HYBRID INTEGRATED COMPONENT AND METHOD FOR THE MANUFACTURE THEREOF

• US 20130334626A1
• Filed: 06/11/2013
• Published: 12/19/2013
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: WEBER, Heribert
• Granted Patent: US 8,823,116 B2
• Time in Patent Office: Days
• US Class Current: 257/416
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 1/00246 Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/0735 Post-CMOS, i.e. forming the micromechanical structure after the CMOS circuit
• CPC Class Codes: B81C 2203/0771 Stacking the electronic processing unit and the micromechanical structure
• CPC Class Codes: H01L 2224/11 Manufacturing methods
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005

Abstract

A hybrid integrated component includes: at least one ASIC element having integrated circuit elements and a back-end stack; an MEMS element having a micromechanical structure, which extends over the entire thickness of the MEMS substrate; and a cap wafer. The hybrid integrated component is provided with an additional micromechanical function. The MEMS element is mounted on the ASIC element, so that a gap exists between the micromechanical structure and the back-end stack of the ASIC element. The cap wafer is mounted above the micromechanical structure of the MEMS element. A pressure-sensitive diaphragm structure having at least one deflectable electrode of a capacitor system is implemented in the back-end stack of the ASIC element, which diaphragm structure spans a pressure connection in the rear side of the ASIC element.

Claims

1. A hybrid integrated component, comprising:

an ASIC element having integrated circuit elements and a back-end stack;

an MEMS element having a substrate and a micromechanical structure which extends over the entire thickness of the substrate of the MEMS element; and

a cap wafer;

wherein the MEMS element is mounted on the ASIC element in such a way that a gap exists between the micromechanical structure and the back-end stack of the ASIC element, and the cap wafer is mounted above the micromechanical structure of the MEMS element, and wherein a pressure-sensitive diaphragm structure having at least one deflectable electrode of a capacitor system is implemented in the back-end stack of the ASIC element, and the diaphragm structure spans a pressure connection in the rear side of the ASIC element.

2. The component as recited in claim 1, wherein the diaphragm structure having the deflectable electrode is implemented in at least one metallization level of the back-end stack.

3. The component as recited in claim 2, wherein the diaphragm structure has a layered structure, which includes multiple metallization levels and insulating layers.

4. The component as recited in claim 3, wherein two outer layers of the diaphragm structure are each metallization levels of the back-end stack.

5. The component as recited in claim 3, wherein a middle area of the diaphragm structure is stiffened by having a greater thickness than an edge area of the diaphragm structure.

6. The component as recited in claim 3, wherein:

the diaphragm structure includes a pressure-sensitive diaphragm element and at least one electrode element;

an edge area of the pressure-sensitive diaphragm element is incorporated in the layered structure of the back-end stack; and

the electrode element is only connected at selected points via at least one through contact to the pressure-sensitive diaphragm element, and the electrode element is otherwise not connected to the layered structure of the back-end stack.

7. The component as recited in claim 3, wherein at least one stationary counter element is implemented as a carrier for at least one stationary counter electrode of the capacitor system in the micromechanical structure of the MEMS element.

8. The component as recited in claim 7, wherein the micromechanical structure of the MEMS element includes at least one structural element for a pressure-independent sensor or actuator function.

9. The component as recited in claim 3, wherein the MEMS element is mounted via a standoff structure on the ASIC element, and the standoff structure is implemented in the form of at least one structured layer on at least one of the MEMS substrate and the ASIC substrate.

10. The component as recited in claim 9, wherein the cap wafer is mounted on one of the MEMS element or the ASIC element.

11. The component as recited in claim 3, wherein the component is one of a capacitive microphone, a loudspeaker, a pressure sensor, or a pressure switch component.

12. A method for manufacturing a hybrid integrated component, comprising:

integrating circuit elements into an ASIC substrate;

producing a back-end stack on the ASIC substrate, wherein a diaphragm structure having at least one deflectable electrode is applied in the back-end stack, and wherein the diaphragm structure is exposed in the back-end stack;

mounting an MEMS substrate on the back-end stack of the ASIC substrate in such a way that a gap exists between the MEMS substrate and the back-end stack of the ASIC substrate;

structuring an entire thickness of the mounted MEMS substrate;

producing a pressure connection in the rear side of the ASIC substrate; and

mounting a cap wafer above the micromechanical structure of the MEMS substrate.

13. The method as recited in claim 12, wherein:

the diaphragm structure is applied in the back-end stack by depositing insulating layers and metallization levels of the back-end stack one on top of another, and subsequently structuring the deposited insulating layers and the metallization levels; and

the diaphragm structure is exposed by removing the material of the insulating layers in the diaphragm area via passage openings in the micromechanical structure of the MEMS substrate starting from the rear side of the ASIC substrate using an etching method, the metallization levels of the back-end stack functioning as a vertical etch stop and through contacts between individual metallization levels functioning as a lateral etch stop.