MEMS pioneer with a strong technological legacy

When I joined Bosch R&D, we were exploring plasma etching processes for a wide range of applications and materials. Different materials required different process conditions, and we often encountered unexpected effects. For example, certain dielectric materials would stop etching altogether and instead form layers on the wafer surface.

At the same time, we were upgrading a prototype etching tool to enable better control of plasma conditions. This gave us the opportunity to separately optimize plasma density and ion energy, which turned out to be crucial for achieving the desired etching performance.

Looking back, the Bosch Process was not the result of a single breakthrough moment. It emerged from combining practical process experience, advances in equipment capabilities, and a team willing to experiment and push boundaries. What I remember most is the optimism and determination within the team. We were convinced that there had to be a solution, and this mindset ultimately enabled the development of what is now well-known as the Bosch Process.

The evolution of MEMS has never been driven by isolated breakthroughs. It has always been the result of close interaction between product innovation, process technology, and manufacturing capabilities.

One of the first major milestones was the introduction of MEMS-based acceleration sensors for automotive airbags. As these products entered production, new technological challenges emerged, leading to continuous advances in both processes and equipment.

A second key step was the development of MEMS gyroscopes for electronic stability control systems. Once again, overcoming technical limitations drove further innovation and significantly expanded the role of MEMS in automotive applications.

Around twenty years ago, MEMS entered consumer electronics on a large scale. This dramatically increased both the variety and the volume of MEMS products, transforming the industry and accelerating innovation worldwide.

From my perspective, three developments stand out in particular:

• MEMS technology helped make automotive safety systems affordable and accessible across all vehicle segments.
• The widespread adoption of gyroscopes after the famous “moose test” in the late 1990s fueled major growth in automotive MEMS.
• The expansion into consumer electronics created an entirely new level of scale and application diversity for MEMS technology.

Even today, every new product generation, application field, or wafer size transition introduces new challenges that require engineering creativity. This continuous evolution is what makes MEMS such a fascinating field.

What has kept me motivated is simple: MEMS technology never stands still.

Throughout my career, every new product, application, or manufacturing challenge brought something new to learn and new challenges to solve. The field combines physics, engineering, manufacturing, and innovation in a unique way. It is this constant variety that has kept it exciting for more than three decades. And I am convinced it will remain just as fascinating in the years ahead.

To me, MEMS technology resembles a large mosaic. Each technology element, product generation, and application adds another piece to the picture. What makes it special to this day is that the mosaic is constantly growing. New applications create new requirements, which in turn reveal new physical effects and new opportunities for innovation. There is always another challenge to solve and another piece to add. I have never stopped being fascinated by the continuous discovery process.

What makes me proud is seeing how MEMS technology has improved everyday life in so many different ways.

First, MEMS helped make advanced automotive safety systems affordable, contributing to the protection of millions of people around the world. Second, MEMS sensors have become an essential part of consumer devices such as smartphones, where they enable countless functions that many of us now take for granted.

And finally, I am proud that this technology has created opportunities for generations of engineers and specialists. Seeing so many talented people working in such a dynamic and innovative field is incredibly rewarding.

Several trends will significantly influence the future of MEMS. One of them is the continued increase in aspect ratios, driven by the need for higher performance and smaller sensor footprints. As structures become narrower and deeper, new physical effects will emerge that require innovative engineering solutions.

Another trend is the growing demand for applications involving very large etched areas. Achieving the necessary throughput and uniformity will require further advances in manufacturing equipment and potentially new etching approaches.

The industry's transition toward 300 mm wafer manufacturing will also remain a major focus. Moving from 200 mm to 300 mm is far more than a simple transfer and requires substantial development work in both processes and equipment.

Sustainability will be another key driver. The search for alternatives to PFAS-related process gases with lower global warming potential while simultaneously maintaining the high performance standards required for MEMS production is becoming increasingly important.

Finally, close collaboration with equipment suppliers will become even more critical. MEMS performance depends heavily on manufacturing equipment, and many future innovations will only be possible through strong partnerships between device manufacturers and tool providers.

Collaboration has always been fundamental to MEMS innovation. Successful product development requires experts from many different fields to work closely together from the very beginning. A shared understanding of product requirements, technical challenges, manufacturing needs, and customer expectations helps avoid costly detours and accelerates progress.

In my experience, this interdisciplinary collaboration creates a continuous learning cycle that enables faster development and smoother transitions into production. It is one of the key reasons for Bosch's long-term success in MEMS.

Keep solutions as simple as possible! Engineers are often tempted to overengineer, but simplicity is one of the keys to successful and scalable products. At the same time, it is important to think beyond the immediate problem and consider the broader consequences of technical decisions. Hence, the best solutions are those that not only solve today's challenge but also work well within the larger system and remain practical for manufacturing.

I would tell myself to think even more boldly and further outside the box. Fortunately, together with experienced colleagues and supportive management, we moved in the right direction quickly and successfully. Looking back, the willingness to challenge established thinking was one of the most important ingredients in turning an idea into a technology that continues to shape the MEMS industry today.