Integrated scanning tunneling microscope

An integrated scanning tunneling microscope comprising:

• a substrate;
• a piezoelectric bimorph cantilever attached to said substrate at one end and with the other end having a protruding, conductive tip formed thereon, said tip terminating in a point, said bimorph further comprising two layers of piezoelectric material sandwiched between multiple pairs of electrodes in such a manner that three axis movement of said bimorph is caused by applying suitable potentials to said multiple pairs of electrodes;
• a conducive surface;
• means for holding said conductive surface within the region of spatial overlap of the probability density function for the electrons of the atoms in said tip and the electrons of the atoms of said conductive surface;
• bias means for applying a bias potential between said tip and said conductive surface sufficient to cause tunneling current to flow between said tip and said conductive surface;
• control means coupled to said bias means and coupled to said multiple pairs of electrodes for sensing the magnitude of the tunneling current flow and for adjusting the potentials applied between the appropriate pair or pairs of said electrodes so as to move said tip in a manner to stabilize said tunneling current;
• wherein said means for holding said conductive surface close to said tip is a second substrate having a cavity formed therein and having said conductive surface in said cavity, said second substrate attached to said substrate so as to place said cavity over said bimorph such that said bimorph has room to move in all three axes and such that said conductive surface is held close to said tip such that the motion of the said bimorph is sufficient to bring said tip within tunneling range of the said conducting surface.

An integrated apparatus comprising:

• a semiconductor substrate;
• an integrated bimorph cantilever having first and second ends, said first end attached to said substrate and having a tip at each second end, said tip having a point, said bimorph comprising:
• a first conductive layer patterned into a plurality of electrodes including means for charging each electrode with different electrical potentials;
• a first layer of piezoelectric material formed over said first conductive layer;
• a second conductive layer formed over said first layer of piezoelectric material to form a center electrode;
• a second layer of piezoelectric material formed over said second conductive layer;
• and
• a third conductive layer formed over said second layer of piezoelectric layer patterned into a plurality of electrodes aligned with said plurality electrodes patterned in said first conductive layer;
• a conductive surface;
• means coupled to said substrate for holding said conductive surface within a region such that the movement of said bimorph is sufficient to bring the tip within tunneling range of said conducting surface;
• control means integrated on said substrate and coupled to said tip, said conductive surface and said electrodes of said bimorph cantilever for providing a bias voltage between said tip and said conductive surface, and for measuring the current flowing between said tip and said conductive surface, and for causing the appropriate voltages to be applied between the appropriate pairs of electrodes to cause said tip to move in an appropriate manner so as to maintain a desired tunneling bias current.

An integrated scanning tunneling microscope comprising:

• a substrate;
• a piezoelectric bimorph motion transducer attached to said substrate, and having an end cantilevered in free space and having a protruding, conductive tip formed thereon, said tip terminating in a point where said tip has the physical shape, orientation and size characteristic of an integrated tip structure formed by evaporation of conductive material through a shadow mask formed of mask material having an aperture aligned over said cantilevered end using integrated circuit manufacturing techniques, said motion transducer including a plurality of pairs of electrodes for receiving signals to cause said motion transducer to move;
• a conductive surface;
• means for holding said conductive surface such that the movement of said motion transducer is sufficient to bring said tip within tunneling range of said conductive surface;
• bias means for applying a bias potential between said tip and said conductive surface sufficient to cause tunneling current to flow between said tip and said conductive surface;
• control means coupled to said bias means and coupled to said plurality of pairs of electrodes, for sensing the magnitude of the tunneling current flow and for adjusting the potentials applied between an appropriate pair or pairs of said electrodes so as to move said tip in a manner to adjust said tunneling current to a desired level.