# US 10,246,782 B2 · Methods for etching a workpiece, an apparatus configured to etch a workpiece, and a non-transitory computer readable medium

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,246,782 B2
- Document ID: US10246782B2
- Status: Granted
- Kind: B2
- Application number: 14/735,209
- Filed: 2015-06-10
- Published: 2015-09-24
- Granted: 2019-04-02
- Earliest claimed: 2013-07-22
- Assignees: Infineon Technologies AG
- Applicants: Infineon Technologies AG
- Inventors: Karl Pilch; Sonja Muringer
- Web page: https://patentgrep.com/patent/US10246782B2

## CPC

- C23F 1/08: Apparatus, e.g. for photomechanical printing surfaces (photo- mechanical reproduction G03F)
- B05C 5/00: Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work (B05C7/00 takes precedence; essentially involving spraying or electrostatic projection B05B)
- B05C 11/00: Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00 (means for manipulating or holding work B05C13/00; enclosures for apparatus, booths B05C15/00; spray booths B05B16/00)
- B05D 1/00: Processes for applying liquids or other fluent materials (B05D5/00, B05D7/00 take precedence)
- B05D 1/002: {the substrate being rotated}
- C23F 1/14: Aqueous compositions
- H10F 99/00: Subject matter not provided for in other groups of this subclass
- H10P 50/642: {Chemical etching}
- H10P 72/0424: {using mainly spraying means, e.g. nozzles}
- H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects}
- H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes}
- C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08)
- B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02)
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method for etching a workpiece may be provided, which may include: determining a plurality of reference etch profiles for a plurality of positions of an etchant dispenser, each reference etch profile corresponding to a respective position of the plurality of positions of the etchant dispenser; determining a thickness profile of the workpiece; determining a respective etch duration for each position of the plurality of positions of the etchant dispenser based on the determined thickness profile and the plurality of reference etch profiles, to reduce a total thickness variation of the workpiece; and dispensing an etchant over the workpiece via the etchant dispenser for the determined respective etch duration for each position of the plurality of positions.

## Claims

### Claim 1

An apparatus configured to etch a workpiece, the apparatus comprising:
an etchant dispenser configured to dispense an etchant at a plurality of positions;
an etch profile determining circuit configured to determine a plurality of reference etch profiles, each reference etch profile corresponding to a respective position of the plurality of positions based on the etchant effects continuously across a reference workpiece corresponding to the etchant dispensed at the respective position;
a thickness determining circuit configured to determine a thickness profile of the workpiece, the thickness profile indicates the thicknesses of the workpiece continuously across the workpiece; and
an etch duration determining circuit configured to determine a respective etch duration for each position of the plurality of positions of the etchant dispenser based on the determined thickness profile and the plurality of reference etch profiles, to reduce a total thickness variation of the workpiece, each etch duration corresponding to a respective position of the plurality of positions.

### Claim 2 (depends on 1)

The apparatus of claim 1, further comprising:
a positioning device configured to position the etchant dispenser at the plurality of positions over the workpiece.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the etch duration determining circuit is configured to determine a linear combination of the plurality of reference etch profiles that reduces the total thickness variation of the workpiece, the respective etch duration being a respective coefficient corresponding to a respective reference etch profile of the linear combination of the plurality of reference etch profiles.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the etch duration determining circuit is configured to determine the linear combination of the plurality of reference etch profiles that reduces the total thickness variation of the workpiece by means of a least square fit.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the respective reference etch profile corresponding to the respective position comprises an etch profile that is obtained when material is etched from the reference workpiece in case the etchant dispenser is positioned at the respective position over the reference workpiece and the etchant is dispensed over the reference workpiece via the etchant dispenser.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the thickness determining circuit is configured to determine a thickness profile of the workpiece using at least one of a contactless measurement process and a contact measurement process.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the etch profile determining circuit is configured to:
a) determine an initial thickness profile of the reference workpiece indicating the thicknesses of the reference workpiece continuously across the reference workpiece;
b) position the etchant dispenser over the reference workpiece at a respective position of the plurality of positions;
c) dispense the etchant over the reference workpiece via the etchant dispenser for a predetermined reference etch duration corresponding to the respective position;
d) subsequently determine a final thickness profile of the reference workpiece indicating the thicknesses of the reference workpiece continuously across the reference workpiece;
e) determine a respective reference etch profile corresponding to the respective position from the determined initial thickness profile and the determined final thickness profile; and
f) carry out a)-e) for each position of the plurality of positions.

