# US 2019/0355587 A1 · Method for synchronous wet etching processing of differential microstructures

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- Number: US 2019/0355587 A1
- Document ID: US20190355587A1
- Status: Published application
- Kind: A1
- Application number: 16/383,885
- Filed: 2019-04-15
- Published: 2019-11-21
- Earliest claimed: 2018-04-16
- Assignees: Guangdong University of Technology
- Applicants: Guangdong University of Technology
- Inventors: Xin CHEN; Yun CHEN; Dachuang SHI; Xun CHEN; Qiang LIU; Jian GAO; Chengqiang CUI
- Web page: https://patentgrep.com/patent/US20190355587A1

## CPC

- H10P 50/644: {Anisotropic liquid etching (H10P50/61 takes precedence)}
- H10P 50/694: {characterised by their behaviour during the process, e.g. soluble masks or redeposited masks}
- H10P 50/642: {Chemical etching}
- H10P 50/693: {characterised by their size, orientation, disposition, behaviour or shape, in horizontal or vertical plane}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## 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.

## Claims

### Claim 1

A method for synchronous wet etching processing of differential microstructures, comprising:
step a: performing photoetching on a processing surface of a workpiece to be processed to develop the processing surface of the workpiece; wherein a pattern area to be processed on the processing surface of the workpiece to be processed is exposed, and a pattern area without processing is covered by a photoresist layer;
step b: affixing a mask to a surface of the workpiece, opposite to the processing surface; wherein a processing pattern on the mask has the same shape as and aligns with the pattern area to be processed on the processing surface;
step c: continuously cooling the mask affixed to the surface of the workpiece;
step d: placing the cooled mask and the workpiece to be processed in a wet etching device; and adding an etchant to the processing surface of the workpiece to start etching;
step e: setting an etching time; then removing the mask and the workpiece from the wet etching device after the set etching time; stopping the etching; separating the mask and the workpiece to obtain a workpiece with a etching structure.

### Claim 2 (depends on 1)

The method of claim 1, wherein in step a, the workpiece to be processed is a wafer made of silicon.

### Claim 3 (depends on 1)

The method of claim 1, wherein in step a, the photoresist layer is 10 nm-10 μm in thickness.

### Claim 4 (depends on 1)

The method of claim 1, wherein in step b, the mask comprises a light shielding layer and a base layer; the base layer is made of stainless steel or copper.

### Claim 5 (depends on 1)

The method of claim 1, wherein in step c and/or step d, the mask is continuously cooled by flowing liquid nitrogen.

### Claim at position 6 (depends on 1)

The method of claim 1, wherein in step d, the etchant is a TMAH etching solution or a KOH etching solution

### Claim 7 (depends on 1)

The method of claim 1, wherein in step e, the etching time is set as 5 min to 5 h.

### Claim 8 (depends on 1)

The method of claim 1, wherein in step e, a depth-to-width ratio of micro vias or grooves in the etching structure is greater than 5.