Investigations on surface decomposition of GaN implanted with low energy (80 keV) Eu ion to a low dose (l×1014 cm-2), and its annealing behavior under high temperature (1050℃) in N2 are performed. The as-grown, ...Investigations on surface decomposition of GaN implanted with low energy (80 keV) Eu ion to a low dose (l×1014 cm-2), and its annealing behavior under high temperature (1050℃) in N2 are performed. The as-grown, as-implanted and annealed GaN films are characterized by proton elastic scattering (PES), Rutherford backscattering spectrometry (RBS), photoluminescence (PL) and atomic force microscopy (AFM). The results show that Eu ion implantation induces radiation defects and decomposition of GaN. The GaN surface decomposition is more serious during high temperature annealing. The atomic ratio of N in as-grown, as-implanted and annealed GaN film is 47 at.%, 44 at.% and 40 at.%, respectively. As a result, a rough Ga-rich layer is formed at the surface, though the lattice defects are partly removed after high temperature annealing.展开更多
The effect of a 0.9 nm Mo interlayer at the interface of Ti film deposited on a Si substrate on phase formation of TiSi2 during annealing has been studied by using transmission electron micro-diffraction technique. Wh...The effect of a 0.9 nm Mo interlayer at the interface of Ti film deposited on a Si substrate on phase formation of TiSi2 during annealing has been studied by using transmission electron micro-diffraction technique. When Ti/Mo/Si was an- nealed at low temperature as 550℃ for 30 mm in Ar ambient, a metastable phase. i.e., hexagonal C40 TiSi2, and the equilibrium phase. i.e., orthorhombic C54 TiSi2, were both detected. The experimental patterns of the C40 and C54 compare well with the simulated ones.展开更多
Annealing behavior, at different annealing temperatures, of an ultrathin Mo layer located between a Ti film and Si substrate or deposited on the top of sur -face of a Ti film was investigated by Rutherford baccscatter...Annealing behavior, at different annealing temperatures, of an ultrathin Mo layer located between a Ti film and Si substrate or deposited on the top of sur -face of a Ti film was investigated by Rutherford baccscattering spectrometry (RBS), cross-sectional transmission electron microscopy (TEM) and energy dispersive X-ray spectrometry (EDS). In a Ti/Mo/Si structure, partially reacted film with layer struc- ture of Ti-rich silicide/TiSi2/(Mo, Ti)Si2 on a Si substrate was formed after 550℃ annealing for 30 min. The ratio of Mo to Ti in (Mo, Ti)Si2 layer decreases from ncar Si substrate upwards and becomes zero at about 20 nm away. In a Mo/Ti/Si structure, the surface Mo layer enhances the Si diffusion from the substrate during annealing. Mo bearing Ti rich silicide exists on the surface until 600℃ and then converts to (Mo, Ti)Si2 after 6500C annealing, and the atomic ratio of Mo to Ti decreases from the top surface into Ti silicide film, and becomes zero at about 30 nm away from the surface. In both cases of interface Mo and surface Mo layer, the atomic ratio of Mo to Ti in the region of (Mo, Ti)Si2 was found to be very low, with an average value of less than 0.2. Low content of Mo in Mo containing ternary sili.zide leads easily to the formation of the stable phase of C54 (Mo, Ti)Si2, which acts as a templatc for the formation of C54 TiSi2 beneath when Mo is deposited on the surface.展开更多
基金Supported by Laboratory of Nuclear Analyses and Techniques,the Chinese Academy of Sciences
文摘Investigations on surface decomposition of GaN implanted with low energy (80 keV) Eu ion to a low dose (l×1014 cm-2), and its annealing behavior under high temperature (1050℃) in N2 are performed. The as-grown, as-implanted and annealed GaN films are characterized by proton elastic scattering (PES), Rutherford backscattering spectrometry (RBS), photoluminescence (PL) and atomic force microscopy (AFM). The results show that Eu ion implantation induces radiation defects and decomposition of GaN. The GaN surface decomposition is more serious during high temperature annealing. The atomic ratio of N in as-grown, as-implanted and annealed GaN film is 47 at.%, 44 at.% and 40 at.%, respectively. As a result, a rough Ga-rich layer is formed at the surface, though the lattice defects are partly removed after high temperature annealing.
基金Partly Supported by the National Nature Science Foundation of China (No. 19910131370)
文摘The effect of a 0.9 nm Mo interlayer at the interface of Ti film deposited on a Si substrate on phase formation of TiSi2 during annealing has been studied by using transmission electron micro-diffraction technique. When Ti/Mo/Si was an- nealed at low temperature as 550℃ for 30 mm in Ar ambient, a metastable phase. i.e., hexagonal C40 TiSi2, and the equilibrium phase. i.e., orthorhombic C54 TiSi2, were both detected. The experimental patterns of the C40 and C54 compare well with the simulated ones.
基金Supported Partly by the National Natural Science Foundation (No. 19910131370)
文摘Annealing behavior, at different annealing temperatures, of an ultrathin Mo layer located between a Ti film and Si substrate or deposited on the top of sur -face of a Ti film was investigated by Rutherford baccscattering spectrometry (RBS), cross-sectional transmission electron microscopy (TEM) and energy dispersive X-ray spectrometry (EDS). In a Ti/Mo/Si structure, partially reacted film with layer struc- ture of Ti-rich silicide/TiSi2/(Mo, Ti)Si2 on a Si substrate was formed after 550℃ annealing for 30 min. The ratio of Mo to Ti in (Mo, Ti)Si2 layer decreases from ncar Si substrate upwards and becomes zero at about 20 nm away. In a Mo/Ti/Si structure, the surface Mo layer enhances the Si diffusion from the substrate during annealing. Mo bearing Ti rich silicide exists on the surface until 600℃ and then converts to (Mo, Ti)Si2 after 6500C annealing, and the atomic ratio of Mo to Ti decreases from the top surface into Ti silicide film, and becomes zero at about 30 nm away from the surface. In both cases of interface Mo and surface Mo layer, the atomic ratio of Mo to Ti in the region of (Mo, Ti)Si2 was found to be very low, with an average value of less than 0.2. Low content of Mo in Mo containing ternary sili.zide leads easily to the formation of the stable phase of C54 (Mo, Ti)Si2, which acts as a templatc for the formation of C54 TiSi2 beneath when Mo is deposited on the surface.
