MEMS heater or emitter structure for fast heating and cooling cycles

Patent metadata

Field	Value
Publication number	US-11245064-B2
Application number	US-201916379107-A
Country	US
Kind code	B2
Filing date	Apr 9, 2019
Priority date	Apr 1, 2016
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

According to various embodiments, a MEMS device includes a substrate, an electrically movable heating element having a first node coupled to a first terminal of a first voltage source and the second node coupled to a reference voltage source, a first anchor anchoring the first node and a second anchor anchoring the second node of the electrically movable heating element to the substrate, and a cavity between the first anchor and the second anchor and between the electrically movable heating element and the substrate.

First claim

What is claimed is:

1. A method for forming a micro electro-mechanical system (MEMS) heater element, the method comprising:
forming a dielectric layer over a substrate;
patterning the dielectric layer to form a cavity within the dielectric layer;
forming a sacrificial layer in the cavity;
depositing a first insulating layer over the sacrificial layer;
depositing a resistive conductor layer over the first insulating layer;
patterning the resistive conductor layer to form a heater element that overlies the cavity and extends to two regions of the dielectric layer; and
removing the sacrificial layer from the cavity so that a portion of the heater element is spaced from the substrate.

2. The method of claim 1 , further comprising forming a first contact at a first end of the resistive conductor layer and a second contact at a second end of the resistive conductor layer.

3. The method of claim 1 , further comprising depositing a second insulating layer over the resistive conductor layer to encapsulate the heater element.

4. The method of claim 3 , wherein a thickness of the second insulator layer is between 0.1 and 0.5 of a thickness of the heater element.

5. The method of claim 3 , wherein the first insulating layer and the second insulating layer comprise silicon nitride.

6. The method of claim 5 , wherein the first insulating layer and the second insulating layer comprise a material with high tensile strength.

7. The method of claim 1 , further comprising forming an array of stiction bumps at a surface of the first insulating layer.

8. The method of claim 1 , wherein the heater element is configured to be heated by causing a current to flow through the heater element when the portion of the heater element is spaced from the substrate.

9. The method of claim 8 , wherein the heater element is further configured to be cooled by causing the portion of the heater element to contact the substrate while being electrically isolated from the substrate.

10. A micro electro-mechanical system (MEMS) device comprising:
a substrate;
a dielectric layer disposed over the substrate;
a cavity formed in the dielectric layer; and
a heater element overlying the cavity and extending to two regions of the dielectric layer, the heater element comprising a first insulating layer and a resistive conductive layer disposed over the first insulating layer.

11. The MEMS device of claim 10 , further wherein the heater element further comprises a second insulating layer disposed over the resistive conductive layer to encapsulate the heater element.

12. The MEMS device of claim 11 , wherein a thickness of the second insulator layer is between 0.1 and 0.5 of a thickness of the heater element.

13. The MEMS device of claim 11 , the first insulator layer and the second insulator layer comprise silicon nitride.

14. The MEMS device of claim 13 , wherein the first insulator layer and the second insulator layer comprise a material with high tensile strength.

15. The MEMS device of claim 10 , further comprising an array of stiction bumps disposed at a surface of the first insulator layer.

16. The MEMS device of claim 10 , wherein the heater element spaced from the substrate is configured to be heated by causing a current to flow through the heater element when a portion of the heater element overlies the cavity and is spaced from the substrate.

17. The MEMS device of claim 16 , wherein the heater element is further configured to be cooled by causing the portion of the heater element contacts the substrate while being electrically isolated from the substrate.

18. A method for forming a micro electro-mechanical system (MEMS) heater element, the method comprising:
forming a cavity with a region of material;
forming a movable membrane anchored to the region of material and overlying the cavity, the movable membrane including an electrically movable heating element;
forming a first piezo material physically attached the movable membrane at a first portion of the region of material; and
forming a second piezo material physically attached the movable membrane at a second portion of the region of material, wherein the first and second piezo materials are configured to cause the movable membrane to move between a first position at a top of the cavity to a second position within the cavity.

19. The method of claim 18 , wherein the heating element comprises a serpentine structure overlying the membrane.

20. The method of claim 18 , further comprising forming a heat spreader structure in the same layer as the heating element, the heat spreader structure being electrically insulated from the heating element.

Assignees

• Infineon Technologies Ag

Inventors

• Glacer Christoph

Classifications

• G01N2021/1704

  in gases · CPC title

• G01J5/061

  by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats · CPC title

• G01J2005/063

  Heating; Thermostating · CPC title

• G01J5/0245

  for performing thermal shunt · CPC title

• G01J3/108

  for measurement in the infrared range · CPC title