In the current work, in situ surface passivation Ge substrate by using trimethylaluminum（TMA） prior to HfTiO films deposition and electrical properties of HfTiO/Ge gate stacks have been investigated by X-ray photoel...In the current work, in situ surface passivation Ge substrate by using trimethylaluminum（TMA） prior to HfTiO films deposition and electrical properties of HfTiO/Ge gate stacks have been investigated by X-ray photoelectron spectroscopy（XPS） and electrical measurements systematically. Based on analysis from XPS measurements, it has been confirmed that the interfacial layer of HfTiO/Ge gate stack has been suppressed effectively after 20 half-ALD cycles TMA pretreatment. Electrical properties of metal-oxidesemiconductor（MOS） capacitor based on HfTiO gate dielectrics have shown that the MOS capacitor with20 cycles TMA cleaning exhibits the lowest interface state density（~7.56 eV^（-1）cm^（-2）） and the smallest leakage current（~2.67 × 10^（-5）A/cm^2）. Correspondingly, the leakage current conduction mechanisms for MOS capacitor device with 20 cycles TMA cleaning also have been discussed in detail.展开更多
In this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of A1Me3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the i...In this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of A1Me3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the iron-catalyzed ethylene oligomerization. The molar ratios of [PhOH]/[AlMe3] and [H2O]/[Al] during the preparation were explored and their impacts on the oligomerization activity and product distribution were discussed. To obtain the effective activators with good polymer-retarding effect and relatively high activity, the optimized conditions were proposed to be [PhOH]/[AlMe3] = 0.5 and [H2O]/[Al] = 0.7. Various aluminoxanes with different [-OH] sources confirmed the importance of using phenols in preparing the effective polymer-retarding activators. By utilizing these aryloxy-aluminoxanes, the mass fraction of polymers in the total products could be reduced to lower than 1.0 wt%, which is much lower than that of the MAO-activated systems （〉 30 wt%）. This is a potential benefit for the industrial application of the iron-catalyzed oligomerization process.展开更多
基金support from the National Natural Science Foundation of China (Nos. 51572002, 11474284)the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of China (No. J05015131)the Anhui Provincial Natural Science Foundation (No. 1608085MA06)
文摘In the current work, in situ surface passivation Ge substrate by using trimethylaluminum（TMA） prior to HfTiO films deposition and electrical properties of HfTiO/Ge gate stacks have been investigated by X-ray photoelectron spectroscopy（XPS） and electrical measurements systematically. Based on analysis from XPS measurements, it has been confirmed that the interfacial layer of HfTiO/Ge gate stack has been suppressed effectively after 20 half-ALD cycles TMA pretreatment. Electrical properties of metal-oxidesemiconductor（MOS） capacitor based on HfTiO gate dielectrics have shown that the MOS capacitor with20 cycles TMA cleaning exhibits the lowest interface state density（~7.56 eV^（-1）cm^（-2）） and the smallest leakage current（~2.67 × 10^（-5）A/cm^2）. Correspondingly, the leakage current conduction mechanisms for MOS capacitor device with 20 cycles TMA cleaning also have been discussed in detail.
基金support and encouragement of the National Natural Science Foundation of China(Nos.U1663222 and 21176208)
文摘In this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of A1Me3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the iron-catalyzed ethylene oligomerization. The molar ratios of [PhOH]/[AlMe3] and [H2O]/[Al] during the preparation were explored and their impacts on the oligomerization activity and product distribution were discussed. To obtain the effective activators with good polymer-retarding effect and relatively high activity, the optimized conditions were proposed to be [PhOH]/[AlMe3] = 0.5 and [H2O]/[Al] = 0.7. Various aluminoxanes with different [-OH] sources confirmed the importance of using phenols in preparing the effective polymer-retarding activators. By utilizing these aryloxy-aluminoxanes, the mass fraction of polymers in the total products could be reduced to lower than 1.0 wt%, which is much lower than that of the MAO-activated systems （〉 30 wt%）. This is a potential benefit for the industrial application of the iron-catalyzed oligomerization process.
