On-wafer device characterization for today’s complex chips

Increasingly complex ultra-high frequency IC chips demand state-of-the-art RF characterization, and Philips Engineering Solutions offers on-wafer device characterization with powerful functionality. Mark de Haas, Electronic Measurement Coordinator, and customer Alfons Groenland, Research Scientist Micro Systems and Devices, Philips Research, share their insights.

“Today’s wafer-based devices can accommodate a stunning number of structures on a tiny surface,” Mark explains. “Structures on wafers are becoming increasingly complex, incorporating, for example, movable membranes, light sources or fluids that provide specific functions. Measurements require dedicated software and equipment that can rapidly move over tiny surfaces and take multiple measurements. This requires new methods, for example using microwave, high-speed high-precision cameras, laser interference or thermal measurements.”

Online access to test results from a remote location

“Originally, our infrastructure was aimed at microwave technology at wafer level. Later, we added IV and CV technology for electrical current and capacitance characterization. Our four-port Microwave PNA network analyzer enables on-wafer characterization up to 67 GHz, ultra- low-level CV and IV measurements, and multi-purpose probing. An important part of what we do is a helping define tests and analyzing test results. We’ve carried out a wide variety of large projects. For example, we can create a ‘virtual lab’ for remote access to the tests. Distant customers have online access to equipment and interfaces and can observe and manipulate measurements and results.”

“At Philips Research, we have a large number of technical capabilities in-house, and this allows us to come up with complex multi-disciplinary innovative products that require multi-disciplinary development teams,” explains Alfons Groenland, Research Scientist Micro Systems and Devices.

“However, generally, there are no standard test methods available for these novel components. We enjoy working in close cooperation with Mark de Haas and his team and creating new test methods. We simply couldn’t do this type of measurement as quickly, easily, flexibly and accurately anywhere else. A huge advantage of working together is the fact that we can easily run new tests every time we make any alterations to our components. This avoids delays which could add up to many weeks.”

Photo: Mark de Haas, Electronic Measurement Coordinator in the Electronic Measurement Lab

RF Probe Station: new functionality

New independent motor controlled probes allow free coordinate setting, making them ideal for use with irregularly formed or fragile devices.

“In the semiconductor industry, we’re used to carrying out automatic measurements in square arrangements with a number of fixed electrical probes. One example of a process we designed with Philips Engineering Solutions is a sophisticated set of measurement probes that can take measurements in different configurations across the wafer surface. It allows the semi-automatic measurement of devices on a wafer that are arranged in, for instance, circular patterns. These ‘Flying Probes’ can be guided across larger distances as well as over a few microns and take highly accurate measurements at extremely low electrical levels, even when contact points are diametrically opposed. The probe does this without applying excess pressure, which can destroy the substrate,” says Alfons Groenland.

“Besides offering facilities, consulting and test design and analysis support, Philips Engineering Solutions also helps us live up to the highest external standards. Testing our ultrasound equipment for medical applications has to be carried out to ISO 13485 specifications, for example. Philips Engineering Solutions measurements are fully logged, so these requirements are covered perfectly.”