Laser beam applying mechanism and laser processing apparatus

Abstract

A laser beam applying mechanism has a power adjusting unit provided between a laser beam oscillator and a focusing lens. The power adjusting unit includes a half-wave plate, a prism having a first polarization beam splitter film and a second polarization beam splitter film. The optical path is adjusted by a piezoelectric actuator opposed to the first polarization beam splitter film, and a polarized light components synthesizer opposed to the second polarization beam splitter film generates a phase difference ([beta]) between an S polarized light component and a P polarized light component. The phase difference ([alpha+beta]) between the S polarized light component and the P polarized light component of the laser beam obtained by the polarized light components synthesizer is in the range of 0 DEG to 180 DEG .

Description

technical field [0001] The present invention relates to a laser beam irradiation mechanism and a laser processing device capable of high-speed control of the output of laser beam oscillated from a laser beam oscillator. Background technique [0002] In the manufacturing process of semiconductor devices, a plurality of regions are divided on the surface of a roughly disc-shaped semiconductor wafer by dividing lines called dicing lines arranged in a grid pattern, and devices such as ICs and LSIs are formed in the divided regions. . Then, the semiconductor wafer is cut along the dicing lines to divide the regions where the devices are formed to manufacture individual semiconductor devices. [0003] Severing of semiconductor wafers along dicing streets is usually performed by a cutting device called a dicing saw. This cutting device has: a chuck table, which holds a semiconductor wafer as a workpiece; a cutting unit, which cuts the semiconductor wafer held by the chuck table; ...

AI Technical Summary

Problems solved by technology

Also, the Low-k film has the problem that since it is laminated in multiple layers (5 to 15 layers) like mica and is very brittle, when the Low-k film is cut along the dicing line by a cutting knife, the Low-k film is peeled off, and the peeled-off reaches the circuit. Semiconductor chips bring fatal damage

[0006] However, in a semiconductor wafer in which a test metal pattern called a test element group (TEG) for testing circuit functions is partially arranged on the Low-k film on the dicing line, there is a problem that even if the Low-k film is irradiated with laser light to remove the The metal pattern made of copper or aluminum hinders the laser light and cannot remove the Low-k film smoothly

In addition, when the output of the laser beam is increased to the extent that the metal pattern can be removed and the laser beam is irradiated to the scribe line, the following new problem also occurs: the semiconductor substrate only in the scribe line portion where the Low-k film is formed is broken and fragmented. Flying, the debris adheres to the bonding pads connected to the circuit, etc., deteriorating the quality of the semiconductor chip

[0010] However, it is difficult to adjust the output of the laser beam oscillated from the laser beam oscillator in accordance with the processing feed rate, and it is also difficult to reliably remove the area where the metal pattern for testing is located.

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