I-Corps: Spot Beam Annealing for Laser Crystallization and Liftoff

This I-Corps project is based on the development of a technique for large area laser processing called spot beam annealing. This technology represents a fabrication method in which a focused laser beam melts or vaporizes material in a localized area, creating intricate cuts, patterns, or designs. Laser techniques offer a number of advantages for the processing of thin film semiconductors. The spot beam annealing technology may be used in thermal laser annealing applications and employs advanced lasers and optics to spread the light from a high-power laser system, allowing the treatment of a large area. Currently, there is a need to reduce the cost and complexity of the beam forming optics. The technology has been shown to simplify the optics that are used for beam spreading and control. In addition, the technology may reduce costs and permit the development of new laser processing approaches that may improve the performance of a range of electronic systems including displays, memories, and microcontroller devices. This I-Corps project utilizes experiential learning coupled with a first-hand investigation of the industry ecosystem to assess the translation potential of spot beam annealing and related techniques for large area laser processing. Spot beam annealing is an advanced laser crystallization and heat treatment technology that can be used in low-temperature polycrystalline silicon (LTPS) and low-temperature polycrystalline oxide (LTPO) processes for producing large-area display panels. This solution may be used for large area organic light-emitting diode (OLED) displays, x-ray imagers, touch sensors, or backplanes for micro-light emitting diodes (LEDs). In addition, spot beam annealing may allow for the use of lower cost optical elements than traditional line beam shaping techniques while delivering potentially superior electrical performance for annealing. Spot beam techniques also may be useful for other laser processing such as spike annealing and laser liftoff. Spot beam annealing rapidly scans a high-power pulsed laser spot forming a continuous melt in the amorphous silicon layer. This technique provides highly efficient laser power usage and the ability to shape the spot beam in a predetermined geometrical dimension, intensity profile, and temporal profile. These additional parameters allow for more control of the process to create an improved uniformity of crystallization, and transistor performance. This solution may offer reduced cost and better performance in applications including laser crystallization, laser liftoff of polymer and inorganic substrates, and other techniques used for laser thermal annealing. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.