Novel Manufacturing Technologies for MEMS Devices – High Vacuum Bonding for Sensors and Imprint Lithography for Photonic Devices
Wafer level bonding is an enabling technology for cost effective MEMS devices and will continue to be in the future. The performance requirements for the wafer to wafer bonding processes continue to rise. These requirements include reduction in wafer area consumed by the sealing ring, reductions in process temperature, increases in throughput, improved alignment, electrically conductive vias for integration of CMOS and MEMS, improvements in hermeticity, as well as increased cavity vacuum levels post bond. When these forces are combined with the growth in MEMS for the Internet of Things the wafer bonding performance requirements will continue to increase. Post bond cavity vacuum is important for important for gyroscopes as it effects the power consumed by the device and low power consumption will be critical for battery powered devices that will predominate in the IOT. Also, IR (infrared) detectors such as microbolometers require high vacuum levels for optimum performance. In this presentation the basics of vacuum encapsulation by wafer bonding will be reviewed and then recent advances in high vacuum wafer bonding will be presented. These advances will enable a new generation of high performance sensors.
Nanoimprint Lithography (NIL) has for a long time been praised as the lithography technology of the future. After more than a decade of research in the area of NIL, the technology has reached a level of maturity that enables first applications to transition to high volume manufacturing (HVM) utilizing NIL. Those first applications utilizing NIL in high volume manufacturing are not found in the microelectronics manufacturing field which sticks more to conservative techniques. Instead, novel applications in nanotechnology, biotechnology and in particular photonics emerged during recent months as the first applications that are on a path to move NIL into high volume manufacturing. Unique capabilities as manufacturing a wide range of structure sizes and shapes, including 3D, and nanopatterning of high-topography (rough) surfaces are an essential criterion that are key enabling to support the needs of these technologies. As equipment and processes are closely linked to the performance photonic devices much progress has been enabled by new developments. This paper reviews the capabilities that NIL provides today and what applications are poised to benefit from those new capabilities. It will review on how NIL can be used for the manufacturing of low cost, high resolution structures for photonic applications. Building on that overview, NIL technologies are introduced that are tailored to the unique needs of photonic applications while providing lowest cost of ownership. Furthermore, application scenarios are presented, shedding light on how NIL is implemented in actual high volume manufacturing scenarios.