New World Record in High-Aspect Ratio Microstructure Measurement!

A new record has been achieved for the aspect ratio measurement of micro structures.

Working in conjunction with a major equipment manufacturer, Prof. Lars Mattsson, leader of the Metrology Division of the 4M Network of Excellence, reports that a new aspect ratio of 50:1 was recently achieved in laboratory measurements following the optimisation of an existing optical metrology system.

Prof. Mattsson, who is Chair of Industrial Metrology and Optics at KTH, Stockholm in Sweden, has benefitted from his membership of the 4M Network to visit other laboratories and audit their metrology facilities, comparing the performance of various systems using X-ray lithography manufactured artefacts made within the Network’s own Polymer Division.

“There are currently no suitable standards in high aspect ratio micro-metrology, and it is an issue that will impact on many of the growth areas in micro-manufacturing” said Mattsson. ”Different equipment developed by a variety of companies and being used by operators in a number of ways inevitably leads to uncertainty in the measurements provided. And strangely enough the worst measurement errors were discovered in the horizontal x-y plane at the top of deep microstructures. This was a complete surprise for the instrument manufacturers as well.”

“In 4M I have been able to observe different equipment being operated in different environments on standard test pieces. This has enabled me to establish the measurement limitations of today’s equipment, and take this information to metrology equipment manufacturers as useful information for future instrument development.”

This has recently lead to Prof. Mattsson working with one major equipment manufacturer and, in collaboration with them, improving the performance of their optical measurement system such that it was able to achieve measurements of a star shaped microstructure with an aspect ratio of 50:1, the actual dimensions being 400 µm : 8 µm.

The 4M Network of Excellence will soon become the 4M Association, with membership open to all.