Devices having a semiconductor/conducting polymer interface

• US 6,455,873 B1
• Filed: 12/01/1998
• Issued: 09/24/2002
• Est. Priority Date: 12/03/1997
• Status: Expired due to Fees

• Current Assignee: University of Oregon
• Original Assignee: University of Oregon
• Inventors: Lonergan, Mark C.
• Primary Examiner(s): Williams, Alexander O.
• Application Number:
  US09/204,621
• Time in Patent Office: 1,393 Days
• Field of Search: 257/787, 257/40, 257/431, 257/436, 257/448, 257/464, 257/184, 257/440, 257/461, 257/99, 257/88, 257/91, 257/103
• US Class Current: 257/40
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 27/129 Diode type sensors, e.g. gas sensitive Schottky diodes capacitor type sensors G01N27/227; field-effect transistor type sensors G01N27/414

Abstract

Microelectronic devices have a semiconductor/conducting polymer interface are disclosed. The conducting polymer may be electrically contacted in a manner to assure that it remains exposed to the environment. If the environment is an inert electrolyte to which additional electrodes are contacted, the conducting polymer can be electrochemically oxidized or reduced to control its electrochemical potential and a tunable (variable barrier) diode results. This tunable diode is a device that rectifies current like a traditional diode, but unlike traditional diodes, the effective barrier height of the tunable diode can be actively controlled. This control can be an element of an active device or a means for fabricating fixed barrier diodes with controlled barrier heights. Alternatively, the environment can contain an analyte to be sensed, either directly or through a mediating layer. The electrical characteristics (e.g. current-voltage or capacitance voltage) of the semiconductor/conducting polymer interface can be used to sense the analyte if it induces a change in the electrochemical potential of the conducting polymer.

Claims

1. A microelectronic device comprising:

a body of conducting polymer;

an electrical contact to the body of conducting polymer;

a body of semiconductor material in electrical contact with the body of conducting polymer; and

an electrical contact to the body of semiconductor material, the device being configured such that at least a portion of the body of conducting polymer is exposed to the environment.

2. The device of claim 1 wherein:

at least a portion of the body of conducting polymer is exposed to an environment that is an electrolyte; and

the device further comprises at least one electrode that is in contact with the electrolyte at a distance away from the body of conducting polymer.

3. The device of claim 1 further comprising:

an insulating substrate, the body of semiconductor material being supported on the substrate; and

a electrically conductive contact supported on the substrate at a distance from the body of semiconductor material, the body of conducting polymer being positioned in physical contact with both the body of semiconductor material and the electrically conductive contact such that an electrical connection exists between the body of semiconductor material and the electrically conductive contact via the conducting polymer.

4. The device of claim 1 further comprising:

an insulating substrate, the body of semiconductor material being supported on the substrate and the body of conducting polymer being superposed on and in physical contact with the body of semiconductor material; and

a grid electrode superposed on and in physical contact with the body of conducting polymer, the grid being sufficiently porous that at least a portion of the body of conducting polymer is exposed to the environment via openings through the grid electrode.

5. The device of claim 1 further comprising:

an insulating substrate, the body of semiconductor material being supported on the substrate and the body of conducting polymer being superposed on and in physical contact with the body of semiconductor material; and

a porous electrically conductive contact superposed on and in physical contact with the body of conducting polymer, the electrically conductive contact being sufficiently porous that at least a portion of the body of conducting polymer is exposed to the environment via openings through the porous electrically conductive contact.

6. The device of claim 1 wherein the body of semiconductor material is at least partially encapsulated so that the body of semiconductor material is not exposed to the environment.

7. A diode comprising:

an electrolyte;

a body of conducting polymer, at least a portion of the body of conducting polymer being in contact with the electrolyte;

a body of semiconductor material in electrical contact with the body of conducting polymer material; and

at least one electrode that is in contact with the electrolyte at a distance away from the body of conducting polymer.

8. The diode of claim 7 further comprising a control device electrically connected to the body of conducting polymer and to the electrode to control the electrochemical potential of the polymer.

9. The diode of claim 8 wherein:

the electrode comprises at least two separate electrodes that are in contact with the electrolyte at a distance away from the body of conducting polymer; and

the control device is a potentiostat.

10. The diode of claim 7 wherein:

the electrode is a single combination electrode that serves as both a reference electrode and a counter electrode.

11. The diode of claim 10 wherein:

the electrolyte is contained in a chamber defined by a wall; and

the combination electrode serves as at least a portion of the wall the that defines the chamber.