Method for synchronous wet etching processing of differential microstructures

Abstract

A method for synchronous wet etching processing of differential microstructures, including the following steps: step a: performing photoetching on a processing surface of a workpiece to be processed to develop the workpiece; step b: affixing a mask to a surface opposite to the processing surface of the workpiece; step c: continuously cooling the mask; step d: placing the cooled mask and the workpiece in a wet etching device; and adding an etchant to the processing surface of the workpiece to start etching; step e: removing the mask and the workpiece from the wet etching device after the set etching time; separating the mask and the workpiece to obtain a workpiece with a etching structure. A temperature difference is formed between the pattern area to be processed and the retaining area.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of priority from Chinese Patent Application No. CN201810338811.0, filed on Apr. 16, 2018. The content of the aforementioned application, including any intervening amendments thereto, is incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The present disclosure relates to micro-nano manufacturing, and more particularly to a method for synchronous wet etching processing of differential microstructures.BACKGROUND OF THE INVENTION[0003]Wet etching is a processing means commonly used in the micro-nano processing. Chemical reagents are adopted in the wet etching to etch or dissolve the material to be processed so as to remove the materials. The wet etching rate is associated with the reaction type and is also highly susceptible to the reaction temperature. The wet etching can be performed in the case where a reagent capable of etching and dissolving the material to be processed is available....

AI Technical Summary

Benefits of technology

The present invention provides a method for processing microstructures on silicon wafers using a synchronous wet etching process. The method includes steps of photoetching and developing a pattern, affixing a mask with the same pattern to the opposite surface of the wafer, cooling the mask with liquid nitrogen, adding an etchant, and creating a temperature difference between the pattern area and the retaining area on the wafer to achieve faster etching and a higher depth-to-width ratio for micro vias and grooves. The method ensures high processing accuracy and precision.

Problems solved by technology

The wet etching rate is associated with the reaction type and is also highly susceptible to the reaction temperature.

However, certain limitations still exist in the wet etching.

For example, when a single crystal silicon is etched by a typical TMAH solution or KOH solution, the etching direction of is presented as 54.7° on the surface of the workpiece, making it difficult to obtain the smooth vertical vias or grooves.

In addition, micro vias and grooves with different sizes cannot be processed on the same workpiece.

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