1. Field of the Invention
This invention generally relates to the fabrication of integrated circuit (IC) devices and, more particularly, to the assembly of thin sheets of single crystal silicon onto substrates.
2. Description of the Related Art
The use of substrate materials other than silicon is of interest, as it would enable the realization of new display products that are not otherwise feasible to make. For example, there is broad agreement in the flat panel display (FPD) industry that system-on-glass (SOG) technology is a natural evolutionary step for FPDs, especially for mobile devices. As an example of this evolution, improvements in liquid crystal display (LCD) technology create a need for high performance thin film transistor (TFT) driver components on transparent substrates such as glass and polymer. In fact, SOG is a natural confluence of display and microprocessor evolution, because integration is a proven solution for greatly reducing costs while improving the compactness and reliability of electrical systems.
Another aspect of interest is flexibility, the ability of a microsystem to bend, conform, or maintain its integrity under external “stress”. These attributes would enable the manufacturing of a variety of one-use products and/or the manufacturing of robust products that maintain their functionality under a wide range of external, “environmental” conditions. Therefore, there is motivation to develop Microsystems or products that use TFT microelectronic devices that are robust, have high performance, and are cheap to make.
Low-temperature polysilicon (LTPS) technology uses a laser beam to crystallize amorphous silicon and form thin polycrystalline silicon layers, also referred to as polysilicon layers. Display drivers and analog-to-digital converters for SOG devices can be formed in this manner. Unfortunately, this approach remains relatively expensive for LCD production. Moreover, polysilicon TFTs formed by LTPS technology may not provide the capability to realize sophisticated functions like central processor unit (CPU) operations and digital signal processing. Finally, the steadiness of drive currents produced by polysilicon TFTs may be inadequate for organic light emitting diode displays (OLEDs).
It would be advantageous if a process could inexpensively use SOG technology to produce TFTs able to implement sophisticated functions like CPU and digital signal processing.
It would be advantageous if a process could inexpensively use SOG technology to produce TFTs with drive currents sufficient for OLEDs.
It would be advantageous if a process could inexpensively produce TFT microelectronic devices on flexible substrates.
USPTO Backgrounds
USPTO Backgrounds