Method and device for laser processing wafer

Abstract

The invention provides a laser machining method and device for a wafer. The method comprises that at least two laser beams having different energy distribution respectively execute a hacking process and a grooving process on a predetermined cutting path on the upper surface of the wafer in sequence and are used for forming a groove in the predetermined cutting path on the upper surface of the wafer. The predetermined cutting path on the upper surface of the wafer can be hacked by the laser beams with lower energy, the surface of the predetermined cutting path is roughened to improve a light absorptivity, which is convenient for preparation for a subsequent machining process, and the wafer is prevented from being damaged by stripping of a Low-K material caused by a fact that a Low-K layer on the surface of the wafer is machined by adopting the laser beams with over high energy; and meanwhile, the control precision on the energy of the laser beams in a subsequent machining process is higher, and further a laser machining effect of the upper surface of the wafer is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor processing, in particular to a method and device for laser processing wafers. Background technique [0002] In recent years, with the continuous reduction of the feature size of semiconductor devices and the continuous improvement of chip integration, the parasitic capacitance between metal interconnections and multilayer wiring and the resistance of metal wires have increased sharply, resulting in RC delays, A series of problems such as increased power consumption limit the development of high-speed electronic components. When the feature size of the device is smaller than 90nm, the wafer must use low dielectric constant material instead of traditional SiO 2 Layer (K ​​= 3.9 ~ 4.2), commonly used Low-K materials include Dow Corning's FOx and porous SiLK materials, Applied Materials' black diamond series low-K thin film materials, Novellus System's CORAL, Intel's CDO and NEC's FCN+ organic...

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Problems solved by technology

[0004] However, since the Low-K layer on the upper surface of the wafer is made of a transparent material, it causes a large amount of reflection and transmission of the laser beam during laser processing, resulting in a large amount of energy loss. Therefore, it is necessary to increase the laser energy for slotting, which in turn leads to Low-K Layers are prone to peeling off and the heat-affected zone is large

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