Flat panel displays are used in many applications to visually present data and images. Flat panel displays have a thin profile and provide high resolution for uses such as computer monitors and television screens. The liquid crystal display (LCD) is one type of flat panel display. The LCD uses a silicon on glass substrate. The active semiconductor-based pixels are formed on the silicon substrate. The glass substrate is conducive to high temperatures which are commonly used in many semiconductor manufacturing processes.
While LCDs have been around for some time and are generally preferred over CRT-type displays, such glass-based flat panel displays have disadvantages as well. The glass component is known to be heavy and brittle. LCDs are known to crack and are susceptible to damage. Moreover, glass displays are generally not useable in applications requiring flexibility for the display.
As new applications arise, the need for flexible flat panel displays continues to grow. Prior art flexible flat panel displays use thin film transistors (TFT) formed on amorphous silicon layers or polycrystalline silicon layers. Unfortunately, amorphous silicon and polycrystalline silicon TFTs exhibit low carrier mobility and high off-state current leakage, which reduces performance and increases power consumption. The resolution decreases and flickering may be observed in flat panel displays using TFTs formed on low carrier mobility polycrystalline silicon.
A similar problem is found in electronic devices using polycrystalline silicon. The-lower carrier mobility associated with polycrystalline type substrates reduces the performance of the electronic device.
On the other hand, single crystalline silicon is known to have greater carrier mobility. The higher carrier mobility in the presence of an electrostatic field, as found in single crystalline silicon, provides better performance for flat panel displays and electronic devices. However, single crystalline silicon typically involves higher temperature semiconductor processes. These high temperatures are incompatible with polymer and other flexible amorphous substrates.
A need exists for a flat panel display or electronic device using single crystalline silicon on a flexible substrate.
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