A method of improving DHF corrosion uniformity and controlling corrosion rate

Abstract

The invention discloses a method for improving DHF (Dilute Hydrofluoric Acid) corrosion uniformity and controlling a corrosion rate. According to the invention, a silicon wafer is disposed on a rotary clamping structure in a processing chamber for DHF cleaning in a single-wafer cleaning machine. The rotation speed of the silicon wafer can be adjusted through a technique menu for being corresponding to techniques of different time periods in a single step. In the first DHF cleaning step, DHF can be distributed on the surface of the silicon wafer uniformly, so that exchange of new soup and old soup can be accelerated and corrosion efficiency and corrosion uniformity can be improved. In the second deionized water cleaning step, residue DHF on the surface of the silicon wafer can be thrown away and deionized water can cover the surface of the silicon wafer quickly, so that corrosion uniformity of the surface of the silicon wafer after the DHF cleaning technique can be improved and the corrosion rate is controllable at the same time.

Description

technical field [0001] The invention relates to the technical field of semiconductor cleaning, in particular to a method for improving DHF corrosion uniformity and controlling corrosion rate during wet cleaning. Background technique [0002] The current single-wafer cleaning machine uses the clamping structure (chuck) of its process chamber to drive the silicon wafer to rotate at a high speed, and then uses the spray arm to spray the chemical solution to the surface of the rotating silicon wafer to achieve the cleaning efficiency of the silicon wafer. Purpose. [0003] When the single-chip cleaning machine is doing a process similar to DHF (diluted hydrofluoric acid) to clean silicon wafers, since DHF completely corrodes the natural oxide layer on the surface of the silicon wafer, the surface of the silicon wafer will change from hydrophilic to hydrophobic, especially In the case of inconsistent DHF etching uniformity, defects such as particles on the surface of the silicon...

AI Technical Summary

Problems solved by technology

The inventors have found that if the silicon wafer is kept at a constant speed in one process step, it is difficult to combine the characteristics of different process steps, which is not conducive to the uniformity of DHF corrosion, and it is also difficult to prompt the old chemical solution and reaction products to leave in time. The surface of the silicon wafer, resulting in a sharp increase of particles on the surface of the silicon wafer

Images