growing a first layer of aluminum gallium arsenide on a gallium arsenide substrate;
• growing a first layer of gallium arsenide on said aluminum gallium arsenide layer;
• growing a second layer of aluminum gallium arsenide on said first layer of gallium arsenide;
• doping said second layer of aluminum gallium arsenide;
• growing a second layer of gallium arsenide on said second aluminum gallium arsenide layer;
• growing a third layer of aluminum gallium arsenide on said second layer of gallium arsenide;
• doping said third layer of aluminum gallium arsenide;
• said second and third layers of aluminum gallium arsenide being doped to provide electrical charge to satisfy uncompensated surface states in said first and second gallium arsenide layers;
• said first electrode means configured to electrically contact said first layer of gallium arsenide but not said second layer of gallium arsenide and second electrode means configured to electrically to contact said second layer of gallium arsenide but not said first layer of gallium arsenide;
• and
• an electrical means for sampling signals from said fourth electrode means at a rate approximately equal to twice said surface acoustic wave frequency.