Method of Fabrication of Display Pixels Driven by Silicon Thin Film Transistors

Method of Fabrication of Display Pixels Driven by Silicon Thin Film Transistors
Author:
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Total Pages:
Release: 1999
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Display pixels driven by silicon thin film transistors are fabricated on plastic substrates for use in active matrix displays, such as flat panel displays. The process for forming the pixels involves a prior method for forming individual silicon thin film transistors on low-temperature plastic substrates. Low-temperature substrates are generally considered as being incapable of withstanding sustained processing temperatures greater than about 200.degree. C. The pixel formation process results in a complete pixel and active matrix pixel array. A pixel (or picture element) in an active matrix display consists of a silicon thin film transistor (TFT) and a large electrode, which may control a liquid crystal light valve, an emissive material (such as a light emitting diode or LED), or some other light emitting or attenuating material. The pixels can be connected in arrays wherein rows of pixels contain common gate electrodes and columns of pixels contain common drain electrodes. The source electrode of each pixel TFT is connected to its pixel electrode, and is electrically isolated from every other circuit element in the pixel array.

Integrated Thin-Film Transistor Display

Integrated Thin-Film Transistor Display
Author: W. J. Helm
Publisher:
Total Pages: 42
Release: 1978
Genre:
ISBN:

This report summarizes the work performed on a program whose purpose is to develop techniques for producing flat-panel electroluminescent displays with integrated thin-film transistor circuitry. Included are descriptions of the overall design and configuration of the display device; the design and structure of the electroluminescent elements, thin-film transistors, driver circuits, and addressing circuits of the display device; the processes and equipment being used to fabricate these devices; and the process development and improvement efforts being conducted.

Enabling Technology for Thin Film Displays

Enabling Technology for Thin Film Displays
Author:
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Total Pages: 154
Release: 2002
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This program has laid the foundations for rugged, flexible, bendable high performance thin-film transistor (TFT) backplanes for display and sensor/detector array applications and has further developed patterned organic layers for color OLED's using both wet and dry processes. Innovations have been made in transistor materials and processing, substrate treatments and processing, and systems integration. Six backplane TFT technologies have been developed for flexible substrates: (1) amorphous silicon TFTs on steel foils, which yields TFT structures which are rugged and dimensionally stable; (2) polycrystalline silicon TFT complementary metal oxide on silicon (CMOS) on steel foils, which takes advantage of the high temperature tolerance of steel; (3) high performance polycrystalline silicon (p-Si) TFT CMOS using a separation approach which allows full high-temperature processing and yields mobilities for holes and electrons over 300 square centimeters/volt-second; (4) amorphous silicon (a-Si) TFTs on plastic (Kapton) foil using an amorphous silicon process optimized for 150 deg C, (5) nanocrystalline silicon (n-Si) TFTs using processing that is adaptable to direct deposition on plastic foil substrates, and (6) polymeric TFTs fully compatible with flexible substrates and demonstrating record mobilities. In the OLED work, both wet and dry patterning for OLED processing have been found to be compatible with roll-roll processing and not to require vacuum. Wet processes (e.g., ink jet printing) have been found to depend critically on the final printed profiles which result from the drying process of the liquid. By developing a solvent-assisted diffusion process for organic molecules in polymers, which can temporarily depress glass transition temperatures by over 100 deg C, a practical large-area dry-patterning process has been developed for patterning color OLED's.

Process for Direct Integration of a Thin-film Silicon P-n Junction Diode with a Magnetic Tunnel Junction

Process for Direct Integration of a Thin-film Silicon P-n Junction Diode with a Magnetic Tunnel Junction
Author:
Publisher:
Total Pages:
Release: 2003
Genre:
ISBN:

A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

Introduction to Thin Film Transistors

Introduction to Thin Film Transistors
Author: S.D. Brotherton
Publisher: Springer Science & Business Media
Total Pages: 467
Release: 2013-04-16
Genre: Technology & Engineering
ISBN: 3319000020

Introduction to Thin Film Transistors reviews the operation, application and technology of the main classes of thin film transistor (TFT) of current interest for large area electronics. The TFT materials covered include hydrogenated amorphous silicon (a-Si:H), poly-crystalline silicon (poly-Si), transparent amorphous oxide semiconductors (AOS), and organic semiconductors. The large scale manufacturing of a-Si:H TFTs forms the basis of the active matrix flat panel display industry. Poly-Si TFTs facilitate the integration of electronic circuits into portable active matrix liquid crystal displays, and are increasingly used in active matrix organic light emitting diode (AMOLED) displays for smart phones. The recently developed AOS TFTs are seen as an alternative option to poly-Si and a-Si:H for AMOLED TV and large AMLCD TV applications, respectively. The organic TFTs are regarded as a cost effective route into flexible electronics. As well as treating the highly divergent preparation and properties of these materials, the physics of the devices fabricated from them is also covered, with emphasis on performance features such as carrier mobility limitations, leakage currents and instability mechanisms. The thin film transistors implemented with these materials are the conventional, insulated gate field effect transistors, and a further chapter describes a new thin film transistor structure: the source gated transistor, SGT. The driving force behind much of the development of TFTs has been their application to AMLCDs, and there is a chapter dealing with the operation of these displays, as well as of AMOLED and electrophoretic displays. A discussion of TFT and pixel layout issues is also included. For students and new-comers to the field, introductory chapters deal with basic semiconductor surface physics, and with classical MOSFET operation. These topics are handled analytically, so that the underlying device physics is clearly revealed. These treatments are then used as a reference point, from which the impact of additional band-gap states on TFT behaviour can be readily appreciated. This reference book, covering all the major TFT technologies, will be of interest to a wide range of scientists and engineers in the large area electronics industry. It will also be a broad introduction for research students and other scientists entering the field, as well as providing an accessible and comprehensive overview for undergraduate and postgraduate teaching programmes.