Russia Creates Diamond MEMS Resonators Successfully Simulated Ultrasensitive Sensors
2018-04-20 14:00:04
According to a researcher at the Moscow Institute of Physics and Technology (MIPT), this "sound wave" resonator that is faster than silicon piezoelectric has successfully simulated ultra-sensitive sensors. Break new records in the microwave field.
Typical piezoelectric layered structure The MIPT Superhard and Novelty Carbon Material Technology Institute (TISNCM) and the Siberian Federal University have jointly achieved this breakthrough, the diamond-based MEMS resonator, which can sustain more than 2,000 while surpassing the speed of 20GHz. The quality factor (Q). This performance can be used not only to generate high-speed frequency signals, but also to create ultra-sensitive surface and bulk acoustic wave (SAW/BAW) resonators to achieve biosensors that can detect the number of neighboring single bacteria and other nano-level toxicants.
“Many studies have focused on high-frequency SAW/BAW resonators. Several reports have achieved extremely high frequency results, but their Q values ​​are quite low,†said TISNCM researcher Arseniy Telichko. “Our diamond components are operational. At frequencies in the tens of GHz range, and just by adjusting its parameters such as thickness, width, and electrode material, the results of near-model single-microbe detection can be produced."
Russian researchers said that by fine-tuning its high pressure (HPHT) deposition process, it has achieved superior performance over other studies. Most other researchers use slow-growing chemical vapor deposition (CVD) processes, and TISNCM's approach is not only faster but also produces a more perfect lattice.
“The point is that other authors often use CVD diamonds that are created with relatively slow carbon deposition. The diamond crystals slowly 'grow' to form a thin film, but this CVD growth pattern causes the diamonds to be stress--a variety of internal forces. Crystals lead to imbalances." Therefore, Telichko pointed out, "through HPHT, we have grown using single-crystal diamonds made of almost pure carbon. Therefore, our diamonds are actually single crystals with minimal internal stress in the structure. So, this Single-crystal diamond-based components can operate at higher frequencies, have a higher quality factor, and are generally better than CVD diamonds."
Telichko pointed out that the key to better quality applications with its purely crystalline substrate lies in the stacking of piezoelectric materials on a substrate with two metal interlayers (aluminum and molybdenum). Therefore, the structure of the resonator can not only achieve a higher frequency but also simultaneously achieve a higher Q value.
“In the high-frequency BAW resonator structure we studied, all the parameters were mainly determined by the substrate material. Using HPHT diamond instead of quartz or even CVD diamond substrate can achieve better performance, higher Q value, and more. High operating frequency (up to 20GHz) and lower loss components,†said Telichko. "Recently we have been able to show that diamond attenuation can achieve linear frequency correlation after 1-GHz, while other crystals are still square correlation. This means that diamond attenuation (energy consumption) after 1-GHz is more than other crystals. Low makes diamonds an ideal substrate for high-frequency electronics applications."
Telichko stated that MIPT had created a number of diamond resonators in its experimental research, both capable of exhibiting >20-GHz operational capabilities, “it is the latest world record written by this type of component.†However, the research team noticed in this At a velocity, mixing occurs near harmonics, which explains Lamb-mode waveforms—elastic waves that depend on SAW/BAW plane motion.
In order to optimize performance, Russian researchers adjusted the Lamb-wave propagation method. Using finite element analysis, the propagation of this acoustic wave in a layered piezoelectric structure can be analyzed in detail and its phase velocity profile can be plotted.
In the future, researchers plan to use other new materials to realize piezoelectric films, thereby avoiding Lamb waves caused by peak wave mixing.
(Original title: Russian scientists create diamond MEMS resonators)
Typical piezoelectric layered structure
“Many studies have focused on high-frequency SAW/BAW resonators. Several reports have achieved extremely high frequency results, but their Q values ​​are quite low,†said TISNCM researcher Arseniy Telichko. “Our diamond components are operational. At frequencies in the tens of GHz range, and just by adjusting its parameters such as thickness, width, and electrode material, the results of near-model single-microbe detection can be produced."
Russian researchers said that by fine-tuning its high pressure (HPHT) deposition process, it has achieved superior performance over other studies. Most other researchers use slow-growing chemical vapor deposition (CVD) processes, and TISNCM's approach is not only faster but also produces a more perfect lattice.
“The point is that other authors often use CVD diamonds that are created with relatively slow carbon deposition. The diamond crystals slowly 'grow' to form a thin film, but this CVD growth pattern causes the diamonds to be stress--a variety of internal forces. Crystals lead to imbalances." Therefore, Telichko pointed out, "through HPHT, we have grown using single-crystal diamonds made of almost pure carbon. Therefore, our diamonds are actually single crystals with minimal internal stress in the structure. So, this Single-crystal diamond-based components can operate at higher frequencies, have a higher quality factor, and are generally better than CVD diamonds."
Telichko pointed out that the key to better quality applications with its purely crystalline substrate lies in the stacking of piezoelectric materials on a substrate with two metal interlayers (aluminum and molybdenum). Therefore, the structure of the resonator can not only achieve a higher frequency but also simultaneously achieve a higher Q value.
“In the high-frequency BAW resonator structure we studied, all the parameters were mainly determined by the substrate material. Using HPHT diamond instead of quartz or even CVD diamond substrate can achieve better performance, higher Q value, and more. High operating frequency (up to 20GHz) and lower loss components,†said Telichko. "Recently we have been able to show that diamond attenuation can achieve linear frequency correlation after 1-GHz, while other crystals are still square correlation. This means that diamond attenuation (energy consumption) after 1-GHz is more than other crystals. Low makes diamonds an ideal substrate for high-frequency electronics applications."
Telichko stated that MIPT had created a number of diamond resonators in its experimental research, both capable of exhibiting >20-GHz operational capabilities, “it is the latest world record written by this type of component.†However, the research team noticed in this At a velocity, mixing occurs near harmonics, which explains Lamb-mode waveforms—elastic waves that depend on SAW/BAW plane motion.
In order to optimize performance, Russian researchers adjusted the Lamb-wave propagation method. Using finite element analysis, the propagation of this acoustic wave in a layered piezoelectric structure can be analyzed in detail and its phase velocity profile can be plotted.
In the future, researchers plan to use other new materials to realize piezoelectric films, thereby avoiding Lamb waves caused by peak wave mixing.
(Original title: Russian scientists create diamond MEMS resonators)