Emerging piezoMEMS apps and ion beam etch solutions for next gen MEMS and sensors

Yole Developpement of France recently organized a seminar on next generation MEMS. The speakers were Dr. Eric Mounier, project manager, Yole Développement, and Dr. Adrian Devasahayam, senior director, Technology, Veeco Instruments.

As performance requirements for MEMS and other devices become more stringent, the industry is encountering etch challenges that cannot be overcome with existing toolsets. The use of materials that are not readily etched reactively, combined with higher sensitivities to post etch corrosion in smaller devices, is driving a search for a more suitable etch solution for certain applications.

According to Dr. Mounier, Yole, it is estimated that until 2015, the ferroelectric thin film business will grow at rate of +7.5 percent per year with many current or new applications. In the MEMS field, these applications could be wafer level autofocus, IR sensors, RF switches, medical ultrasonic transducers. In other markets, applications would include IPD tunable capacitor, IPD hearing aids, FeRAM, optical switches, etc.MEMS ferroelectric thin films: Source: Yole.

Dr. Mounier added that the ferroelectric thin films global market growth is mainly driven by two high growth rate MEMS applications until 2015, namely, IR sensors and wafer level optic autofocus.

He added that many other applications are expected to emerge in 2014-2015. These would include RFMEMS and ultrasonic thin film technologies that are under development by large groups, such as IBM, Philips, Toshiba, etc. IPD high density planar capacitors with thin films are being evaluated all over the world by key companies, such as STMicroelectronics, Ipdia, On Semi, Maxim, etc.

Magnetometers using MEMS technologies are currently under development, such as at Bosch, VTT, etc.. They are likely to be integrated with accelerometers to create inertial sensing modules (combo sensors) for consumer/auto applications.

Dr. Adrian Devasahayam, Veeco, advised that Veeco has a broad portfolio of process technologies for various applications. Ion beam etch is a key technology for several applications, which use hard to etch materials. Veeco has developed IBE processes for several key areas, such as PZT etch, magnetic sensor materials, III-V materials, metal etch for ohmic materials and hard mask materials.

New uniformity, CD and damage requirements for emerging applications has been driving ion beam etch activity. A high uniformity across large areas, accurate end-point detection and etch profile shape control has been a common request.