Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are ch...Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.展开更多
In recent years,simulated annealing algorithms have been extensively developed and utilized to solve multi-objective optimization problems.In order to obtain better optimization performance,this paper proposes a Novel...In recent years,simulated annealing algorithms have been extensively developed and utilized to solve multi-objective optimization problems.In order to obtain better optimization performance,this paper proposes a Novel Adaptive Simulated Annealing (NASA) algorithm for constrained multi-objective optimization based on Archived Multi-objective Simulated Annealing (AMOSA).For handling multi-objective,NASA makes improvements in three aspects:sub-iteration search,sub-archive and adaptive search,which effectively strengthen the stability and efficiency of the algorithm.For handling constraints,NASA introduces corresponding solution acceptance criterion.Furthermore,NASA has also been applied to optimize TD-LTE network performance by adjusting antenna parameters;it can achieve better extension and convergence than AMOSA,NSGAII and MOPSO.Analytical studies and simulations indicate that the proposed NASA algorithm can play an important role in improving multi-objective optimization performance.展开更多
The In-N clusters form in the dilute nitride InxGa1-xNy As1-yalloys after annealing.It is found that the formation of the In-N clusters not only raises the N levels lying above the conduction band minimum(CBM)of In Ga...The In-N clusters form in the dilute nitride InxGa1-xNy As1-yalloys after annealing.It is found that the formation of the In-N clusters not only raises the N levels lying above the conduction band minimum(CBM)of In GaA s,but also raises the N levels below the CBM of In GaA s,leading to the variation of the impurity-host interaction.The blueshift of the band gap energy is relative to the variation of the impurity-host interaction.In order to describe the blueshift of the band gap energy due to the formation of the In-N clusters,a model is developed.It is found that the model can describe the blueshift of the band gap energy well.In addition,it is found the blueshift of the band gap energy due to the atom interdiffusion at the interface can be larger than that due to the formation of the In-N clusters.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61176092,61036003,and 60837001)the National Basic Research Program of China (Grant No. 2012CB933503)+1 种基金the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20110121110025)the Fundamental Research Funds for the Central Universities,China (Grant No. 2010121056)
文摘Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.
基金supported by the Major National Science & Technology Specific Project of China under Grants No.2010ZX03002-007-02,No.2009ZX03002-002,No.2010ZX03002-002-03
文摘In recent years,simulated annealing algorithms have been extensively developed and utilized to solve multi-objective optimization problems.In order to obtain better optimization performance,this paper proposes a Novel Adaptive Simulated Annealing (NASA) algorithm for constrained multi-objective optimization based on Archived Multi-objective Simulated Annealing (AMOSA).For handling multi-objective,NASA makes improvements in three aspects:sub-iteration search,sub-archive and adaptive search,which effectively strengthen the stability and efficiency of the algorithm.For handling constraints,NASA introduces corresponding solution acceptance criterion.Furthermore,NASA has also been applied to optimize TD-LTE network performance by adjusting antenna parameters;it can achieve better extension and convergence than AMOSA,NSGAII and MOPSO.Analytical studies and simulations indicate that the proposed NASA algorithm can play an important role in improving multi-objective optimization performance.
基金Supported by the National Natural Science Foundation of China under Grant No.61504094Tinjin Research Program of Application Foundation and Advanced Technology under No.15JCYBJC16300Tianjin City High School Science and Technology Fund Planning Project No.20120609
文摘The In-N clusters form in the dilute nitride InxGa1-xNy As1-yalloys after annealing.It is found that the formation of the In-N clusters not only raises the N levels lying above the conduction band minimum(CBM)of In GaA s,but also raises the N levels below the CBM of In GaA s,leading to the variation of the impurity-host interaction.The blueshift of the band gap energy is relative to the variation of the impurity-host interaction.In order to describe the blueshift of the band gap energy due to the formation of the In-N clusters,a model is developed.It is found that the model can describe the blueshift of the band gap energy well.In addition,it is found the blueshift of the band gap energy due to the atom interdiffusion at the interface can be larger than that due to the formation of the In-N clusters.
