Browsing by Author "Luo, JS"

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Annealing effects on the interfacial reactions of Ni on Si0.76Ge0.24 and Si1-x-yGexCy
(2000-01-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
;
Pan, FM
Interfacial reactions of Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy by vacuum annealing and pulsed KrF laser annealing were studied. Upon annealing at a temperature of 200-600 degrees C Ge segregation occurred with the extent becoming more severe at higher temperatures. The temperatures at which phase transformation and the agglomeration structure occurred were higher for Ni/Si1-x-yGexCy than for Ni/Si0.76Ge0.24. Upon pulsed KrF laser annealing the agglomeration structure was considerably improved, however, the retardation of phase transformation in the Ni/Si1-x-yGexCy system still occurred. C accumulation around the original amorphous/crystal interface formed by Cf implantation played a significant effect on delaying the phase transformation. For the Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy samples annealed at 0.2 J/cm(2) for 20 and 30 pulses, respectively, smooth Ni(Si0.76Ge0.24)(2) and Ni(Si1-x-yGexCy)(2) films could be grown, meanwhile Ge segregation and strain relaxation of the unreacted Si0.76Ge0.23 films were effectively suppressed. (C) 2000 American Vacuum Society. [S0734-2101(00)04301-3].
Characterization of Si1-x-yGexCy films grown by C+ implantation and subsequent pulsed laser annealing
(1999-07-15)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
;
Pan, FM
Epitaxial Si1-x-yGexCy films have been grown by C+ implantation into Si0.76Ge0.24 films with a dose of 1.0 x 10(16)/cm(2) and subsequent pulsed KrF laser annealing at an energy density of 0.3-1.6 J/cm(2). Upon laser annealing Ce segregation to the film surface and diffusion to the underlying Si appeared at energy densities above 0.8 J/cm(2) and 1.4 J/cm(2), respectively while the depth profiles of C remained nearly unchanged as in the as-implanted Si1-x-yGeyCy film. Concurrently, no SiC and twin were observed. The amount of C incorporated into substitutional sites initially increased with the energy density in the range of 0.3-1.0 J/cm(2), and then saturated at an energy density of 1.0-1.6 J/cm(2). For the Si1-x-yGexCy films grown at 1.0 J/cm(2) for 5 and 20 pulses SiC was formed with its amount increasing with the pulse number because of C segregation to the film surface and the original amorphous/crystal interface where the EOR defects were present. For the Si1-x-yGexCy films grown at energy densities below 1.0 J/cm(2) the reduction of tensile stress mainly resulted from the effect of substitutional carbon incorporation. (C) 1999 Elsevier Science S.A. All rights reserved.
Effects of an interposed Mo layer on the interfacial reactions of Ti/Si0.76Ge0.24 by rapid thermal annealing and pulsed laser annealing
(2000-10-01)
Huang, JC
;
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
The thickness effect of an interposed Mo layer between Ti and Si0.76Ge0.24 films on the lowering of the formation temperature of C54 (Ti, Mo)(Si1-xGex)(2), thereby reducing Ge segregation and agglomeration of the C54 (Ti, Mo)(Si1-xGex)(2) films, is studied. Upon rapid thermal annealing, the interposed Mo layer can significantly reduce the formation temperature of C54 (Ti, Mo)(Si1-xGex)(2); however, the amount of reduction decreases with the Mo thickness. The electron/atom ratio seems to be one of the important factors in the lowering of the formation temperature of C54 (Ti, Mo)(Si1-xGex)(2). For the samples having an interposed Mo layer 0.5 nm thick a smooth C54 (Ti, Mo)(Si1-xGex)(2) film without Ge segregation can be grown after annealing at a temperature of 625-650 degreesC. For pulsed KrF laser annealing the rapid melt/solidification process allows only growth of C40 Ti(Si1-xGex)(2) or C40 (Ti, Mo)(Si1-xGex)(2) even though an interposed Mo layer is introduced into the Ti/Si0.76Ge0.24 samples, indicating that upon pulsed laser annealing the kinetic effect can dominate over the thermodynamic effect.
Effects of Mo-free C40Ti(Si1-xGex)(2) precursors and the thickness of an interposed Mo layer on the enhanced formation of C54Ti(Si1-xGex)(2)
(1999-11-29)
Luo, JS
;
Huang, JC
;
Lin, WT
;
Chang, CY
;
Shih, PS
The effects of Mo-free C40 Ti(Si1-xGex)(2) precursors and the thickness of an interposed Mo layer between Ti films and Si0.76Ge0.24 substrates on the lowering of formation temperature of C54 Ti(Si1-xGex)(2) were studied. Metastable C40 Ti(Si1-xGex)(2) precursors were grown by pulsed KrF laser annealing. Upon rapid thermal annealing, the Mo-free C40 phase could not be directly transformed to the C54 phase without going through the C49 phase. When the thickness of the interposed Mo layer increased, up to 2.5 nm, the temperature at which the C54 phase was initially formed changed from 750 to 600 and then to 650 degrees C. The present result showed that with increasing Mo concentration in the reacted layer, the phase stability shifted from C54 to C40 and no C49 was observed. It seems that apart from the C40 template mechanism, the electron/atom ratio also plays an important role in the enhanced formation of the C54 phase. (C) 1999 American Institute of Physics. [S0003-6951(99)02048-3].
