CMOS-compatible RF/microwave devices,such as filters and amplifiers,have been widely used in wireless communication systems.However,secondary-electron emission phenomena often occur in RF/microwave devices based on si...CMOS-compatible RF/microwave devices,such as filters and amplifiers,have been widely used in wireless communication systems.However,secondary-electron emission phenomena often occur in RF/microwave devices based on silicon(Si)wafers,especially in the high-frequency range.In this paper,we have studied the major factors that influence the secondary-electron yield(SEY)in commercial Si wafers with different doping concentrations.We show that the SEY is suppressed as the doping concentration increases,corresponding to a relatively short effective escape depthλ.Meanwhile,the reduced narrow band gap is beneficial in suppressing the SEY,in which the absence of a shallow energy band below the conduction band will easily capture electrons,as revealed by first-principles calculations.Thus,the new physical mechanism combined with the effective escape depth and band gap can provide useful guidance for the design of integrated RF/microwave devices based on Si wafers.展开更多
This research has successfully developed an advance d manufacturing system for 300mm silicon wafer,using fixed abrasive instead o f conventional free slurry,to provide a totally integrated solution for achievi ng the ...This research has successfully developed an advance d manufacturing system for 300mm silicon wafer,using fixed abrasive instead o f conventional free slurry,to provide a totally integrated solution for achievi ng the surface roughness Ra<1 nm(Ry<5～6 nm) and the global flatness<O.2μm /300 mm.In addition to high throughput rate,this system significantly reduc es the total energy consumption by 70%,compared with the current process used for 200mm Si wafer.This paper describes the principle of material removal,st ate-of-the-art technologies and kinematical analysis for one-stop finishing o f 300mm Si wafer by fixed abrasive process.展开更多
An apparatus was specifically developed for micro-friction and adhesion measurements. The force measurement range is 10-2000 μN with a horizontal speed of 10-400 μm/s. The apparatus was tested using a 0.7-mm diamete...An apparatus was specifically developed for micro-friction and adhesion measurements. The force measurement range is 10-2000 μN with a horizontal speed of 10-400 μm/s. The apparatus was tested using a 0.7-mm diameter steel ball as the upper specimen to measure the micro friction and adhesion behaviour of a Si （100） wafer and a TiB2 film. The effects of rest time, speed, and load were studied. The results show that the maximum static and sliding friction forces of both the Si （100） wafer and the TiB2 film increase with the load. At low speeds, the influence of speed on the friction force is significant. The adhesion forces of the Si （100） wafer and the TiB2 film increase with rest time, reaching stable values after about 3000 s. The TiB2 film has significantly less adhesion and micro friction forces than the Si （100） wafer.展开更多
To find out the causation of inhomogeneous minority carrier lifetime distribution in high quality multicrystalline silicon （mc-Si） wafers, impurities and lattice defects were systematically studied by means of Fouri...To find out the causation of inhomogeneous minority carrier lifetime distribution in high quality multicrystalline silicon （mc-Si） wafers, impurities and lattice defects were systematically studied by means of Fourier transform infrared （FTIR） spectroscopy and metallography, Inhomogeneously distributed oxygen impurity and dislocations were demonstrated to be key leading factors, and the restriction mechanism was discussed. Scattering process caused by ionized impurities and dislocations decreased carrier mobility, while carrier concentration was not significantly affected. Measurements showed that resistivity was higher and more dispersive in low lifetime area. Solar cells were fabricated with these wafers. Cells＇ efficiency of inhomogeneous ones exhibited averagely 0.27% lower than the regular ones in absolute terms. Recombination centers and leakage loss induced by dislocations and impurities led to the reduction in shunt resistors and open-circuit voltage, and then affected the performance of cells.展开更多
The advantages of the extended gate field effect transistor (EGFET) compared with the ion sensitive field effect transistor (ISFET) are easy package,easy preservation,insensitive light effect,and better stability.Al...The advantages of the extended gate field effect transistor (EGFET) compared with the ion sensitive field effect transistor (ISFET) are easy package,easy preservation,insensitive light effect,and better stability.Although EGFET has above advantages,there are still some non-ideal effects such as drift etc..The drift behavior exists during the measurement process and results in the variation of the output voltage with time.We can obtain the drift value by immersing EGFET into the pH solution for 12 hours and measure the rate of the output voltage versus time after S hours.This study analyzes the sensitivity, stability,and drift effect of the EGFET based on the structure of the ruthenium oxide/silicon (RuO_x/Si) wafer for measuring the potassium ion.The fabrication of the potassium ion sensor can be widely employed in medical detection.展开更多
基金Project supported by the Administration of Science,Technology and Industry of National Defense of China (Grant No.HTKJ2021KL504001)the National Natural Science Foundation of China (Grant Nos.12004297 and 12174364)+3 种基金the China Postdoctoral Science Foundation (Grant No.2022M712507)the Fundamental Research Funds for the Central Universities (Grant No.xzy01202003)the National 111 Project of China (Grant No.B14040)the support from the Instrument Analysis Center of Xi’an Jiaotong University。
文摘CMOS-compatible RF/microwave devices,such as filters and amplifiers,have been widely used in wireless communication systems.However,secondary-electron emission phenomena often occur in RF/microwave devices based on silicon(Si)wafers,especially in the high-frequency range.In this paper,we have studied the major factors that influence the secondary-electron yield(SEY)in commercial Si wafers with different doping concentrations.We show that the SEY is suppressed as the doping concentration increases,corresponding to a relatively short effective escape depthλ.Meanwhile,the reduced narrow band gap is beneficial in suppressing the SEY,in which the absence of a shallow energy band below the conduction band will easily capture electrons,as revealed by first-principles calculations.Thus,the new physical mechanism combined with the effective escape depth and band gap can provide useful guidance for the design of integrated RF/microwave devices based on Si wafers.
