Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNo...Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNoD) as the interface for transmitting Rayleigh wave was studied extensively .However,in all cases,nano crystalline or microcrystalline AlN coatings were deposited,typically by sputtering or CVD,on polycrystalline diamond film.The diamond film itself may contain nano or micro grains that are deposited by CVD.The presence of extensive grain boundaries in AlN can attenuate rapidly the propagation of Rayleigh wave.Moreover,the bonding between loose atomic packing of AlN and tight lattice of diamond is weak so much of the mechanical energy is dissipated as heat.In fact,the energy loss is much higher than energy transmitted during the resonating process.In this research,we attempted to improve the matching of atoms at the interface of AlNoD by doping AlN lattice with boron atoms.The shrinking of the lattice may allow more atoms are aligned at the interface.Moreover,a method of coupling single crystal AlN on single crystal diamond is proposed.Such a coupling can maximize the signal-to-noise ratio of the resonating AlNoD at the same time minimize the insertion loss of the SAW filter.展开更多
Great interest in surface acoustic wave device based on diamond is attracted because diamond has the highest surface acoustic wave velocity of all substrates.In this paper,400 nm ZnO film was deposited on polycrystall...Great interest in surface acoustic wave device based on diamond is attracted because diamond has the highest surface acoustic wave velocity of all substrates.In this paper,400 nm ZnO film was deposited on polycrystalline diamond wafer by magnetron sputtering.The experimental results indicate that highly c-axis oriented and fine-grain polycrystalline ZnO films have been obtained.100 nm Al thin film was deposited on ZnO/diamond by electron evaporation.Standard interdigital-transducers with the electrodes of 1.0μm width were fabricated on the Al film using photolithography and reactive ion etching (RIE) processes.A 2.48 GHz longitudinally-coupled double-mode surface acoustic wave filter has been successfully fabricated using the Al/ZnO/diamond structure.展开更多
Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas ...Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas the arc currents of FCA were 20, 40, 60 and 80 A. The effects of arc current on the structure, surface roughness, density and mechanical properties of SiNx/DLC films were investigated. The results show that the arc current in the studied range has effect on the structure, surface roughness, density and mechanical properties of composite SiNx/DLC films. The composite SiNx/DLC films show the sp3 content between 53.5% and 66.7%, density between 2.54 and2.98 g/cm3, stress between 1.7 and 2.2 GPa, and hardness between 35 and 51 GPa. Furthermore, it was found that the density, stress and hardness correlate linearly with the sp3 content for composite SiNx/DLC films.展开更多
文摘Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNoD) as the interface for transmitting Rayleigh wave was studied extensively .However,in all cases,nano crystalline or microcrystalline AlN coatings were deposited,typically by sputtering or CVD,on polycrystalline diamond film.The diamond film itself may contain nano or micro grains that are deposited by CVD.The presence of extensive grain boundaries in AlN can attenuate rapidly the propagation of Rayleigh wave.Moreover,the bonding between loose atomic packing of AlN and tight lattice of diamond is weak so much of the mechanical energy is dissipated as heat.In fact,the energy loss is much higher than energy transmitted during the resonating process.In this research,we attempted to improve the matching of atoms at the interface of AlNoD by doping AlN lattice with boron atoms.The shrinking of the lattice may allow more atoms are aligned at the interface.Moreover,a method of coupling single crystal AlN on single crystal diamond is proposed.Such a coupling can maximize the signal-to-noise ratio of the resonating AlNoD at the same time minimize the insertion loss of the SAW filter.
文摘Great interest in surface acoustic wave device based on diamond is attracted because diamond has the highest surface acoustic wave velocity of all substrates.In this paper,400 nm ZnO film was deposited on polycrystalline diamond wafer by magnetron sputtering.The experimental results indicate that highly c-axis oriented and fine-grain polycrystalline ZnO films have been obtained.100 nm Al thin film was deposited on ZnO/diamond by electron evaporation.Standard interdigital-transducers with the electrodes of 1.0μm width were fabricated on the Al film using photolithography and reactive ion etching (RIE) processes.A 2.48 GHz longitudinally-coupled double-mode surface acoustic wave filter has been successfully fabricated using the Al/ZnO/diamond structure.
文摘Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas the arc currents of FCA were 20, 40, 60 and 80 A. The effects of arc current on the structure, surface roughness, density and mechanical properties of SiNx/DLC films were investigated. The results show that the arc current in the studied range has effect on the structure, surface roughness, density and mechanical properties of composite SiNx/DLC films. The composite SiNx/DLC films show the sp3 content between 53.5% and 66.7%, density between 2.54 and2.98 g/cm3, stress between 1.7 and 2.2 GPa, and hardness between 35 and 51 GPa. Furthermore, it was found that the density, stress and hardness correlate linearly with the sp3 content for composite SiNx/DLC films.