Interfacial reactions of Co/Si0.76Ge0.24 and Co(Si0.76Ge0.24)/Si0.76Ge0.24 by pulsed KrF laser annealing
(1999-08-01)
Luo, JS
;
Hang, YL
;
Lin, WT
;
Chang, CY
;
Shih, PS
Interfacial reactions of Co/Si0.76Ge0.24 and Co(Si0.76Ge0.24)/Si0.76Ge0.24 by pulsed KrF laser annealing as a function of energy density and pulse number were studied. For the Co/Si0.76Ge0.24 samples annealed at an energy density of 0.2-0.6 J/cm(2), three germanosilicide layers, i.e., amorphous structure and/or nanocrystal, Co(Si1-xGex), and Co(Si1-xGex)(2), were successively formed along the film-depth direction. At 0.3 J/cm(2) Ge segregated to the underlying Si0.76Ge0.24 film, inducing strain relaxation in the residual Si0.76Ge0.24 film. At 0.8 J/cm(2) the reacted region was mostly transformed to a single layer of Co(Si1-xGex)(2), whereas Ge further diffused to the Si substrate. At 1.0 J/cm2, constitutional supercooling appeared. Even the Co(Si0.76Ge0.24) film used as the starting material for laser annealing could not prevent the occurrence of constitutional supercooling at energy densities >1.6 J/cm2. The energy densities at which Co(Si1-xGex) transformation to Co(Si1-xGex)(2), Ge segregation to the underlying Si, and constitutional supercooling occurred were higher for the Co(Si0.76Ge0.24)/Si0.76Ge0.24 system than for the Co/Si0.76Ge0.24 system. Higher energy density and/or pulse number enhanced the growth of Co(Si,,Ge,), film. In the present study, the Co/Si0.76Ge0.24 samples subjected to annealing at 0.2 J/cm(2) for 20 pulses produced a smooth Co(Si,,,Ge,,,), film without inducing Ge segregation out of the germanosilicide and strain relaxation in the unreacted Si0.76Ge0.24 film.
Interfacial reactions of Ni on Si0.76Ge0.24 and Si by pulsed laser annealing
(1998-07-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Tsai, WC
;
電子工程學系及電子研究所
Pulsed KrF laser annealing and vacuum annealing on the interfacial reactions of Ni/Si0.76Ge0.24 and Ni/Si were studied. For the Ni/ Si0.76Ge0.24 films annealed at temperatures above 300 degrees C, some Ge-rich Si1-xGex grains were formed between the Ge-deficient Ni germanosilicide grains, resulting in the island structure. For Ni/Si films homogeneous epitaxial NiSi2 films could be grown even at 600 degrees C. Ni silicide (germanosilicide) associated with the amorphous overlayer was generally formed at lower energy densities for Ni/Si, NiSi/Si, Ni/Si0.76Ge0.24 and Ni(Si1-xGex) /Si0.76Ge0.24 systems, respectively. At higher energy densities constitutional supercooling occurred. The energy densities at which constitutional supercooling appeared were higher for NiSi and Ni(Si1-xGex) than for Ni. For the continuous Ni(Si1-xGex) films grown at 200 degrees C in a vacuum furnace, subsequent laser annealing at an energy density of 0.6-1.0 J cm(-2) have shown to render homogeneous Ni(Si0.76Ge0.24)(2) and Si0.76Ge0.24 films without the island structure and Ge segregation. (C) 1998 Elsevier Science S.A. All rights reserved.
Interfacial reactions of Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy by vacuum annealing and pulsed KrF laser annealing
(2000-06-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
;
電子工程學系及電子研究所
Interfacial reactions of Ni on Si0.76Ge0.24 and Si1-x-yGexCy. films by vacuum annealing and pulsed KrF laser annealing were studied by transmission electron microscopy (TEM) in conjunction with energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). For the Ni/Si0.76Ge0.24 and Ni/Si1-x-yGexCy films annealed at a temperature of 200-600 degrees C Ge segregation and agglomeration occurred at an extent becoming more severe at higher temperatures. Upon pulsed KrF laser annealing the agglomeration structure was improved. The retardation of phase transformation in the Ni/Si1-x-yGexCy system was observed upon either vacuum annealing or pulsed laser annealing. Multiple-pulse annealing is an effective method to fabricate smooth Ni(Si0.76Ge0.24)(2) and Ni(Si1-x-yGexCy)(2) films without inducing Ge segregation to the remaining substrates and strain relaxation. (C) 2000 Elsevier Science B.V. All rights reserved.
