Wafer processing method

Patent metadata

Field	Value
Publication number	US-9748182-B2
Application number	US-201615370638-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Dec 7, 2015
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Disclosed herein is a wafer processing method including a stacked member removing step of applying a laser beam having an absorption wavelength to a stacked member through a protective film along each division line formed on the front side of a wafer, thereby performing ablation to remove the stacked member present on each division line, a dividing step of applying an external force to the wafer to divide the wafer into individual device chips along each division line where a modified layer is previously formed, and a plasma etching step of supplying an etching gas in a plasma state to the wafer from the front side thereof after performing the stacked member removing step or after performing the dividing step, thereby removing damage due to the ablation in the stacked member removing step.

First claim

What is claimed is:

1. A wafer processing method for dividing a wafer into a plurality of individual device chips along a plurality of crossing division lines formed on a front side of said wafer, the front side of said wafer being partitioned by said division lines to define a plurality of separate regions where a plurality of devices are formed, said individual device chips corresponding to said devices, said wafer having a stacked member formed thereon, said wafer processing method comprising:
a protective member attaching step of attaching a protective member to the front side of said wafer;
a back grinding step of grinding a back side of said wafer after performing said protective member attaching step, thereby reducing the thickness of said wafer to a predetermined thickness;
a modified layer forming step of applying a laser beam having a transmission wavelength to said wafer from the back side thereof along each division line in the condition where the focal point of said laser beam is set inside said wafer after performing said back grinding step, thereby forming a modified layer inside said wafer along each division line;
a wafer supporting step of attaching the back side of said wafer to an adhesive tape supported at its peripheral portion to an annular frame having an inside opening capable of receiving said wafer after performing said modified layer forming step, thereby supporting said wafer through said adhesive tape to said annular frame, and next peeling said protective member from the front side of said wafer;
a protective film forming step of applying a water-soluble resin to the front side of said wafer after performing said wafer supporting step, thereby forming a protective film from said water-soluble resin;
a stacked member removing step of applying a laser beam having an absorption wavelength to said stacked member through said protective film along each division line after performing said protective film forming step, thereby performing ablation to remove said stacked member present on each division line;
a dividing step of applying an external force to said wafer after performing said stacked member removing step, thereby dividing said wafer into said individual device chips along each division line where said modified layer is formed;
a protective film removing step of cleaning the front side of said wafer after performing said dividing step, thereby removing said protective film from the front side of said wafer; and
a plasma etching step of supplying an etching gas in a plasma state to said wafer from the front side thereof after performing said stacked member removing step or after performing said dividing step, thereby removing damage due to the ablation in said stacked member removing step.

Assignees

• Disco Corp

Inventors

• Nakamura Masaru

Classifications

• H10P72/7442

  Separation by peeling · CPC title

• H10P72/7422

  used to protect an active side of a device or wafer · CPC title

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P74/27

  Structural arrangements therefor · CPC title

• H10P72/7402

  Wafer tapes, e.g. grinding or dicing support tapes · CPC title