Corrosion method for reducing defects on back surface of germanium substrate wafer

Abstract

The invention discloses a corrosion method for reducing defects on the back surface of a germanium substrate wafer; the method comprises the following steps: inserting a germanium substrate wafer into a slot of a clamping plug, immersing the germanium substrate wafer into corrosive liquid for corrosion, and sequentially performing washing with deionized water and performing spin-drying to finish corrosion; the clamping plug is provided with 25 slots from an H head to a U head, a gasket is inserted into at least the first slot from the H head, a gasket is inserted into at least the first slot from the U head, and the gaskets are Teflon plastic gaskets and / or waste germanium gaskets; the corrosive liquid comprises hydrofluoric acid, nitric acid, hydrogen peroxide, glacial acetic acid and bromine in a volume ratio of (300-500): (500-800): (50-100): (300-1000): (3-9). According to the invention, through the combination of solution improvement, gasket addition and other schemes, the back defects in the corrosion process of the germanium substrate wafer are effectively reduced, the repair rate and the incapacity rate are further reduced, the back corrosion quality is improved, the corrosion consistency of the substrate wafer is improved, and the strength of the wafer is integrally improved; the operation is simplified, the production efficiency is improved, and the production cost is reduced.

Description

Technical field[0001]The present invention relates to a method of lowering the back defect of the ruthenium substrate wafer, belonging to the field of germanium semiconductor substrate processing.Background technique[0002]The germanium substrate wafer is mainly divided into three types of PD, PE and PP, of which 98% is small in PD formula, PE and PP formula wafers. During the manufacturing process, in order to eliminate the stress of the wafer, improve the strength of the wafer, there will be corrosion process steps. The back surface of the wafer are PD and PE as the final etching process, there will be no other processing demands placed on the rear surface is relatively high, the drug does not allow printing, etching unevenness, jammed printing, wave pattern, scratches and other Defects.[0003]Germanium substrate wafer etch process generally hydrofluoric acid - nitric acid etching liquid, the etching process uses corrosion resistant Teflon material jam (H U header to the head of 25 ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the corrosion liquid reacts violently with the substrate wafer, the temperature of the chemical rises rapidly, and requires high experience and techniques of employees, and defects such as chemical marks, uneven corrosion, jam marks, and wavy patterns are easily produced on the back

When the defects on the back of the wafer do not meet the shipping standard, it needs to be reworked (PD) or polished (PE), and it needs to be etched again, resulting in a reduction in the thickness of the wafer or even infinite

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