Laser cutting and ring removing method for wafer

Abstract

The invention discloses a laser cutting and ring removing method for a wafer. The laser cutting and ring removing method comprises the following steps that 1, the wafer is placed and fixed to a cutting table; 2, an incident laser beam emitted by a laser emitter is divided into a reflected laser beam and a refracted laser beam through a spectroscope; and 3, the edge ring of the wafer is cut and removed by adopting the reflected laser beam or the refracted laser beam, and the heat effect in the cutting process is reduced by utilizing the characteristic that the energy of the reflected laser beam or the refracted laser beam is lower than that of the incident laser beam. According to the laser cutting and ring removing method, the width of the laser cutting light beam can be increased, the laser cutting light beam is ensured to have lower energy so that the heat effect in the cutting process can be reduced, ablative substances are prevented from splashing to the surface of the wafer on the inner side of the edge ring, adverse effects on effective chip crystal grains of the wafer can be prevented, and meanwhile, the wider laser cutting light beam is beneficial to cutting of the thinner wafer without generating micro cracks.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit manufacturing process method, in particular to a laser cutting ring cutting method for a wafer. Background technique [0002] In the manufacture of semiconductor integrated circuits, the wafer often needs to be thinned to improve the performance of the device. After the wafer is thinned, the edge ring of the wafer needs to be cut and removed. The wafer thinning process includes a Taiko thinning process. The Taiko thinning only thins the middle area of ​​the wafer, and the edge area of ​​the wafer is not thinned but serves as a support ring. [0003] Cutting processes for edge rings of wafers include laser cutting, such as figure 1 As shown, it is a schematic diagram of laser cutting in the laser cutting and ring removal method of the existing wafer; the laser cutting and ring removal method of the existing wafer includes the following steps: [0004] Step 1, placing and fixing the wafer 102 ...

AI Technical Summary

Problems solved by technology

[0011] However, as the thinner sheet technology develops, it will cause microcracks in the effective area during the Ring Remove process; if a wider laser beam is simply selected, the thermal effect per unit time will increase rapidly, causing a large amount of ablation to splash into the ring. On the effective chip die (die) at the center and edge of the wafer and cause an irreversible thermal reaction to the effective die

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