Cutting method for wafer

Abstract

The invention provides a cutting process of wafer. The said process can cheaply and simply keep cleaning effect without corroding the welding pad containing aluminium and divide the wafer into a number of semiconductor chips. In the said cutting process, cold machining water of below 15 degree mixed with carbon dioxide is supplied to wafer W through chemistry reaction with an eye to one reason of welding pad corroding, at the same time the cutting process of wafer W is performed using cutting tool (21), in order to slow the reaction rate of digesting of aluminium and prevent the welding pad from corrode.

Description

technical field [0001] The present invention relates to a wafer cutting method for dividing a wafer having bonding pads formed on its surface into individual semiconductor chips. Background technique [0002] A plurality of semiconductor wafers formed by dividing semiconductor chips such as ICs, LSIs, and CCDs at chip intervals are divided into individual semiconductor chips by a cutting device having a cutting tool. [0003] Here, since the cutting blade cuts into the wafer while rotating at a high speed during chip spacing cutting, cutting water is sprayed onto the contact portion to cool the contact portion between the wafer and the cutting blade. Moreover, the cutting water can prevent the cutting chips generated by cutting from adhering to the wafer, and at the same time, it can also play the role of removing the attached cutting chips and cleaning the surface of the wafer. If pure water is used as such cutting water, the specific resistance value will increase and sta...

AI Technical Summary

Problems solved by technology

[0005] However, there is a problem that the activated cutting water mixed with carbon dioxide has a strong acidity, and it corrodes the bonding pads formed on the surface of the semiconductor chip, especially the bonding pads mainly formed of aluminum, resulting in the ionization of aluminum and the occurrence of solder defects. Corrosion (leaching out) of pad leaching (液け出す), which degrades the quality of semiconductor chips

[0006] On the other hand, in the case where the concentration of carbon dioxide is adjusted low in order to suppress the corrosion of the parent metal or pad, the cleaning effect is not enough

[0007] Moreover, although there is also a method of suppressing the corrosion of the pad by using a cutting fluid containing a compound that forms an insulating coating on the surface of the pad in pure water (for example, refer to Patent Document 1), the price is high, and the cutting fluid The discharge method, piping, and cleaning of the device are complicated and unsuitable for practical use.

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