**4.4 Micro-resonator measurement**

102 Microelectromechanical Systems and Devices

Experiments were done on a micro pressure sensor using PSI under the air condition. From figure 15(a), a deformed membrane can be seen to show the air pressure. The deform value shows the change of the pressure. From figure 15(b), the height difference between the highest position and the lowest position is 1345.7 nm, which is matched with the designed

(a) 3D display (b) profile

Combining with Otsu method from image segmentation technique, we measured a film thickness standard in WLI measurement (centre average thickness: 1052.2 nm±0.9 nm, refraction index: 1.46, model number: FTS4-10100, VLSI) which was calibrated by an ellipsometer in 632.8 nm wavelength. The system equipped 10× Mirau objective to perform a set of repeated measurements". The thickness and the surface topography were successfully extracted, which were shown in table 2 and figure 16. The *Ra* values of the

(a) 3D structure (b) Profile

**4.2 Micro pressure sensor measurement** 

Fig. 15. Results of micro pressure sensor measurement

Fig. 16. Film thickness standard measurement

upper and lower surfaces were 7.30 nm and 7.32 nm, respectively.

**4.3 Film structure measurement** 

value.

With WLPSI, a micro resonator manufactured by Microelectronics Center of North Carolina (MCNC) was measured. With a 20× Mirau objective, the micro resonator was illuminated by a white light illuminator (central wavelength is 600 nm), the scanning range was configured to be 9 μm and the scanning step was 45 nm. The result is shown in figure 17. The height of the comb-finger profile is approximately 3.8 μm.

#### (a) 3D structure of the resonator (b) Comb-finger profile of the resonator
