Laser etching and trench digging method of semiconductor chip

Abstract

The invention relates to a method for laser etching trenching of a semiconductor wafer, characterized in: a semiconductor wafer surface is vertically radiated by a laser beam, with the relative movement between the laser beam and the semiconductor wafer, the laser beam etches the material on the surface of the radiation area by way of melting and evaporating, thus to form a trench on the semiconductor wafer surface; the laser beam is ultraviolet laser, the wavelength is 200 to 400nm, the frequency is 30 to 50 KHz, the single pulse energy is 100 to 200 mJ. The invention relates to the field of semiconductor manufacture technology, which is environment-friendly and efficient, overcomes the drawbacks of past method that trenches by wet etching or dry etching, improves the accuracy, stability and uniformity, lowers the cost, and enriches the processing technology for surface etching trenching of semiconductor wafer.

Description

technical field [0001] The invention relates to semiconductor manufacturing technology, in particular to a method for using laser etching to open grooves on the surface of a semiconductor wafer. The method is not only environmentally friendly and efficient, but also simplifies the processing technology of traditional semiconductor surface ditching, improves the ditching accuracy, and reduces the cost. Background technique [0002] In the semiconductor chip processing technology, several main steps such as oxidation, deposition, photolithography, etching, ion implantation and metallization are widely used, and trenching on the semiconductor wafer is an indispensable process method after pattern exposure. [0003] In the prior art, the so-called trenching is to use the geometric patterns on the mask (Mask) to transfer the patterns to the photosensitive film (photoresist) covered on the semiconductor wafer through photochemical reaction. These patterns can define various aspect...

AI Technical Summary

Problems solved by technology

However, in dry etching, the residual oxygen will etch the photoresist, and the temperature in the reaction chamber can be as high as 200°C. A certain high temperature can bake the photoresist to a state that is difficult to remove from the wafer. The temperature effect will also deform the pattern due to the flow tendency. An undesirable effect in plasma etching is that the photoresist will even become a side polymer deposited on the side of the etched pattern. Ion beam etching, which belongs to the physical process The selectivity of etch ion grinding is very poor, and the radiation damage due to ionization is also a problem

Images