"Lead Inventor:
James S. Im, Ph.D.
Super Lateral Growth (SLS) Techniques can Cause Microstructure Defects in Electrical Components and Circuits
Super lateral growth (SLG) is a process whereby a polycrystalline semiconductor film is produced by annealing an amorphous film prepared with vacuum deposition. Sequential Lateral Solidification (SLS) is a method for applying repeated SLG steps to a film to achieve greater control of the resulting polycrystalline microstructure. Although current SLS techniques can produce directional microstructure and hence higher charge carrier mobility in the resulting films, these techniques also cause microstructure nonuniformities, such as subgrains with different orientations, to arise in different regions of the film. These nonuniformity defects can limit the performance of electrical components and circuits fabricated with such films.
SLS Technolgy Lithographically Patterns Semiconductor Film to Meet High Device Uniformity Requirements
The technology is a novel SLS method that lithographically patterns the semiconductor film being annealed into regions whose size and shape prevent the formation of microstructure nonuniformities. Localized irradiation of sufficiently narrow regions of film can limit the number of metagrains that form during annealing; this reduces the number of intergrain boundaries in the resulting polycrystalline film.
Applications:
-- The technology can be used to fabricate electrical elements such as active matrix organic light emitting diodes (AMOLEDs) that have high device uniformity requirements.
-- The technology can be used to produce inexpensive polycrystalline silicon photovoltaic cells.
-- The technology can facilitate the fabrication of nonplanar integrated circuits that would otherwise be adversely affected by film nonuniformity defects.
Advantages:
-- The use of lithographic techniques to protect regions of a film from irradiation enables the use of less costly light sources such as flash lamps in SLS processing.
-- The technology can reduce the cost of photovoltaic cell fabrication.
-- Improving thin film microstructure uniformity with the technology can increase the performance of thin film transistor liquid crystal displays (TFT-LCDs).
Patent Information:
Patent Issued
Licensing Status: Available for Sponsored Research Support
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Patent No. 8,614,471