Method for 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 present invention relates to the technical field of semiconductor cleaning, and more specifically, to a method for improving the uniformity of DHF corrosion and controlling the corrosion rate during wet cleaning. Background technique [0002] The current single-chip 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 liquid to the surface of the rotating silicon wafer to achieve the cleaning of the silicon wafer. purpose. [0003] When the single-chip cleaning machine performs a process similar to DHF (hydrofluoric acid diluent) cleaning silicon wafers, the surface of the silicon wafers will change from hydrophilic to hydrophobic after the natural oxide layer on the surface of the silicon wafer is completely corroded by DHF, especially In the case of inconsistent DHF corrosion uniformity, defects such as particles on the surface...

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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

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