PSI - Issue 2_B

Toshiyuki Tsuchiya et al. / Procedia Structural Integrity 2 (2016) 1405–1412 Author name / Structural Integrity Procedia 00 (2016) 000 – 000

1408

4

45 ° tilt

Top view

One step Bosch Process

785nm

3 μm

1 μm

3 μm

Two step Bosch

151 nm

135 nm

2 μm

2 μm

500 nm

147nm

Oxide thinning

1 μm

3μm

3μm

Fig. 4. Fabricated silicon nanowire on bulk silicon substrate using three different approaches.

3. SOI-MEMS Tensile Testing Device with Integrated Silicon Nanowire

Silicon nanowires were integrated to an SOI-MEMS device for measuring the tensile properties, which was designed as a modification of a device developed for a fullerene nanowire testing by Tsuchiya et al. (2012). The schematic design of the device is shown in Fig.5. The device consists of a parallel plate capacitance for generating tensile force and a differential displacement sensor using parallel plate capacitance and suspending beams. The device structure was designed to adopt a silicon nanowire of 100 nm in diameter. The estimated force and displacement to test 5- μ m-long specimen were 30 μ N and 90 nm, respectively.

Specimen specification

Fixed

Diameter (nm) Length ( μm )

100

5 3

Parallel plate actuator

Fracture strength (GPa) Young’s modulus ( GPa) Required force ( μN ) Fracture displacement (nm)

168.9

30 90

Displacement sensor

Device specification

Force at 20 V( μN )

50

Displacement resolution (nm)

1

Suspending beams

SiNW

Force resolution ( μN )

0.12

Fig. 5 Schematic of SOI-MEMS tensile testing device. Dark blue regions are fixed to substrate and light blue regions are released and moving along tensile direction indicated with orange arrow. Target specification of nanowire specimen and device characteristics are listed in table.