Etching method for forming a carrier having inward side walls in particular for confining a droplet for capillary self-assembly

Patent metadata

Field	Value
Publication number	US-9586207-B2
Application number	US-201414903960-A
Country	US
Kind code	B2
Filing date	Jul 8, 2014
Priority date	Jul 9, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A method for capillary self-assembly of a plate and a carrier, including: forming an etching mask on a region of a substrate; reactive-ion etching the substrate, the etching using a series of cycles each including isotropic etching followed by surface passivation, wherein a duration of the isotropic etching for each cycle increases from one cycle to another, a ratio between durations of the passivation and etching of each cycle is lower than a ratio for carrying out a vertical anisotropic etching to form a carrier having an upper surface defined by the region and side walls defining an acute angle with the upper surface; removing the etching mask; placing a droplet on the upper surface of the carrier; and placing the plate on the droplet.

First claim

The invention claimed is:

1. A method for the capillary self-assembly of a plate and a carrier, comprising:
forming an etching mask on a region of a substrate;
reactive-ion etching the substrate, the reactive-ion etching comprising a series of cycles each including an isotropic etching followed by a surface passivation, wherein a duration of the isotropic etching for each cycle increases from one cycle to another, a ratio between durations of the surface passivation and isotropic etching of each cycle is lower than a ratio for carrying out a vertical anisotropic etching, to form a carrier having an upper surface defined by the region and side walls forming an acute angle with the upper surface;
removing the etching mask;
placing a droplet on the upper surface of the carrier; and
placing the plate on the droplet.

2. A method according to claim 1 , wherein the duration of the isotropic etching increases from 10% to 40% from one cycle to another.

3. A method according to claim 1 , wherein the ratio between the durations of the passivation and etching of each cycle is reduced from one cycle to another.

4. A method according to claim 1 , wherein the ratio between the durations of the passivation and etching is maintained constant from one cycle to another.

5. A method according to claim 1 , wherein the acute angle is less than 70°.

6. A reactive-ion etching method of etching a substrate to form a cavity having etching side walls forming an acute angle with a surface of the substrate, comprising:
a series of cycles, each cycle including an isotropic etching followed by a surface passivation;
wherein a duration of the isotropic etching of each cycle is progressively increased from one cycle to another; and
wherein a ratio between durations of the passivation and isotropic etching of each cycle is less than a ratio enabling a vertical anisotropic etching to take place.

Assignees

• Commissariat Energie Atomique
• St Microelectronics Crolles 2 Sas
• Commissariat L Energie Atomique Et Aux Energies Alternatives

Inventors

• Mermoz Sebastien
• Di Cioccio Lea
• Magis Thomas
• Sanchez Loic

Classifications

• H10P50/244

  comprising alternated and repeated etching and passivation steps · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W70/68

  Shapes or dispositions thereof · CPC title

• B81C1/00626 Primary

  Processes for achieving a desired geometry not provided for in groups B81C1/00563 - B81C1/00619 · CPC title

• B01L3/502

  with fluid transport, e.g. in multi-compartment structures · CPC title