High-Resolution Digital Holography for MEMS Process Monitoring and Device Testing

Principal investigator: Ms Xu Lei

Co-investigator:As/Prof Miao Jianmin, A/Prof Anand Asundi


Date started: 01/1999

Date completed:


To study digital holography and improve the measurement resolution. To explore the interferometric applications in MEMS process monitoring and device testing.


Current development of MEMS engineering place unprecedented requirements on the materials and designs. To ensure optimum process parameters, the reliability and functionality of the MEMS devices, many research efforts focus on measurement and testing technologies. Digital holography is a novel technology with great potential in the non-destructive measurement. Its successful applications depend on good adaptation to microscopic techniques to handle the challenges of small size and the unique surface optical properties of the microstructures. At the same time, improvement of measurement performance is urgently required to meet the needs of high accuracy and resolution.

In-line Digital Micro-Holo-Interferometry

In this project, In-line digital micro-holo-interferometry (IDMHI) is proposed. Figure 1 shows the schematic design of the system.

Figure 1. Schematic design of IDMHI system

System Mechanism & Interferometric Application

Figure 2 demonstrates the experimental application of IDMHI on displacement analysis of a micro cantilever beam. The displacement field is measured with a resolution of about 1nm. The experimental results on the load-induced deflection are used as accurate input data for further analysis of the microstructures.

pic 2
Figure 2. Experimental application on displacement analysis of micro cantilever beam.


Last updated: 20.10.99