Forschungszentrum Mikrotechnik
Refine
Year of publication
Document Type
- Conference Proceeding (137)
- Article (104)
- Preprint (4)
- Part of a Book (3)
- Doctoral Thesis (2)
- Book (1)
- Habilitation (1)
- Other (1)
Institute
- Forschungszentrum Mikrotechnik (253)
- Josef Ressel Zentrum für Materialbearbeitung (28)
- Forschungszentrum Digital Factory Vorarlberg (7)
- Forschung (6)
- Technik | Engineering & Technology (3)
- Department of Engineering (Ende 2021 aufgelöst; Integration in die übergeordnete OE Technik) (2)
- Forschungszentrum Energie (2)
- Department of Computer Science (Ende 2021 aufgelöst; Integration in die übergeordnete OE Technik) (1)
- Forschungszentrum Human Centred Technologies (1)
- Josef Ressel Zentrum für Robuste Entscheidungen (1)
Language
- English (247)
- German (5)
- Multiple languages (1)
Keywords
- Laser ablation (11)
- Y-branch splitter (11)
- arrayed waveguide gratings (11)
- photonics (8)
- integrated optics (6)
- Arrayed waveguide gratings (5)
- MMI splitter (5)
- OCT (5)
- insertion loss (5)
- AWG (4)
We have investigated the ablation behaviour of single crystal SrTiO3 <100> with focus on the influence of the pulse duration at a wavelength of 248 nm. The experiments were performed with KrF-excimer lasers with pulse durations of 34 ns and 500 fs, respectively. Femtosecond-ablation turns out to be more efficient by one order of magnitude and to eliminate the known problem of cracking of SrTiO3 during laser machining with longer pulses. In addition, the cavities ablated with femtosecond pulses display a smoother surface with no indication of melting and well-defined, sharp edges. These effects can be explained by the reduced thermal shock effect on the material by using ultrashort pulses.
The properties of diamond make it an attractive material for MEMS and sensor devices. We present the feasibility to fabricate membranes and cantilevers made of nano-(micro-) crystalline diamond films grown on Si/SiO2 substrates using microwave chemical vapour deposition (MWCVD). The patterning of micromechanical structures was performed by a combined process of femtosecond laser ablation and wet etching. We designed cantilever structures with varying lengths and widths (25, 50, 100, 200 and 300 μm). The cantilevers were made in a symmetric left- and right-hand configuration. An additional laser treatment was used to modify the mechanical properties of the left-hand cantilever. The deflection of the laser-treated, and non-treated sections was measured. The global mechanical system properties were simulated and corresponded with high accuracy to the measured results of deflection.
The properties of SiC and diamond make them attractive materials for MEMS and sensor devices. We innovated specific laser ablation techniques to fabricate membranes and cantilevers made of SiC or nano-(micro-) crystalline diamond films grown on Si/SiO2 substrates by microwave chemical vapour deposition (MWCVD). We started research to generate surface moulds to grow corrugated diamond films for membranes and cantilevers. A software tool was developed to support the design of micromechanical cantilevers. We can measure deformation and resonant frequency of diamond cantilevers and identify the global mechanical properties. A benchmark against finite element simulations enables an inverse identification of the specific system parameters and simplifies the characterization procedure.
Femtosecond laser ablation on Si generates 2D ripple structures, known as laser induced periodic surface structures (LIPSS) and pinholes. We fabricated membranes with 20 to 50 μm thickness perforated by an array of tapered pinholes up to 5 μm in diameter and 10 to 20 μm spacing. Within several micrometer the pinholes transform into hollow photonic waveguides with constant diameter from 1μm to 2μm. Such structures offer a 3D photonic coupling device for polymer Y-branch- and MMI-splitter. We measured a considerable change of electrical resistivity for 500 ppm H2 in air using Si/SiO2/TiO2 substrates with 2D LIPSS. We propose to investigate 3D waveguide arrays also for photonic-chemical sensors.
By a simple femtosecond laser process, we fabricated metal-oxide/gold composite films for electrical and optical gas sensors. We designed a dripple wavelength AWG-spectrometer, matched to the plasma absorption wavelength region of the composite films. H2/CO absorptions fit well with the AWG design for multi gas detection sensor arrays