The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demon...The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient. As the RTA duration times increased, the oxygen precipitate density increased and the denuded zone depth decreased. X-ray photoelectron spectroscopy （XPS） data and atomic force microscope （AFM） results show that there RTA process,which can explain the different effect of RTA was a surface nitriding reaction during the N2/NH3 ambient ambient.展开更多
Durability zonation standard （DZS） is proposed to provide useful parameters for durable concrete structure design. It deals not only with the influence of environment on structures, but also with types, functions an...Durability zonation standard （DZS） is proposed to provide useful parameters for durable concrete structure design. It deals not only with the influence of environment on structures, but also with types, functions and importance of structures based on the theory of life cycle cost（LCC）. First, the basic concept of DZS for concrete structure design is defined. Then the basic principles for DZS are established. The factors for zonation according to natural environmental conditions and structural importance are identified. The usefulness of DZS by citing a real application for concrete highway bridges in Zhejiang Province is demonstrated. Finally, durability regulations are provided accordingly to zonation.展开更多
文摘The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient. As the RTA duration times increased, the oxygen precipitate density increased and the denuded zone depth decreased. X-ray photoelectron spectroscopy （XPS） data and atomic force microscope （AFM） results show that there RTA process,which can explain the different effect of RTA was a surface nitriding reaction during the N2/NH3 ambient ambient.
基金The Key Project of National Natural Science Foun-dation of China (No50538070)
文摘Durability zonation standard （DZS） is proposed to provide useful parameters for durable concrete structure design. It deals not only with the influence of environment on structures, but also with types, functions and importance of structures based on the theory of life cycle cost（LCC）. First, the basic concept of DZS for concrete structure design is defined. Then the basic principles for DZS are established. The factors for zonation according to natural environmental conditions and structural importance are identified. The usefulness of DZS by citing a real application for concrete highway bridges in Zhejiang Province is demonstrated. Finally, durability regulations are provided accordingly to zonation.
