MEMS Device Comprising a Hermetically Sealed Cavity and Devices Obtained Thereof

• US 20120013020A1
• Filed: 07/13/2011
• Published: 01/19/2012
• Est. Priority Date: 07/15/2010
• Status: Abandoned Application

• Current Assignee: IMEC International
• Original Assignee: IMEC International
• Inventors: Guo, Bin, Haspeslagh, Luc
• Application Number:
  US13/181,833
• Publication Number:
  US 20120013020A1
• Time in Patent Office: Days
• US Class Current: 257/774
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81C 1/00277 for maintaining a controlled atmosphere inside of the cavity containing the MEMS

Abstract

A MEMS device is disclosed comprising a cavity containing a MEMS component, the cavity being formed in a dielectric layer stack having a thickness t_d, whereby the cavity and the dielectric layer stack are sandwiched between a substrate and a sealing dielectric layer having a thickness t_s, and whereby the MEMS component is enclosed by at least one trench extending over the thickness t_d of the dielectric layer stack and of the sealing dielectric t_s.

Claims

1. A method for manufacturing a MEMS device comprising a hermetically sealed cavity containing a MEMS component, the method comprising:

providing a substrate having, on a major surface, a stack of a structural layer on a first dielectric layer;

patterning the structural layer to form a MEMS component;

forming a second dielectric layer overlying the MEMS component;

forming a sealing dielectric layer overlying the second dielectric layer;

forming, in the stack of dielectric layers, a trench enclosing the MEMS component thereby extending to the substrate;

depositing a membrane layer overlying the sealing layer thereby filling the trench; and

patterning the membrane layer thereby forming a membrane at the location of the cavity and an electrode covering the filled trench.

2. The method of claim 1, further comprising removing the first and second dielectrics selective to the sealing dielectric layer, thereby forming the cavity which contains the MEMS component.

3. The method of claim 2, further comprising forming openings through the membrane and the sealing dielectric layer at the location of the MEMS component, through which openings the first and second dielectrics are removed.

4. The method of claim 3, further comprising closing the openings in the membrane after the selective removal of the first and second dielectric.

5. The method of claim 1, wherein the sealing dielectric is selected from the group consisting of silicon-carbides and alumina-oxides, and wherein the first and second dielectrics are silicon-oxide.

6. The method of claim 1, wherein the membrane layer is a silicon-germanium layer.

7. The method of claim 1, wherein the substrate is a Semiconductor-On-Insulator (SOI) substrate and the semiconductor layer thereof is the structural layer.

8. A MEMS device comprising:

a dielectric layer stack having a thickness; and

a hermetically sealed cavity containing a MEMS component and formed in the dielectric layer stack, wherein the hermetically sealed cavity and the dielectric layer are sandwiched between a substrate and a sealing dielectric layer, and wherein the MEMS component is enclosed by a trench extending over the thickness of the dielectric layer stack.

9. The MEMS device of claim 8, wherein the sealing dielectric is selected from the group consisting of silicon-carbides and alumina-oxides, and wherein the dielectric layer stack comprises silicon-oxide.

10. The MEMS device of claim 8, further comprising a membrane covering the sealing layer at the location of the cavity and an electrode covering and filling the trench.

11. The MEMS device of claim 10, wherein the membrane and electrode are formed in the same material

12. The MEMS device of claim 11, wherein the same material is silicon-germanium.

13. The MEMS device of claim 9, further comprising a membrane covering the sealing layer at the location of the cavity and an electrode covering and filling the trench.