Chip manufacturing method

Abstract

The invention provides a method for manufacturing a chip, which can reliably divide a wafer by inhibiting abnormal extension of cracks and can reduce the number of times that the front surface and the back surface of the wafer are turned over. The chip manufacturing method comprises the following steps: a modified layer forming step of irradiating a first laser beam along a division predetermined line in a state that the back side of a substrate in a wafer having the substrate and a laminated body is exposed and the focal point of the first laser beam having a wavelength penetrating through the substrate is positioned in the substrate from the back side of the substrate, forming a modified layer and cracks; a grinding step of grinding the back surface side of the substrate exposed in the modified layer forming step after the modified layer forming step to thin the wafer to a predetermined thickness; and a laser processing groove forming step of irradiating a second laser beam having a wavelength absorbed by the substrate from the front surface side of the wafer along the division predetermined line after the grinding step, and forming a laser processing groove in the laminated body.

Description

technical field [0001] The present invention relates to a method of manufacturing a chip by dividing a wafer in which a substrate and a laminate are laminated to manufacture a chip. Background technique [0002] A semiconductor chip is usually a wafer having a substrate formed of a semiconductor such as silicon and a laminate such as a Low-k film and a conductive layer formed on the front surface of the substrate along a spacer (segmentation plan) set on the front surface of the substrate. line) is produced by dividing a wafer. In addition, TEGs (Test Element Groups) may be formed in some regions of the spacers in the laminate. [0003] In order to divide the wafer along the lanes, for example, first, a pulsed laser beam having a wavelength absorbed by the substrate and the laminate is irradiated along the lanes to form laser processing grooves along the lanes. The laminated body was partially removed by the laser processing groove, and the front surface of the substrate w...

AI Technical Summary

Problems solved by technology

[0006] However, when laser processing grooves are formed on a laminate, the crystal orientation of a part of the substrate near the bottom of the processing groove may change due to the thermal influence of the laser beam on the front side of the substrate.

[0007] The extending direction of the crack extending from the modified layer depends on the crystal orientation of the substrate. Therefore, when the crystal orientation changes, there is a problem that the crack is formed on the front surface of the substrate so as to avoid the laser-processed groove. Exposed, wafer cannot be divided along the spacer (ie, processing failure occurs)

[0009] However, after the modified layer is formed by exposing the back surface of the wafer upward, the laser processing groove is formed by exposing the front surface of the wafer upward, and then the substrate needs to be ground by exposing the back surface of the wafer upward again. During the period from the formation of the modified layer to the grinding, it is necessary to perform at least two operations of turning the front and back of the wafer, so the productivity is reduced

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