Long-term Stability of VAcuum-encapsulated MEMS Devices using Eutectic Wafer BONDing

Información del proyecto

VABOND

Identificador del acuerdo de subvención: IST-2001-34224

Proyecto cerrado

Fecha de inicio 1 Abril 2002

Fecha de finalización 31 Marzo 2005

Financiado con arreglo a

• Programme for research, technological development and demonstration on a "User-friendly information society, 1998-2002"

Coste total

€ 4 563 942,00

Aportación de la UE

€ 2 399 986,00

Coordinado por

FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Germany

Objetivo

The proposed project aims at the development of improved wafer-to-wafer bonding techniques which allow long-term vacuum encapsulation especially for those micro-electro-mechanical systems (MEMS) requiring high-vacuum cavities to ensure a good performance and to improve the life expectancy and reliability. The vacuum wafer bonding will be optimised using eutecting bonding in combination with getter materials inside the device cavity. Furthermore, a hermetic feed through technology will be developed enabling vertical electrical visa through the cap wafer.

In the technology integration and validation phase the new technologies for high-vacuum encapsulation of MEMS devices will be applied to industrial demonstrators:
- RF-switch and HF resonator for telecommunication and consumer applications;
- Pressure sensor for high-reel avionics and industrial applications.

Objectives:
As many MEMS devices require a vacuum or controlled atmosphere operation, the main objective of the proposed project is to provide a high-vacuum encapsulation technology for MEMS devices working on wafer-level. The detailed objectives are:
- develop a vacuum wafer bonding technology using eutectic bonding in combination with getter materials inside the cavities enabling a stable vacuum (10-4 mbar, 10 years)
- develop a getter technology covering materials and processes which is compatible to Si-based MEMS technology;
- provide industrial processes and equipment for the vacuum wafer bonding in combination with getters;
- develop a vertical feed through technology enabling low stress, high density interconnect performance and excellent RF properties;
- develop in-situ measurement techniques for the internal pressure for the high-vacuum and the low-vacuum range, as well as for in-situ moisture detection;
- reliable demonstrators employing the new high-vacuum encapsulation technology.

Work description:
The project starts with a concept phase in which the technology specifications as well as the specifications of the demonstrators are compiled and agreed.
Then passive test structures are designed and realized which are needed for the subsequent process developments of the technologies for wafer-level, high-vacuum encapsulation of MEMS: eutectic wafer bonding; getter deposition, structuring and activation; electrical feed throughs realized as vertical vias through the cap wafer.
In the next step the characterization of the single technologies and of the test assemblies as well as the reliability analysis is performed.
Therefore, in-situ measurement techniques for measuring the internal pressure and moisture content in the device cavity are evaluated, the corresponding test structures are designed and realized. The vacuum-bonded test structures are used for in-situ measurements to characterize the test assemblies and analyse the long term stability of the internal pressure, humidity and other reliability relevant parameters related to the cavity atmosphere.
In the next workpackage (technology integration and validation) the technologies for high-vacuum encapsulation of MEMS devices are applied to the previously defined and specified demonstrators. Demonstrator assemblies are realized and tested according to the systems specifications.
Finally, dissemination and exploitation of the results from the project are performed.

Milestones:
The final result: the demonstrators realized using the new vacuum encapsulation technology and tested against the specifications. Important milestones on that way are:
- eutectic wafer bonding is hermetically tight according to MIL-STD-883D
- selection of getter materials and getter patterning technique;
- vertical electrical feed through processed on wafer-level are hermetically tight and work electrically and mechanically (stress).

Ámbito científico (EuroSciVoc)

• ingeniería y tecnología › ingeniería eléctrica, ingeniería electrónica, ingeniería de la información › ingeniería electrónica › sensores

Programa(s)

• FP5-IST - Programme for research, technological development and demonstration on a "User-friendly information society, 1998-2002"

Tema(s)

• 2001-4.7.2 - Microsystems

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.

• Aportación de la UE: Sin datos
• Dirección: HANSASTRASSE 27C ; 80686 MUENCHEN ; Alemania
• Coste total: Sin datos

Participantes (5)

E V GROUP E. THALLNER GMBH

Austria

• Aportación de la UE: Sin datos
• Dirección: GEWERBEGEBIET ; 4780 ST. FLORIAN
• Coste total: Sin datos

SAES GETTERS S.P.A.

Italia

• Aportación de la UE: Sin datos
• Dirección: VIALE ITALIA 77 ; 20151 LAINATE (MI)
• Coste total: Sin datos

STMICROELECTRONICS S.R.L.

Italia

• Aportación de la UE: Sin datos
• Dirección: VIA OLIVETTI 2 ; 20041 AGRATE BRIANZA
• Coste total: Sin datos

THALES AVIONICS SA

Francia

• Aportación de la UE: Sin datos
• Dirección: 1 AVENUE CARNOT ; 91883 MASSY
• Coste total: Sin datos

UNIVERSITA DEGLI STUDI DI PAVIA

Italia

• Aportación de la UE: Sin datos
• Dirección: STRADA NUOVA 65 ; 27100 PAVIA
• Coste total: Sin datos