### Claim 8 (depends on 7)

The apparatus of claim 7, wherein e) comprises:
calculating the difference between the final thickness profile and the initial thickness profile and dividing by the predetermined reference etch duration corresponding to the respective position.

### Claim 9 (depends on 7)

The apparatus of claim 7, wherein the apparatus is further configured to spin the reference workpiece while dispensing the etchant over the reference workpiece.

### Claim 10 (depends on 7)

The apparatus of claim 7, wherein each etch reference profile is an etch rate determined continuously across the reference workpiece based on the final thickness profile, the initial thickness profile, and the predetermined reference etch duration corresponding to the respective position.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein a projection of the plurality of positions of the etchant dispenser onto a surface of the workpiece traces an arc passing through a center of the workpiece and disposed laterally within a boundary of the workpiece.

### Claim 12 (depends on 1)

The apparatus of claim 1, wherein the apparatus is further configured to:
move the etchant dispenser to a first position of the plurality of positions;
subsequently dispense the etchant over the workpiece for a respective etch duration determined for the first position;
subsequently move the etchant dispenser from the first position to a second position of the plurality of positions;
subsequently dispense the etchant over the workpieces for a respective etch duration determined for the second position; and
the apparatus is further configured to stop dispensing the etchant over the workpiece while moving the etchant dispenser from the first position to the second position of the plurality of positions.

### Claim 13 (depends on 1)

The apparatus of claim 1, wherein a respective position of the plurality of positions of the etchant dispenser is located at a respective height over a surface of the workpiece, the respective heights corresponding to the respective positions of the plurality of positions being at least substantially equal.

### Claim 14 (depends on 1)

The apparatus of claim 1, wherein each reference etch profile is based on the etch rate of the reference workpiece determined continuously along a line passing through the center of the reference workpiece.

### Claim 15 (depends on 1)

The apparatus of claim 1, wherein each thickness profile is based on the thicknesses of the workpiece determined continuously along a line passing through the center of the workpiece.

### Claim 16 (depends on 15)

The apparatus of claim 15, wherein the workpiece is a circular workpiece, and wherein the line passing through the center of the workpiece is a diameter of the circular workpiece.

### Claim 17 (depends on 1)

The apparatus of claim 1, wherein each reference etch profile is based on the amount of material removed from the reference workpiece determined continuously along a line passing through the center of the reference workpiece.

### Claim 18

An apparatus for etching a workpiece, the apparatus comprising:
a thickness determining circuit for determining a thickness profile of the workpiece, the thickness profile based on the thicknesses of the workpiece continuously across the workpiece, the workpiece having a total thickness variation;
an etchant dispenser for dispensing an etchant over the workpiece via the etchant dispenser;
a positioning device for positioning the etchant dispenser at a plurality of positions over the workpiece;
an etch profile determining circuit for determining a reference etch profile for each position of the plurality of positions, the reference etch profile for a respective position being a continuous etch profile that is obtained when material is etched from a reference workpiece in case the etchant dispenser is positioned at the respective position over the reference workpiece and an etchant is dispensed over the reference workpiece via the etchant dispenser; and
an etch duration determining circuit for determining an etch duration for each position of the plurality of positions based on the determined thickness profile of the workpiece and the determined reference etch profile for each position of the plurality of positions, the determined etch duration for a respective position being a duration of time the etchant is dispensed over the workpiece via the etchant dispenser positioned at the respective position, wherein the total thickness variation of the workpiece is reduced when dispensing the etchant over the workpiece via the etchant dispenser for the respective etch duration for the respective position.