Modular Monolithic Microelectromechanical (MEMS) System Technology (M3S)
Abstract
Surface micromachining with monolithic integrated electronic evaluation circuits is an attractive technology for low-cost, highly compact sensors. Unfortunately, past monolithic sensor/circuits processes suffer from technology complexity resulting from the combination of two complex fabrication processes. The complex interactions slow down progress and preclude a straightforward upgrade path when a better circuit process becomes available. The technology developed here overcomes the disadvantages. By fabricating the mechanical structures first and embedding them in a planarized wafer, it achieves a high degree of separation between the two processes. In fact, the mechanical structures are fabricated by Analog Devices, while a CMOS foundry adds electronic circuits. New circuit options are added by simply sending the wafers to a different foundry. A full complement of gyroscopes and accelerometers fabricated in the modular process demonstrates the practicality Of the approach. Compared to conventional processes, the sensors benefit from unproved circuits performance and higher integration capability. A 5-V only gyroscope operating at ambient pressure underscores the flexibility of the approach to implement functions that normally require special technologies, such as high voltage transistors or vacuum packaging. The simpler approach greatly reduces cost and should be of value particularly in cost-sensitive applications such as smart ammunition or micro-air-vehicles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2002
- Accession Number
- ADA409761
Entities
People
- Bernhard E. Boser
- John Yasaitis
Organizations
- University of California, Berkeley