Christos D Dimitrakopoulos

US Patent:

6335539, Jan 1, 2002

Filed:

Nov 5, 1999

Appl. No.:

09/434365

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY
Ioannis Kymissis - New Hyde Park NY
Sampath Purushothaman - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 3524

US Classification:

257 40, 438 99

Abstract:

A method for improving the performance of an organic thin film field effect transistor comprising the steps of: (a) forming a transistor structure having patterned source and drain electrodes; and (b) treating the patterned source and drain electrodes with a thiol compound having the formula, RSH, wherein R is a linear or branched, substituted or unsubstituted, alkyl, alkenyl, cycloalkyl or aromatic containing from about 6 to about 25 carbon atoms under conditions that are effective in forming a self-assembled monolayer of said thiol compound on said electrodes. Organic thin film transistor structures containing the self-assembled monolayer of the present invention are also disclosed.

US Patent:

6344660, Feb 5, 2002

Filed:

Jun 2, 1999

Appl. No.:

09/323804

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY
Peter Richard Duncombe - Peekskill NY
Bruce K. Furman - Beacon NY
Robert B. Laibowitz - Peekskill NY
Deborah Ann Neumayer - Danbury CT
Sampath Purushothaman - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 3524

US Classification:

257 40, 257289, 257295, 257310

Abstract:

A thin film transistor (TFT) device structure based on an organic semiconductor material, that exhibits a high field effect mobility, high current modulation and a low sub-threshold slope at lower operating voltages than the current state of the art organic TFT devices. The structure comprises a suitable substrate disposed with he following sequence of features: a set of conducting gate electrodes covered with a high dielectric constant insulator, a layer of the organic semiconductor, sets of electrically conducting source and drain electrodes corresponding to each of the gate lines, and an optional passivation layer that can overcoat and protect the device structure. Use of high dielectric constant gate insulators exploits the unexpected gate voltage dependence of the organic semiconductor to achieve high field effect mobility levels at very low operating voltages. Judicious combinations of the choice of this insulator material and the means to integrate it into the TFT structure are taught that would enable easy fabrication on glass or plastic substrates and the use of such devices in flat panel display applications.

US Patent:

6344662, Feb 5, 2002

Filed:

Nov 1, 2000

Appl. No.:

09/703964

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY
Cherie Renee Kagan - Ossining NY
David Brian Mitzi - Mahopac NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 3524

US Classification:

257 40, 257289, 257310

Abstract:

A thin film transistor (TFT) device structure based on an organic-inorganic hybrid semiconductor material, that exhibits a high field effect mobility, high current modulation at lower operating voltages than the current state of the art organic-inorganic hybrid TFT devices. The structure comprises a suitable substrate disposed with the following sequence of features: a set of conducting gate electrodes covered with a high dielectric constant insulator, a layer of the organic-inorganic hybrid semiconductor, sets of electrically conducting source and drain electrodes corresponding to each of the gate lines, and an optional passivation layer that can overcoat and protect the device structure. Use of high dielectric constant gate insulators exploits the gate voltage dependence of the organic-inorganic hybrid semiconductor to achieve high field effect mobility levels at very low operating voltages. Judicious combinations of the choice of this high dielectric constant gate insulator material and the means to integrate it into the organic-inorganic hybrid based TFT structure are taught that would enable easy fabrication on glass or plastic substrates and the use of such devices in flat panel display applications.

US Patent:

6437422, Aug 20, 2002

Filed:

May 9, 2001

Appl. No.:

09/852078

Inventors:

Paul M. Solomon - Yorktown Heights NY
Jane Margaret Shaw - Branford CT
Cherie R. Kagan - Ossining NY
Christos Dimitrios Dimitrakopoulos - West Harrison NY
Tak Hung Ning - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 2906

US Classification:

257618, 257 40

Abstract:

Active devices that have either a thread or a ribbon geometry. The thread geometry includes single thread active devices and multiple thread devices. Single thread devices have a central core that may contain different materials depending upon whether the active device is responsive to electrical, light, mechanical, heat, or chemical energy. Single thread active devices include FETs, electro-optical devices, stress transducers, and the like. The active devices include a semiconductor body that for the single thread devices is a layer about the core of the thread. For the multiple thread devices, the semiconductor body is either a layer on one or more of the threads or an elongated body disposed between two of the threads. For example, a FET is formed of three threads, one of which carries a gate insulator layer and a semiconductor layer and the other two of which are electrically conductive and serve as the source and drain. The substrates or threads are preferably flexible and can be formed in a fabric.

