Component including two semiconductor elements between which at least two hermetically tightly sealed cavities having different internal pressures are formed and method for manufacturing such a component

• US 20150353346A1
• Filed: 06/04/2015
• Published: 12/10/2015
• Est. Priority Date: 06/06/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: HEUCK, Friedjof, Tebje, Lars, Stahl, Heiko, Neul, Reinhard, Gonska, Jullian
• Granted Patent: US 9,428,378 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81B 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence
• CPC Class Codes: B81C 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 23/02 Containers; Seals H01L23/12, H01L23/34, H01L23/48, H01L23/552, H01L23/66 take precedence; for memories G11C
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container

Abstract

For the targeted influencing of the internal pressure within a cavity between two elements of a component, a getter material or an outgassing material is situated in an additional cavity between the two elements. After the two elements are bonded to one another, the additional cavity is still to be joined via a connecting opening to the cavity. The getter material or the outgassing material is then activated so that gasses are bound in the additional cavity and in the connected cavity, or an outgassing takes place. Only when the sought internal pressure has established itself in the connected cavity is the connecting opening to the additional cavity closed. In this way, the getter material or the outgassing material is only used for establishing a defined internal pressure, but no longer has any influence on the internal pressure within the cavity during ongoing operation of the component.

Claims

1. A component comprising:

at least two semiconductor elements connected to one another via at least one structured connecting layer;

wherein at least two hermetically tightly sealed cavities are formed between the at least two semiconductor elements, and different defined internal pressures prevail in the at least two hermetically tightly sealed cavities, and wherein at least a first one of the cavities is sealed by a circumferential bonding frame in the connecting layer, and wherein at least a second one of the cavities is at least partially sealed by a welding joint between the at least two semiconductor elements.

2. The component as recited in claim 1, wherein a semiconductor material of at least one of the two semiconductor elements is included in the welding joint.

3. The component as recited in claim 2, wherein a metallic coating of least one of the two semiconductor elements is involved in the welding joint.

4. The component as recited in claim 2, wherein the welding joint closes a connecting opening to an additional, hermetically tightly sealed cavity between the two semiconductor elements, and one of a getter material or an outgassing material is situated in the additional, hermetically tightly sealed cavity.

5. A method for manufacturing a component having at least two semiconductor elements connected to one another in such a way that at least two hermetically tightly sealed cavities are formed between the two semiconductor elements, in which cavities different defined internal pressures prevail, the method comprising:

providing at least one of the two surfaces of the two semiconductor elements to be joined with at least one structured connecting layer; and

subsequently establishing a bond connection between the two semiconductor elements via the structured connecting layer, wherein at least one of the two cavities is hermetically tightly sealed at a predefined ambient pressure;

providing at least one additional cavity;

providing at least one of the two surfaces of the two semiconductor elements to be joined with one of a getter material or an outgassing material in the area of the additional cavity;

structuring at least the connecting layer in such a way that at least one connecting opening as a pressure connection is provided between the additional cavity and at least one connected cavity after the establishing of the bond connection;

activating the one of the getter material or the outgassing material after establishing the bond connection so that gasses in the additional cavity and the connected cavity are bound or an outgassing takes place; and

closing the connecting opening when the sought internal pressure has been established in the at least one connected cavity.

6. The method as recited in claim 5, wherein the connecting opening is closed in a laser welding process with the aid of an infrared laser.

7. The method as recited in claim 6, wherein a hermetically tight welding joint is established in the laser welding process between the semiconductor materials of the two element surfaces to be joined by melting the semiconductor materials of the two element surfaces.

8. The method as recited in claim 5, wherein:

an eutectic bond connection is established between the two semiconductor elements by;

(i) applying and structuring at least one bonding layer on both of the two element surfaces to be joined; and

(ii) a hermetically tightly sealed welding connection between the semiconductor material of the one element surface to be joined and the bond material on the other element surface is established during the laser welding process.

9. The method as recited in claim 5, wherein at least one of the two surfaces of the two semiconductor elements to be joined is structured in order to produce recesses for at least one of (i) the at least two cavities and (ii) the at least one additional cavity.

10. The method as recited in claim 5, wherein:

the two semiconductor elements are each produced in a wafer composite;

the bonding connection between the two semiconductor elements is established in the wafer composite;

the subsequent closure of the connecting opening takes place in the wafer composite; and

the at least one additional cavity is situated in the border area of the component so that the at least one cavity is separated when separating the component.