Wafer processing apparatus

Patent metadata

Field	Value
Publication number	US-2017323774-A1
Application number	US-201715584228-A
Country	US
Kind code	A1
Filing date	May 2, 2017
Priority date	May 9, 2016
Publication date	Nov 9, 2017
Grant date	—

Abstract

Disclosed herein is a laser processing apparatus including a condenser having a function of spherical aberration. Since the condenser has a function of spherical aberration, the focal point of a laser beam to be focused by the condenser and applied to a wafer can be continuously changed in position along the thickness of the wafer. Accordingly, a uniform shield tunnel composed of a fine hole and an amorphous region surrounding the fine hole can be formed so as to extend from, the front side of the wafer to the back side thereof, by one shot of the laser beam.

First claim

What is claimed is:

1 . A laser processing apparatus comprising:
a chuck table for holding a wafer; laser beam applying means for applying a laser beam to said wafer held on said chuck table; and a feeding mechanism, for relatively feeding said chuck table and said laser beam applying means; said laser beam applying means including
a laser oscillator for oscillating said laser beam, and
a condenser having a focusing lens for focusing said laser beam oscillated by said laser oscillator and applying said laser beam focused to said wafer held on said chuck table;
said condenser having a function of spherical aberration such that a focal point to be formed by said laser beam passing through a radially inner portion of said condenser is continuously changed in position toward said chuck table from a focal point to be formed by said laser beam passing through a radially outer portion of said condenser; said laser beam being applied to said wafer in the condition where the focal point of said laser beam is set inside said wafer, so as to be continuously changed in position along the thickness of said wafer, thereby forming a shield tunnel inside said, wafer, said shield tunnel being composed of a fine hole and an amorphous region surrounding said fine hole.

2 . The laser processing apparatus according to claim 1 , wherein said function of spherical aberration is realized by said focusing lens having spherical aberration.

3 . The laser processing apparatus according to claim 1 , wherein said function of spherical aberration is realized by said focusing lens and a focal point correcting plate located between said focusing lens and said chuck table for correcting the position of the focal point of said laser beam to be focused by said focusing lens.

4 . The laser processing apparatus according, to claim 1 , wherein the range of change in position from the focal point to be formed by said laser beam passing through the radially outer portion of said condenser to the focal point to be formed by said laser beam passing through the radially inner portion of said condenser is set to 50 to 2000 μm.

Assignees

• Disco Corp

Inventors

• Kirihara Naotoshi

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P54/00 Primary

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• H10D64/011

  of electrodes ohmically coupled to a semiconductor · CPC title

• H10P90/00 Primary

  Preparation of wafers not covered by a single main group of this subclass, e.g. wafer reinforcement · CPC title

• B23K26/0853

  Devices involving movement of the workpiece in at least two axial directions, e.g. in a plane · CPC title