文摘This research has successfully developed an advance d manufacturing system for 300mm silicon wafer,using fixed abrasive instead o f conventional free slurry,to provide a totally integrated solution for achievi ng the surface roughness Ra<1 nm(Ry<5～6 nm) and the global flatness<O.2μm /300 mm.In addition to high throughput rate,this system significantly reduc es the total energy consumption by 70%,compared with the current process used for 200mm Si wafer.This paper describes the principle of material removal,st ate-of-the-art technologies and kinematical analysis for one-stop finishing o f 300mm Si wafer by fixed abrasive process.
基金the National Natural Science Foundation of China (No. 50475012)the National Key Basic Research and Devel-opment (973) Program (No. 2003CB716201)
文摘An apparatus was specifically developed for micro-friction and adhesion measurements. The force measurement range is 10-2000 μN with a horizontal speed of 10-400 μm/s. The apparatus was tested using a 0.7-mm diameter steel ball as the upper specimen to measure the micro friction and adhesion behaviour of a Si （100） wafer and a TiB2 film. The effects of rest time, speed, and load were studied. The results show that the maximum static and sliding friction forces of both the Si （100） wafer and the TiB2 film increase with the load. At low speeds, the influence of speed on the friction force is significant. The adhesion forces of the Si （100） wafer and the TiB2 film increase with rest time, reaching stable values after about 3000 s. The TiB2 film has significantly less adhesion and micro friction forces than the Si （100） wafer.
基金financially supported by the Department of Education of Guangdong Province(Grant No.2013CXZDA002)Guangzhou Science and Technology Department(Grant No.2014Y2-00221)
文摘To find out the causation of inhomogeneous minority carrier lifetime distribution in high quality multicrystalline silicon （mc-Si） wafers, impurities and lattice defects were systematically studied by means of Fourier transform infrared （FTIR） spectroscopy and metallography, Inhomogeneously distributed oxygen impurity and dislocations were demonstrated to be key leading factors, and the restriction mechanism was discussed. Scattering process caused by ionized impurities and dislocations decreased carrier mobility, while carrier concentration was not significantly affected. Measurements showed that resistivity was higher and more dispersive in low lifetime area. Solar cells were fabricated with these wafers. Cells＇ efficiency of inhomogeneous ones exhibited averagely 0.27% lower than the regular ones in absolute terms. Recombination centers and leakage loss induced by dislocations and impurities led to the reduction in shunt resistors and open-circuit voltage, and then affected the performance of cells.
文摘The advantages of the extended gate field effect transistor (EGFET) compared with the ion sensitive field effect transistor (ISFET) are easy package,easy preservation,insensitive light effect,and better stability.Although EGFET has above advantages,there are still some non-ideal effects such as drift etc..The drift behavior exists during the measurement process and results in the variation of the output voltage with time.We can obtain the drift value by immersing EGFET into the pH solution for 12 hours and measure the rate of the output voltage versus time after S hours.This study analyzes the sensitivity, stability,and drift effect of the EGFET based on the structure of the ruthenium oxide/silicon (RuO_x/Si) wafer for measuring the potassium ion.The fabrication of the potassium ion sensor can be widely employed in medical detection.
