Method and device for laser processing wafer

Abstract

The invention provides a laser processing method and device for wafer. The method is characterized in that at least two laser light beams are focused and gathered to one point to form a focus point through a focusing element. The method comprises the following steps that: at least two laser light beams between the focusing element and the focus point separately etch the two sides of a predetermined cutting path on the upper surface of the wafer in a high-frequency form to form grooves; and the focus point of the laser light beams etches a gap between the grooves in a low-frequency form. In case of keeping power of the laser light beams emitted by a laser unit unchanged, purposes of etching the predetermined cutting path and the gap are separately realized by changing focal depth positions of at least two laser light beams, so that the structure of the processing device is simplified, processing precision and stability of the laser light beams are improved, and wafer processing effect is improved; and meanwhile, the effect of simplifying the device further can be realized to adapt to production and popularization.

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, when the process of processing grooves with low power and processing slits with high power is realized by adjusting the power, the laser beam fluctuates due to the ripple effect of the laser when the power is adjusted, and the etching accuracy of this process is low.

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