Integrated mechanical device with vertical movement

Patent metadata

Field	Value
Publication number	US-10157720-B2
Application number	US-201414517369-A
Country	US
Kind code	B2
Filing date	Oct 17, 2014
Priority date	Oct 29, 2013
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

A device includes a thermally deformable assembly accommodated in a cavity of the interconnection part of an integrated circuit. The assembly can bend when there is a variation in temperature, so that its free end zone is displaced vertically. The assembly can be formed in the back end of line of the integrated circuit.

First claim

What is claimed is:

1. An integrated circuit, comprising:
a substrate;
an interconnection region overlying the substrate, the interconnection region comprising a plurality of metallization levels and a via level;
a device comprising a thermally deformable electrically conductive assembly extending at least partly in a cavity of the interconnection region, the device further comprising a free end zone that is mobile in the cavity in a movement direction substantially perpendicular to mid-planes of the metallization levels, and a fixed end zone, opposite the free end zone, that is located outside the cavity, the thermally deformable electrically conductive assembly comprising:
a first element located within a first metallization level of the plurality of metallization levels, the first element extending from the fixed end zone into the cavity;
a second element secured to an underside of the first element and located within the via level, which is adjacent to the first metallization level, the second element extending from the fixed end zone into the cavity, the first element and the second element respectively having materials with different coefficients of thermal expansion, wherein a length of the first element is greater than a length of the second element; and
an electrically conductive body arranged at least partly in the cavity, the thermally deformable electrically conductive assembly having different configurations corresponding respectively to different distances along a direction between the free end zone and the electrically conductive body, the thermally deformable electrically conductive assembly being activatable in order to change from one configuration to another, wherein one of the configurations corresponds to a zero distance such that only the first element at the free end zone is in physical contact with the electrically conductive body so as to establish an electrical connection passing through the electrically conductive body and the thermally deformable electrically conductive assembly.

2. The integrated circuit according to claim 1 , wherein the first element comprises aluminum and the second element comprises tungsten.

3. The integrated circuit according to claim 1 , wherein the first element comprises a first metal that is the same as the metal of the first metallization level, and the second element comprises at least one metal portion having a second metal that is different than the first metal.

4. The integrated circuit according to claim 3 , wherein the first metal comprises aluminum and the second metal comprises tungsten.

5. The integrated circuit according to claim 1 , wherein the first element of the thermally deformable electrically conductive assembly is U-shaped having two parallel branches connected by a connecting branch.

6. The integrated circuit according to claim 5 , wherein the free end zone of the thermally deformable electrically conductive assembly includes the connecting branch and wherein the second element of the thermally deformable electrically conductive assembly has a straight portion extending under each of the two parallel branches as far as the free end zone.

7. The integrated circuit according to claim 1 , wherein the thermally deformable electrically conductive assembly is thermally activatable.

8. The integrated circuit according to claim 1 , wherein the thermally deformable electrically conductive assembly is electrically activatable, the first element being configured in order to allow an electrical current to flow through it at least partly, in order to increase its temperature.

9. The integrated circuit according to claim 8 , further comprising a voltage generator coupled to apply an electrical voltage between two points of the first element so as to generate the current.

10. The integrated circuit according to claim 1 , wherein a width of the first element is constant along the length of the first element, and wherein a width of the second element is constant along the length of the second element.

11. An integrated circuit, comprising:
a semiconductor substrate;
integrated circuitry disposed at an upper surface of the semiconductor substrate;
a device overlying the substrate and spaced from the integrated circuitry, the device comprising:
a first element formed in a cavity in an insulating region overlying the semiconductor substrate, the first element having a fixed end zone that is located outside the cavity and a free end zone that is located inside the cavity and is mobile relative to the fixed end zone and movable in a movement direction substantially perpendicular to the upper surface of the semiconductor substrate;
a second element secured to the fixed end zone of the first element and extending into the cavity, the second element being secured to an underside of the first element, the second element having a material with a different coefficient of thermal expansion than a material of the first element, wherein a length of the first element is greater than a length of the second element; and
an electrically conductive body adjacent the free zone of the first element, the device having different configurations corresponding to different distances along a direction between the free end zone and the electrically conductive body, one of the different configurations being a zero distance configuration in which only the first element physically contacts the electrically conductive body.

12. The integrated circuit according to claim 11 , wherein the device has different configurations based on temperature.

13. The integrated circuit according to claim 11 , wherein the device has different configurations based on an electrical current flowing through the first element.

14. The integrated circuit according to claim 11 , wherein the first element comprises aluminum and the second element comprises copper.

15. The integrated circuit according to claim 11 , wherein the first element is formed in a first metallization level and the second element is formed in a first via level, the first metallization level and the first via level having other portions that form at least part of an interconnect structure that electrically connects portions of the integrated circuitry.

16. The integrated circuit according to claim 11 , wherein the first element of the device is U-shaped having two parallel branches connected by a connecting branch.

17. The integrated circuit according to claim 11 , wherein a width of the first element is constant along the length of the first element, and wherein a width of the second element is constant along the length of the second element.

Assignees

• St Microelectronics Rousset

Inventors

• Rivero Christian
• Fornara Pascal
• Di-Giacomo Antonio
• Arrazat Brice

Classifications

• B81B2201/031

  Thermal actuators · CPC title

• H01H9/02

  Bases, casings, or covers (accommodating more than one switch or a switch and another electrical component H02B1/26) · CPC title

• H01H61/02 Primary

  wherein the thermally-sensitive member is heated indirectly, e.g. resistively, inductively · CPC title

• H01H1/58

  Electric connections to or between contacts; Terminals {(for high tension switches H01H33/025; for electromagnetic relays H01H50/14; for circuit breakers H01H71/08)} · CPC title

• B81B2203/053

  Translation according to an axis perpendicular to the substrate · CPC title