Spin coating wafer fabrication process

The nano-antennas where fabricated on top of a 200 nm silicon dioxide layer on a standard silicon wafer. The substrate was spin coated with high resolution positive PMMA 950 K resist and electron beam lithography was used to define the nano-antenna structures. After exposure, the samples where developed in a M1BK 1PA solution with a 1 3 composition. Finally, silver was thermally evaporated and Ufted-off to remove of the unwanted residual metal areas. The total number of nano-antennas created was 6.25 x 10 distributed over an area of 2.13 mm. Although the final array of nano-antennas was laid on top of a dielectric layer of silicon dioxide, the silicon substrate obstructed the transmitted light. In Fig. 1.21, SEM pictures at different magnifications show the obtained results through this process. The two transversal nano-antennas in an L shape form a... 

A possible procedure for synthetic jet fabrication has been shown in Fig. 3. The first step in the fabrication process is the wet etching of the silicon wafer using KOH to form a cavity. The cavity is filled with electroplated nickel in the second step. A polyimide membrane is deposited over the silicon wafer using spin coating in the third step. The back side of the silicon substrate is etched using KOH to obtain the orifice hole. The orifice hole extends till the filled nickel inside the cavity and the nickel material are also etched away. The piezo-ceramic material is deposited on top of the membrane for actuation. In case of electrostatic-based actuation, aluminum electrode is deposited on the membrane. 

We illustrate CNT-polymer interface morphology using a CNT/PS and a CNT/ epoxy system." Rod specimen of CNT/PS composite with 1 mm diameter was fabricated using an extrusion process, with a CNT content of about 1 wt.%. Tensile failure surfaces of the CNT/PS composite rod were examined under a field emission seanning electronic microscope (FESEM) and transmission electron microscope (TEM). CNT/epoxy (EPON SU-8 photo resist) thin film with 0.1 wt.% CNT and 5.8/xm in thickness was fabricated by spin-coating mixture of CNT and epoxy on to a silicon wafer. The fracture surface of CNT/ epoxy specimens was examined under FESEM and TEM after shaft-loaded test (inset of Fig. 13.7). 

Fabrication of carbonaceous microstructures has been reported also by Malladi et al. by spin-coating an SU-8 photoresistant material on a Si wafer. The photoresist material is coated on a Si wafer under a UV mask that transfers the pattern, which undergoes pyrolysis at 900°C in Nj atmosphere. This process allows the fabrication of suspended carbon microelec-tromechanical systems (C-MEMS), which are highly appreciated on sensor applications. 

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