SCHOTT solutions no. 1/2011 > Machine Vision

The machine vision system that is being put to use in the BEANS Device Center was custom built specifically to check for defects in MEMS components. It allows for high-quality and yet relatively cost-effective inspection of the surfaces of wafers. Photo: Moritex/H.Murakami

Unlimited Possibilities


MORITEX, the company that belongs to SCHOTT Group, manufactures highly advanced inspection systems. One example is a machine vision inspection system, which allows for cutting edge research to be performed in the area of MEMS technology.


Yutaka SuzuKi & Takeshi Harada

MEMS, or Micro-Electro-Mechanical Systems, are used in all types of everyday devices, such as automobiles, mobile telephones and home game consoles. MEMS use a variety of micromachining technologies to place micron-scale parts on a single substrate. MEMS devices are tiny, highly precise, and offer superior energy-saving features. They make it possible to manufacture ultra-small actuators and many other types of sensors. They are key devices in next-generation manufacturing, with cooperative industry-university research proceeding as a national R & D project. The Japanese company MORITEX, a member of SCHOTT’s Lighting and Imaging Business Unit, uses its expertise in optics to manufacture and market a wide variety of specialized devices, including inspection equipment. One of these devices was selected by the BEANS G Device Center in Tsukuba that conducts MEMS research as a national R & D project: ”Our machine vision inspection system makes use of the fact that silicon transmits infrared light and can automatically check MEMS devices for defects. The unit we delivered to the BEANS G Device Center is customized to automatically perform surface inspection of a 200 mm wafer using visible light. If this equipment works out well, we anticipate a considerable up-tick in adoption of this machine vision inspection system in MEMS device manufacturing and by semiconductor makers,” says Junya Inoue, the sales representative in charge of the inspection system.
The BEANS G Device Center does research on further developing MEMS. An ­intelligent clean room that includes an 8-inch MEMS production line was ­completed in December 2010. Photo: Moritex/H.Murakami
The BEANS research center started as an industry-academic joint project launched by Japan’s Ministry of Economy, Trade and Industry. It is currently operated and managed by the New Energy and Industrial Technology Development Organization (NEDO). “BEANS” is an acronym for Bio Electromechanical Autonomous Nano Systems. The name reflects the expectation of the researchers who strive to establish integrated micro- and nano-technologies through a fusion of organic, inorganic, and bio materials. It is also a play on the Japanese phrase sangyo no kome, or ”the rice of industry,” which is used to mean the key or main product in a field. Just as semiconductors are considered to be the foundation of Japanese industry, this project hopes to grow MEMS as the next-generation ”beans of industry.” The MEMS production line at the BEANS G Device Center handles 8-inch wafers and is a fully integrated line that covers MEMS fabrication from front-end to back-end processing and testing. This large-scale facility also has 12-inch wafer processing equipment and is used for device prototyping to validate the success of the BEANS project. “We needed to check the variation in devices formed on 8-inch wafers. This normally calls for using extremely expensive wafer surface inspection equipment, but this machine vision inspection system allows us to cut costs significantly while maintaining a high level of quality. We plan to use the system to define the range of our evaluation,” said Takeshi Harada, General Manager of Research Department at the BEANS Laboratory. MEMS devices will play a major role in improving the living environment and help increase quality of life in the near future. MORITEX is working hard to establish its position as an inspection equipment maker in the field of MEMS research and manufacturing.
 

”We anticipate a considerable up-tick for machine vision inspection systems in the production of mems and semi-conductors.”

Junya Inoue · MORITEX Vertriebsmanager

 

8-Inch MEMS line benefits from an innovative automatic optical wafer inspection system

The BEANS project is an R & D project devoted to performing research into the micro- and nano-scale integrated manufacturing technology necessary to create the innovative devices of the future. The project started off as an enterprise consigned by NEDO (New Energy and Industrial Development Organization) in 2008. The goal is to develop three processes – processes that enable the fusion of bio and organic materials, processes for forming 3D nanostructures, and processes for continuous large-area manufacturing of micronano structures – but also to build related knowledge databases. The project has been run by the BEANS Research Center, a technology research cooperative, since 2009. Notable results include a robot with olfactory sensors, implantable blood sugar sensors, bile canaliculi fabrication technology, and thermoelectric material which have all been widely reported on in the media.
Takeshi Harada, General Manager of the Research Department at BEANS Laboratory, and his team perform research on advanced sensor network systems and environmentally friendly pro­cesses for manufacturing three-dimensional Photo: MORITEX/H. Murakami
In 2010, the BEANS project added a new R & D topic on the development of an advanced sensor network system and environmentally friendly processes, and launched G device@ BEANS. This new research initiative is aimed at developing a system with a smart clean room and advanced 8-inch MEMS production lines. The system will allow for a large number of high-performance MEMS sensor modules to be used in the clean room and MEMS production line for real-time monitoring of energy usage conditions, controlling of the air conditioning system, etc. With respect to low environmental impact processing, R & D work is being pursued on technologies such as the use of an alternative gas for deep etching of the silicon substrates used as MEMS materials and low temperature wafer-level packaging. Furthermore, their research encompasses constructing high-quality processes for the 8-inch MEMS production lines, accumulating process recipes compatible with new materials and new structures, improving the level of design technology for controlling process margins, and investigating process technology based on environmentally friendly, biocompatible polymers. In December 2010, a smart clean room and 8-inch MEMS prototype station were completed at the Research Center for Ubiquitous MEMS and Microengineering, housed in the research base of the independent administrative agency National Institute of Advanced Industrial Science and Technology (AIST) in Tsukuba East. This 8-inch MEMS line consists of two lines. The front-end processing line includes wafer cleaning, lithography, oxidation and diffusion, deposition, and etching. The back-end processing and testing line covers everything from chip and wafer-to-wafer bonding and wire bonding up to testing, including evaluations of the processed wafer profiles and the electrical properties of devices, etc. Together, these comprise a fully integrated 8/12-inch MEMS line. This line supports fine-pitch processing down to 0.35 µm line widths as well as three-dimensional micromachining, and is capable of processing everything from sensors and other time-tested MEMS devices to advanced devices.

The optical microscope automatic inspection system is based on the machine vision technology at Moritex. This system is used to automatically inspect the MEMS devices at wafer level, and evaluate yield and manufacturing variation. Being able to acquire such equipment in an order of magnitude lower in cost than semiconductor equipment was very attractive. The center is convinced that this unit will play a major role in inspection on its 8-inch MEMS line. <|