In this work the system for reactive ion etching and mechanism of directional etching with SF6/O2 chemistry are described. Basic process parameters were investigated and results of etching were implemented into fabrication of silicon microstructures. A typical result of etching is: etch rate 1 to 2 µm/min, lateral undercut 5-6% in respect to the etch depth, aspect ratio less than 6 and selectivity to oxide and photoresist masks 100 and 20, respectively.
COBISS.SI-ID: 9312596
Anodic bonding of silicon-glass substrates with prefabricated structures which included micromachined or patterned topography on one or on both of the mating surfaces was investigated. In this study, Pyrex 7740 (Corning) and Borofloat 33 (Schott) glass wafers were bonded to bare silicon and to SiO2 /Si terminated structures in the temperature range 350–400 °C in the air ambient under applied anodic voltages between 800–1800 V. Proper surface treatment and cleaning steps were developed to provide extremely clean and hydrophilic surfaces, thus enabling the formation of uniform and strong bond between the two surfaces. In addition, void free glass-Si-glass as well as multilayer microstructures were successfully bonded by applying appropriate configuration of connecting electrodes.
COBISS.SI-ID: 9435988
Silicon planar diffused photodiode appropriate for photoplethysmography (PPG) was evaluated in the presented preliminary study. Design and fabrication of both, silicon photodiode and reflection mode PPG prototype is described with emphasis on biocompatibility. During PPG prototype characterization on left hand index fingertip, three operating modes of photodiode, open-circuit, photovoltaic, and photoconductive mode, were evaluated. Next, the influence of photodiode dark current and serial resistance on PPG response is analyzed and discussed.
COBISS.SI-ID: 9524564