Laser-based method and system for processing targeted surface material and article produced thereby

Abstract

A laser-based method and system for processing targeted surface material and article produced thereby are provided. The system processes the targeted surface material within a region of a workpiece while avoiding undesirable changes to adjacent non-targeted material. The system includes a primary laser subsystem including a primary laser source for generating a pulsed laser output including at least one pulse having a wavelength and a pulse width less than 1 ns. A delivery subsystem irradiates the targeted surface material of the workpiece with the pulsed laser output including the at least one pulse to texture the targeted surface material. The pulsed laser output has sufficient total fluence to initiate ablation within at least a portion of the targeted surface material and the pulse width is short enough such that the region and the non-targeted material surrounding the material are substantially free of slag.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. provisional application Ser. No. 60 / 584,268, filed Jun. 30, 2004.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to laser marking and texturing, particularly forming at least semi-permanent or erasable indicia on one or more materials of a microelectronic device. The materials may include semiconductor substrates, thin films, metallization, and dielectric layers. One or more embodiments may also be applied for forming indicia on MEMs, optoelectronic devices, or biomedical microchips. Various embodiments are useable for various micromachining or microfabrication applications. [0004] 2. Background Art [0005] Prior to 1999, Silicon wafer marking was used for identification at wafer level. Initially driven by the Known Good Die, and more recently by traceability and component identification, laser marking on the backside of the wafer at the die leve...

AI Technical Summary

Benefits of technology

The present invention provides a method for creating indicia on a microelectronic article by using a pulsed laser to texture the surface material of the article. The method involves applying a pulsed laser output to a localized region of the material with sufficient total fluence to initiate ablation within the region. The laser output has a short pulse width, which allows for precise control of the ablation process without causing damage to adjacent non-targeted material. The method can be used to create indicia that are at least semi-permanent or erasable, and can be used in the manufacturing of microelectronic devices. The method can also include using a secondary laser output to process the textured surface material. The textured surface material can include nanotextured or microtextured surface material, and the indicia can be formed using a femtosecond or picosecond laser. The invention provides a way to create high-quality indicia on microelectronic articles without causing damage or affecting the surrounding non-targeted material.

Problems solved by technology

One of the emerging challenges for die marking is the recent introduction of very thin wafers.

Another challenge is the continuing shrinking of die sizes.

Traditional wafer marking systems are not well suited to present and emerging requirements.

Images