System and method for deliverying laser beam and laser lift-off method using the same

Abstract

The present invention provides a system and method for delivering laser beam, and a laser lift-off (LLO) method, one of the inevitable processes for fabricating a vertical type LED. A laser beam delivery system of the present invention comprises a laser beam source for emitting laser beam; a beam homogenizer for improving uniformity of energy intensity of the laser beam, the beam homogenizer comprising a microlens type fly-eye lens; a mask for masking a peripheral area of a cross section of the laser beam having penetrated the beam homogenizer at a focal plane; and an imaging lens for applying the laser beam to a unit irradiation area of a target. According to the present invention, the uniformity of energy intensity all over the beam spot is improved and thus the process yield is also remarkably increased. Besides, the beam transmittance is improved and thus the production per unit time is also raised. Further, the manufacturing process is simplified, the manufacturing cost is reduced, and thus the competitive power in LED market is improved.

Description

technical field [0001] The present invention relates to a laser beam delivery system and method, in particular to a system and method for delivering a laser beam to separate a thin film from a substrate, and more particularly, to a laser lift-off (LLO) ) process laser beam delivery system and method, the LLO process is one of the necessary processes for manufacturing vertical LED (Light Emitting Diode, light emitting diode). Background technique [0002] In general, excimer lasers have multiple uses in material processing, for example, to precisely process and separate two different materials bonded to each other. More recently, as the stability and intensity of excimer laser beams have improved, their use has expanded to include the processing of semiconductor materials, especially the separation of thin films from silicon substrates used to fabricate devices. A wide variety of thin films are separated, including: compound semiconductors, copper, aluminum, gold, polymers, ...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the size of the whole system, there will still be a limitation of the uniformity of the energy intensity

In addition, since the beam expander telescope is additionally used, the complexity of manufacturing the entire laser beam delivery system increases, and also increases the manufacturing cost

In addition, the beam transmission of the system is reduced because the laser beam must pass through an additional optics beam expander telescope

[0025] Furthermore, since the laser beam cannot penetrate the cylindrical fly-eye lens at the contact surface between the cylindrical small lens and the cylindrical fly-eye lens, wherein the cylindrical fly-eye lens includes two layers of optical elements for the laser beam to penetrate, the cylindrical fly-eye lens Lenses 110 and 120 have fundamental problems with beam transmission

Therefore, LED production per unit of time is significantly limited due to the low beam transmission, which indicates how much of the initial beam penetrates the entire system and reaches the wafer.

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