Laser processing apparatus

Abstract

A laser processing apparatus includes a chuck table for holding a workpiece and a laser beam applying unit for applying a laser beam to the workpiece. A laser beam oscillating unit oscillates a laser beam and a focusing unit focuses the laser beam onto the workpiece. A reflecting unit is provided on the optical axis of the focusing unit. A wavelength detecting unit detects the wavelength of the plasma light reflected by the reflecting unit, and a controller determines the material of the workpiece according to a detection signal from the wavelength detecting unit, to control the laser beam applying unit.

Description

technical field [0001] The present invention relates to a laser processing device for forming a laser processing hole in a workpiece such as a semiconductor wafer. 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 streets arranged in a grid, and ICs, LSI and other devices. Then, the semiconductor wafer is cut along the lanes, whereby the regions where the devices are formed are divided to manufacture individual semiconductor chips. [0003] In order to achieve miniaturization and high functionality of devices, a module structure in which a plurality of devices are stacked and bonding pads provided on the stacked devices are connected has been put into practical use. The structure of this module structure is to form a through hole (through hole) in the position where the bonding pad is provided on the semiconductor wafer,...

AI Technical Summary

Problems solved by technology

[0011] However, since the bonding pad made of metal is located at the bottom of the fine hole formed by irradiation of laser light, there is a problem that even if plasma is generated by irradiation of laser light, it is difficult to reliably determine the inherent nature of the substance emitted by the plasma. spectrum

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