Micro-electro-mechanical system (MEMS) structures and design structures

Patent metadata

Field	Value
Publication number	US-10549987-B2
Application number	US-201815916962-A
Country	US
Kind code	B2
Filing date	Mar 9, 2018
Priority date	Apr 12, 2013
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

Micro-Electro-Mechanical System (MEMS) structures, methods of manufacture and design structures are disclosed. The method includes forming a Micro-Electro-Mechanical System (MEMS) beam structure by venting both metal material and silicon material above and below the MEMS beam to form an upper cavity above the MEMS beam and a lower cavity structure below the MEMS beam.

First claim

What is claimed:

1. A method of forming a Micro-Electro-Mechanical System (MEMS) beam structure comprising:
forming metal material and semiconductor material on a substrate;
forming a MEMS beam above the metal material and the semiconductor material;
forming the metal material and the semiconductor material above the MEMS beam;
forming a lid over the metal material and the semiconductor material formed above the MEMS beam; and
venting, using an XeF 2 etchant, both the metal material and the semiconductor material above the MEMS beam and both the metal material and the semiconductor material below the MEMS beam to form an upper cavity structure above the MEMS beam and below the lid and to form a lower cavity structure below the MEMS beam and above the substrate,
wherein the metal material produces volatile fluorine when venting with the XeF 2 etchant.

2. The method of claim 1 , wherein the venting and thicknesses of the metal material and the semiconductor material above the MEMS beam are controlled to ensure that all or substantially all of the metal material above the MEMS beam is removed, prior to the removal of the semiconductor material above the MEMS beam.

3. The method of claim 1 , wherein the semiconductor material above and below the MEMS beam is one of silicon material and germanium material.

4. The method of claim 3 , wherein the semiconductor material above and below the MEMS beam is silicon material, and wherein forming the metal material and silicon material below the MEMS beam comprises forming the metal material on the substrate and forming the silicon material over the metal material.

5. The method of claim 4 , wherein forming the metal material and silicon material above the MEMS beam comprises forming the silicon material within a via in contact with the silicon material below the MEMS beam and forming the metal material over the silicon material.

6. The method of claim 5 , further comprising forming a vent hole in the lid to expose at least the silicon material above the MEMS beam.

7. The method of claim 6 , wherein at least one of the metal material above the MEMS beam and the metal material below the MEMS beam is formed by a physical vapor deposition process followed by a chemical vapor deposition process.

8. The method of claim 6 , further comprising forming an additional silicon material on the metal material above the MEMS beam.

9. The method of claim 8 , further comprising:
planarizing the additional silicon material;
forming the lid over the planarized additional silicon material;
forming at least one venting hole in the lid, exposing the additional silicon material; and
venting the metal material and the silicon material above the MEMS beam and the additional silicon material to form the upper cavity and the lower cavity.

10. The method of claim 1 , further comprising:
forming at least one vent hole in the lid and through the metal material formed above the MEMS beam to expose the semiconductor material above the MEMS beam; and
venting the semiconductor material above the MEMS beam while venting the metal material formed above the MEMS beam.

11. The method of claim 10 , wherein the lid is formed with a planar surface on an underside thereof by depositing the lid directly on one of the metal material over the MEMS beam or another layer of semiconductor material formed on the metal material over the MEMS beam.

12. The method of claim 10 , wherein the forming of the least one vent hole is forming at least two vent holes in the lid, wherein a first of the at least two vent holes exposes the semiconductor material above the MEMS beam and a second of the at least two vent holes exposes the metal material above the MEMS beam.

13. The method of claim 1 , wherein the metal material above the MEMS beam is formed in seams formed in the semiconductor material above the MEMS beam, and the venting begins with the semiconductor material above the MEMS beam.

14. The method of claim 1 , wherein the venting forms an undercut in at least one of the upper cavity and the lower cavity.

15. The method of claim 1 , wherein at least one of the metal material above the MEMS beam and the metal material below the MEMS beam is devoid of oxide.

16. The method of claim 1 , wherein the metal material is vented continually while the semiconductor material is being vented.

Assignees

• IBM

Inventors

• Brigham Michael T
• Jahnes Christopher V
• Luce Cameron E
• Maling Jeffrey C
• Murphy William J
• Stamper Anthony K
• White Eric J

Classifications

• B81C1/00047 Primary

  Cavities · CPC title

• B81C2201/0132

  Dry etching, i.e. plasma etching, barrel etching, reactive ion etching [RIE], sputter etching or ion milling · CPC title

• B81B2203/0315

  Cavities · CPC title

• B81C2201/0107

  Sacrificial metal · CPC title

• B81C1/00936

  Releasing the movable structure without liquid etchant · CPC title