Semiconductor device manufacturing: process – Having organic semiconductive component
Reexamination Certificate
1999-03-09
2001-03-27
Niebling, John F. (Department: 2812)
Semiconductor device manufacturing: process
Having organic semiconductive component
C438S149000, C438S158000, C438S216000, C438S240000, C438S287000, C438S785000
Reexamination Certificate
active
06207472
ABSTRACT:
Cross Reference is made to U.S. Pat. Nos. 5,996,551 and 5,981,570; assigned to the assignee of this application; arising out of a continuing technological effort and incorporated herein by reference.
FIELD OF THE INVENTION
This invention pertains to thin film field effect transistors (TFT), and in particular to the structure and processing of such TFT devices at a low, of the order of 150 degrees C., or less temperature.
BACKGROUND AND RELATION TO THE PRIOR ART
Thin film field effect transistors (TFT), useful in flat panel display applications, at the current state of the art, involve a semiconductor layer with a channel defined by separated source and drain electrodes on one side and an insulated gate electrode on the other side that is centered with respect to the channel. The structure of the TFT device is usually fabricated through a set of serial deposition operations of carefully controlled layers on a substrate. The desired TFT electrical performance involves low voltage operation with high carrier mobility in the channel, and with current vs voltage output characteristics that include a steep slope followed by a saturation region.
The current TFT devices typically use amorphous silicon (a—Si:H) as the semiconductor and silicon oxide and/or silicon nitride as the gate insulator. Some attention in the art is being directed toward the use of semiconducting organic compounds as potential replacements for amorphous silicon as the semiconductor.
As the art is progressing, in addition to the ever increasing stringency of requirements for increases in density and responsiveness of the components, it is also becoming desirable that transparent substrates have mechanical flexibility, impact resistance and light weight. Meeting all the constraints is becoming more difficult to achieve. Many materials and processing techniques used in the fabrication of active matrix liquid crystal displays (AMLCD), that are based on a—Si: H TFT devices involve temperatures above 350 degrees C. which operates to eliminate many otherwise useful substrate materials. A need is growing in the art for a broader range of materials and processes for TFT devices, particularly under the rigorous criteria in the display type of application. Transparent plastic substrates for AMLCD are very desirable but cannot withstand temperatures above 150-200 degrees C.
SUMMARY OF THE INVENTION
The invention broadens the range of materials and processes available for TFT devices by providing in the device suture an organic semiconductor layer that is in contact with an inorganic mixed oxide gate insulator involving processing with the types of processing techniques that can take place in a temperature range from about room temperature to about 150 degrees C.
A TFT of the invention has a pentacene semiconductor layer in contact with a barium zirconate titanate gate insulator layer formed on a polycarbonate transparent substrate employing at least one of the techniques of sputtering, spinning, evaporation and laser ablation.
REFERENCES:
patent: 5347144 (1994-09-01), Garnier et al.
patent: 5946551 (1999-08-01), Dimitrakopoulos et al.
patent: 5981970 (1999-11-01), Dimitrakopoulos et al.
Horowitz et al, “A Field Effect Transistor Based on Conjugated Alpha-Sexithienyl,” Solid State Communications, vol. 72, No. 4, pp. 381-384, 1989.
Lin et al, “High Mobility Pentacene Organic Thin Film Transistors” IEEE 54thAnnual Device Research Conf. Digest, 1996, pp. 80-81.
Chen et al, “High Field Effect Mobility a-Si:H TFT Based on High Deposition Rate Materials” IEEE 54thAnnual Device Research Conf. Digest, 1996, pp. 68-69.
Wu et al. “Highly Insulative Barium-Zirconite-Titanate Thin Films Prepared by RF Magnetron Sputtering for Dynamic Random Access Memory Applications” Applied Physics Letters 69(18) Oct. 28, 1996 pp. 2659-2661.
Dimitrakopoulos et al, “Molecular Beam Deposited Thin Films of Pentacene for Organic Field Transistor Applications,” J. App. Phys., 80,(4) Aug. 15, 1996 pp. 2501-2508.
P. Balk, “Dilectrics for Field Effect Technology”, Advanced Materials, vol. 7 No. 8, 1995 pp. 703-710.
Brown et al, “Precursor Route Pentacene Metal-Insulator-Semiconductor Field Effect Transistors”, J. App. Phys. 79(4) Feb. 15, 1996, pp. 2136-2138.
Garnier et al, “All Polymer Field Effect Transistor Realized by Printing Techniques”, Science, vol. 265, Sep. 16, 1994, pp. 1684-1686.
Bao et al, “High-Performance Plastic Transistors Fabricated by Printing Techniques”, Chem. Mater., vol. 9, 1997, pp. 1299-1301.
“All-Polymer Integrated Circuits”, Semiconductor International, Apr. 1998, p. 42.
Dimitrakopoulos et al, “Low Voltage Organic Transistors on Plastic Comprising High-Dielectric Constant Gate Insulators”, Science, vol. 283, Feb. 5, 1999, pp. 822 to 824 and 771 and 772.
Callegari Alessandro Cesare
Dimitrakopoulos Christos Dimitrios
Purushothaman Sampath
Hack Jonathan
International Business Machines - Corporation
Morris Daniel P.
Niebling John F.
Riddles Alvin J.
LandOfFree
Low temperature thin film transistor fabrication does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Low temperature thin film transistor fabrication, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low temperature thin film transistor fabrication will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2524013