Method for producing an integrated circuit pointed element comprising etching first and second etchable materials with a particular etchant to form an open crater in a project

Patent metadata

Field	Value
Publication number	US-11536872-B2
Application number	US-201916450365-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Nov 16, 2012
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A method of operating a mechanical switching device is disclosed. The switching device includes a housing, an assembly disposed in the housing, and a body. The assembly is thermally deformable and comprises a beam held in two different places by two arms secured to edges of the housing. The beam is remote from the body in a first configuration and in contact with and immobilized by the body in a second configuration. The assembly has the first configuration at a first temperature and the second configuration when one of the arms has a second temperature different from the first temperature. The method includes exposing an arm of the assembly to the second temperature, and releasing the beam using a release mechanism. The release mechanism includes a pointed element comprising a pointed region directed towards the body. The pointed element limits an open crater in a concave part of a projection.

First claim

What is claimed is:

1. A method of operating a mechanical switching device in a Back End Of Line (BEOL) region of a semiconductor device, the switching device comprising
a housing,
an assembly disposed in the housing, the assembly being thermally deformable and comprising a beam held in two different places by two arms secured to edges of the housing, and
an electrically conductive body, the beam being remote from the electrically conductive body in a first configuration and in contact with the electrically conductive body and immobilized by the electrically conductive body in a second configuration, wherein the assembly has the first configuration when it has a first temperature and the second configuration when one of the two arms has a second temperature that is different from the first temperature, the method comprising:
exposing one of the two arms of the assembly to the second temperature; and
releasing, by a release mechanism, the beam being immobilized by the electrically conductive body, the release mechanism comprising a pointed element comprising a pointed region directed towards the electrically conductive body, the pointed element limiting an open crater in a concave part of a projection of the release mechanism.

2. The method of claim 1 , wherein the beam and the arms are metallic and located within one and the same first metallization level.

3. The method of claim 1 , further comprising generating an electrostatic field at a metallization level of the pointed region.

4. The method of claim 1 , wherein the beam does not conduct electricity when in the first configuration.

5. The method according to claim 1 , wherein the release mechanism underlies the electrically conductive body, and wherein releasing the beam comprises releasing the beam from the electrically conductive body using a repulsion effect.

6. The method according to claim 1 , wherein exposing one of the two arms of the assembly to the second temperature comprises exposing the entire mechanical switching device to the second temperature.

7. A method of operating a mechanical switch, the method comprising:
exposing the mechanical switch in a Back End Of Line (BEOL) region of a semiconductor device to an ambient temperature,
wherein an assembly of the mechanical switch is in a first configuration at the ambient temperature, and
wherein the assembly is disposed in a housing and comprises a beam held in two different places by a first arm and a second arm, each secured to edges of the housing, the first arm being attached to an upper surface of a first distal end of the beam, and the second arm being longitudinally offset from the first arm and attached to a lower surface of the first distal end, a second distal end of the beam being free in the first configuration;
operating an integrated circuit of the semiconductor device;
exposing the mechanical switch to an elevated temperature due to operating the integrated circuit; and
thermally deforming the two arms of the assembly from the first configuration to a second configuration in response to the elevated temperature.

8. The method according to claim 7 , wherein the beam and the two arms are metallic and located within a first metallization level.

9. The method according to claim 7 , further comprising:
exposing the mechanical switch to the ambient temperature after thermally deforming the assembly;
releasing the beam from the second configuration by generating an electrostatic field at an electrically conductive body attached to the housing and comprising a metallic appendage;
wherein the beam is remote from the electrically conductive body at the ambient temperature; and
wherein the beam is in contact with and immobilized by the metallic appendage of the electrically conductive body at the elevated temperature.

10. The method according to claim 9 , wherein:
the beam and the two arms are metallic and located within a first metallization level;
the electrically conductive body is located in a second metallization level; and
the metallic appendage is a via located between the first metallization level and the second metallization level.

11. The method according to claim 7 , wherein the beam is immobilized in the second configuration.

12. The method according to claim 7 , wherein the beam does not conduct electricity when in the first configuration.

13. The method of claim 7 , wherein releasing the beam from the second configuration comprises generating the electrostatic field using a release mechanism underlying the electrically conductive body to repel the electrically conductive body.

14. A method of operating a mechanical switching device in a Back End Of Line (BEOL) region of a semiconductor device, the switching device comprising
a housing,
an assembly disposed in the housing, the assembly being thermally deformable and comprising a beam held in two different places by two arms secured to edges of the housing, and
an electrically conductive body, the beam being remote from the electrically conductive body in a first configuration and in contact with the electrically conductive body and immobilized by the electrically conductive body in a second configuration, wherein the assembly has the first configuration when it has a first temperature and the second configuration when one of the two arms has a second temperature that is different from the first temperature, the method comprising:
exposing one of the two arms of the assembly to the second temperature; and
releasing, by a release mechanism, the beam being immobilized by the electrically conductive body, the release mechanism comprising a pointed element comprising a pointed region directed towards the electrically conductive body, the pointed element limiting an open crater in a concave part of a projection of the release mechanism; and
wherein the beam in contact with and immobilized by the electrically conductive body in the second configuration is immobilized by a metallic appendage of the electrically conductive body attached to the housing.

15. The method of claim 14 , wherein the beam and the arms are metallic and located within one and the same first metallization level.

16. The method of claim 15 , wherein the electrically conductive body is located in a second metallization level.

17. The method of claim 16 , wherein the metallic appendage is a via located between the first metallization level and the second metallization level.

18. The method of claim 14 , wherein the beam does not conduct electricity when in the first configuration.

19. The method of claim 14 , wherein the release mechanism underlies the electrically conductive body, and wherein releasing the beam comprises releasing the beam from the electrically conductive body using a repulsion effect.

20. The method of claim 19 , wherein using the repulsion effect comprises generating an electrostatic field at a metallization level of the pointed region.

21. The method of claim 14 , wherein exposing one of the two arms of the assembly to the second temperature comprises exposing the entire mechanical switching device to the second temperature.

Assignees

• St Microelectronics Rousset

Inventors

• Marzaki Abderrezak
• Goasduff Yoann
• Bidal Virginie
• Fornara Pascal

Classifications

• B81B2201/0242

  Gyroscopes · CPC title

• B81C1/00111

  Tips, pillars, i.e. raised structures (microneedles A61M37/0015) · CPC title

• B81B3/001 Primary

  Structures having a reduced contact area, e.g. with bumps or with a textured surface · CPC title

• B81B2201/0235

  Accelerometers · CPC title

• B81B2203/0361

  Tips, pillars · CPC title