Substrate etch

Patent metadata

Field	Value
Publication number	US-9695515-B2
Application number	US-201314913771-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Aug 30, 2013
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

An example provides a method including providing a substrate including an area having a plurality of pores and etching the area of the substrate to remove the plurality of pores to form a recess in the substrate. In some examples, the recess may form, at least in part, a device.

First claim

What is claimed is:

1. A method comprising:
arranging a mask with a plurality of openings on a surface of a substrate;
depositing metal on the surface of the substrate through the plurality of openings to form a metal layer;
arranging another mask with a plurality of openings on an opposite side of the substrate;
depositing metal on the opposite side of the substrate through the mask on that opposite side of the substrate prior to etching the substrate;
etching the substrate using a solution that reacts with the metal layer to form a plurality of pores in the substrate; and
etching the substrate to remove the plurality of pores to form a recess in the substrate.

2. The method of claim 1 , wherein the metal layer is a discontinuous metal layer.

3. The method of claim 1 , wherein the mask is a silicon carbide hard mask.

4. The method of claim 1 , further comprising removing the mask after said depositing the metal.

5. The method of claim 4 , wherein said removing is performed prior to said etching the substrate using the solution.

6. The method of claim 1 , wherein the metal layer comprises a metal selected from a group consisting of gold silver, platinum, ruthenium, platinum, palladium, molybdenum, chromium, copper, tantalum, titanium, tungsten, and alloys thereof.

7. The method of claim 1 , wherein the solution comprises hydrogen peroxide, hydrofluoric acid, and water.

8. The method of claim 1 , wherein the recess comprises a trench, a blind hole, or a through-hole.

9. The method of claim 1 , wherein the recess has a width greater than about 20 μm.

10. The method of claim 1 , wherein the substrate comprises silicon.

11. The method of claim 1 , wherein depositing metal through the plurality of openings of the mask further comprises blanket depositing metal over the mask.

12. The method of claim 1 , wherein the mask comprises a photoresist material.

13. The method of claim 1 , further comprising agitating a bath in which the substrate is etched.

14. The method of claim 1 , further comprising illuminating the substrate during etching with ultraviolet or optical wavelengths that increase the efficiency of the etching.

15. The method of claim 1 , further comprising controlling a sidewall profile of the etch in the substrate to form the plurality of pores in the substrate by controlling a ratio of nitric acid to hydrogen peroxide in the solution.

16. A method comprising:
forming a metal layer on a surface of a substrate by depositing metal on a substrate through a plurality of openings of a mask;
etching the substrate using a solution that reacts with the metal layer to form a plurality of pores in the surface in the substrate; and
etching the substrate to remove the plurality of pores to form a micro-electrical-mechanical-systems (MEMS) device;
wherein the surface is a first surface, and wherein the method further comprises:
forming another metal layer on an area of a second surface, opposite the first surface, of the substrate by depositing metal on the substrate through a plurality of openings of another mask;
etching the substrate using the solution to form another plurality of pores in the second surface in the substrate; and
etching the substrate to remove the other plurality of pores to further form the MEMS device.

17. The method of claim 16 , further comprising forming a printhead with the MEMS device.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Mckay Jr Roger A
• Sadik Patrick

Classifications

• B41J2/1631

  photolithography · CPC title

• B81C1/00119

  Arrangement of basic structures like cavities or channels, e.g. suitable for microfluidic systems · CPC title

• B41J2/1609 Primary

  of finger type, chamber walls consisting integrally of piezoelectric material · CPC title

• B41J2/1629

  wet etching · CPC title

• B81B2201/052

  Ink-jet print cartridges · CPC title