US Patent:

6500604, Dec 31, 2002

Filed:

Jan 3, 2000

Appl. No.:

09/476275

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY
Ioannis Kymissis - New Hyde Park NY
Sampath Purushothaman - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G03C 558

US Classification:

430322, 430323, 430961, 438455, 438629

Abstract:

A method for patterning a chemically sensitive organic thin film such as pentacene comprising (a) forming a protective material layer on the surface of a chemically sensitive organic thin film, said protective material layer being chemically resistant; (b) forming a photoresist on an exposed surface of said protective material layer; (c) patterning the photoresist; and (d) transferring the pattern to the protective material layer and the chemically sensitive organic thin film by dry etching.

US Patent:

6569707, May 27, 2003

Filed:

Oct 29, 2001

Appl. No.:

10/020698

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY
Ioannis Kymissis - New Hyde Park NY
Sampath Purushothaman - Yorktown Heights NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 5140

US Classification:

438 99, 438 57, 438 82, 438 96, 438 97, 257 40

Abstract:

A method for improving the performance of an organic thin film field effect transistor including the steps of: (a) forming a transistor structure having patterned source and drain electrodes; and (b) treating the patterned source and drain electrodes with a thiol compound having the formula, RSH, wherein R is a linear or branched, substituted or unsubstituted, alkyl, alkenyl, cycloalkyl or aromatic containing from about 6 to about 25 carbon atoms under conditions that are effective in forming a self-assembled monolayer of said thiol compound on said electrodes. Organic thin film transistor structures containing the self-assembled monolayer of the present invention are also disclosed.

US Patent:

6963080, Nov 8, 2005

Filed:

Nov 20, 2002

Appl. No.:

10/300630

Inventors:

Tricia L Breen - Hopewell Junction NY, US
Christos D Dimitrakopoulos - Ossining NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L051/30

US Classification:

257 40, 257 66, 257E51006

Abstract:

The present invention describes thin film transistors in which the active channel layer is a thin film of a polycyclic aromatic compound, such as, pentacene, prepared by solution processing a soluble precursor of the polycyclic aromatic compound on a substrate followed by heating to a moderate temperature to convert the precursor back to the polycyclic aromatic compound. The soluble precursors of the polycyclic aromatic compounds are organic solvent-soluble Diels-Alder adducts of polycyclic aromatic compounds, such as, oligothiophene, perylene, benzo[ghi]perylene, coronene and a polyacene with a variety of dienophiles that contain at least one heteroatom. The Diels-Alder adducts can be converted back to pentacene by retro-Diels-Alder reaction at moderate (60-250 C. ) temperatures both in bulk, in solution or as thin-films.

US Patent:

7026643, Apr 11, 2006

Filed:

Dec 11, 2001

Appl. No.:

10/014766

Inventors:

Christos Dimitrios Dimitrakopoulos - West Harrison NY, US
Jeffrey Donald Gelorme - Plainville CT, US
Teresita Ordonez Graham - Irvington NY, US
Laura Louise Kosbar - Mohegan Lake NY, US
Patrick Roland Lucien Malenfant - Clifton Park NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01L 29/772

US Classification:

257 40, 257288, 257 72

Abstract:

The invention provides a device comprising an improved n-channel semiconducting film. This film consists of a perylene tetracaboxylic acid diimide compound and was deposited onto substrates by vacuum sublimation. Thin film transistor devices comprising such films as the semiconducting channel exhibit a field effect electron mobility greater than 0. 01 cm/Vs and an on/off ratio of 10000 and higher.