Interfacial reactions of Pd/Si0.76Ge0.24 by pulsed KrF laser annealing
(1998-09-07)
Chen, DR
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Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
The interfacial reactions of Pd/Si0.76Ge0.24 were studied by pulsed KrF laser annealing as a function of energy density and pulse number. At an energy density of 0.1-0.4 J/cm(2), a continuous germanosilicide layer composed of a low-temperature phase, Pd-2(Si1-xGex), and a high-temperature phase, Pd(Si1-xGex), was formed. Incontrast to vacuum annealing, Ge segregation out of the germanosilicide layer and the strain relaxation of the residual Si0.76Ge0.24 film could be effectively suppressed by pulsed KrF laser annealing at 0.1 J/cm(2). Multiple pulse annealing at 0.1 J/cm(2) could further homogenize the Pd concentration of the germanosilicide layer and promote the growth of Pd(Si1-xGex). Concurrently, the smoothness of the germanosilicide layer was substantially improved in comparison with those grown by vacuum annealing at temperatures above 200 degrees C. The studies also revealed that for multiple pulse annealing at 0.1 J/cm(2) with a low repetition rate, 1 Hz, the evolution of phase formation and Pd diffusion could be proceeded by each individual laser pulse. (C) 1998 American Institute of Physics. [S0003-6951(98)04136-9].
Interfacial reactions of the Co/Si1-xGex system
(1997-04-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Tsai, WC
;
Wang, SJ
Thermal reactions of Co(200 Angstrom)/Si0.76Ge0.24(1500 Angstrom)/Si and Co(200 Angstrom)/Si0.54Ge0.46(1000 Angstrom)/Si systems in a vacuum of 1-2 X 10(-6) Ton. were studied. At temperatures above 200 degrees C Ge segregation appeared even though no silicides and/or germanosilicides were formed. At a temperature of 225-550 degrees C Co(Si1-yGey) was formed, in which the Ge concentration was deficient, The formation temperatures of CoSi2 in the Co/Si1-xGex systems, where x = 0.24 and 0.46, were above 575 degrees C, being relatively higher than that in the Co/Si system. At temperatures above 500 degrees C the island structure, Ge segregation to the surface of the exposed Si1-xGex films, and the penetration of reacted layer into the Si substrate occurred, At temperatures above 700 degrees C a SiC layer was grown on the film surface. For the Si0.54Ge0.46 films the penetration of the reacted layer into the Si substrate occurred even at 350 degrees C owing to the wave structure of the as-grown Si0.54Ge0.46 films. A Si layer interposed between Co and Si0.76Ge0.24 films is an effective scheme to grow a continuous CoSi, contact at 550-600 degrees C without inducing Ge segregation and hence the strain relaxation in the Si0.76Ge0.24 films.
Pulsed KrF laser annealing of Mo/Si0.76Ge0.24
(2000-06-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
;
Chang, TC
Interfacial reactions of Mo/Si0.76Ge0.24 were studied by pulsed KrF laser annealing as a function of the energy density and pulse number. Vacuum annealing was also performed on some samples for comparison. For the samples annealed at a temperature of 500-700 degrees C a continuous hexagonal Mo(Si1-xGex)(2) (h-Mo(Si1-xGex)(2)) film was formed, while Ge segregation from the h-Mo(Si1-xGex)(2) film to the underlying Si0.76Ge0.24 occurred with the extent becoming more severe at higher annealing temperatures. Concurrently, amorphous structures appeared in the Si0.76Ge0.24 substrate. At 700 degrees C h-Mo(Si1-xGex)(2) transformed to tetragonal Mo(Si1-xGex)(2) (t-Mo(Si1-xGex)(2)). Multiple-pulse laser annealing could produce a continuous h-Mo(Si1-xGex)(2) film without forming amorphous structures in the Si0.76Ge0.24 substrate, however, it could not suppress Ge segregation. In the present study, no t-Mo(Si1-xGex)(2) was formed upon pulsed KrF laser annealing even at higher energy densities. (C) 2000 Elsevier Science B.V. All rights reserved.
Pulsed KrF laser annealing of Ni/Si0.76Ge0.24 films
(1997-10-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Tsai, WC
;
電子工程學系及電子研究所
Pulsed KrF laser annealing can suppress the island structure formation and Ge segregation associated with the interfacial reactions of Ni/Si0.76Ge0.24 For the Ni/Si0.76Ge0.24 films annealed at an energy density of 0.1-0.3 J/cm(2) nickel germanosilicide associated with the amorphous overlayer was formed, while at energy densities above 0.4 J/cm(2) cellular structures of Ge-deficient S1-xGex islands surrounded by Ni(Si1-xGex)(2) due to the constitutional supercooling occurred. For the continuous Ni(Si1-xGex) films grown at 200 degrees C, subsequent laser annealing at a higher energy density of 0.6-1.0 J/cm(2) caused transformation into homogeneous Ni(Si0.76Ge0.24)(2) films without island structure and Ge deficiency which readily appeared on furnace annealing at temperatures above 400 degrees C. At energy densities above 1.6 J/cm(2) the same cellular structures as described above were also noted. (C) 1997 American Institute of Physics.
Pulsed KrF laser annealing of Ni/Si0.76Ge0.24 films
(1997-10-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Tsai, WC
;
電子工程學系及電子研究所
Pulsed KrF laser annealing can suppress the island structure formation and Ge segregation associated with the interfacial reactions of Ni/Si0.76Ge0.24 For the Ni/Si0.76Ge0.24 films annealed at an energy density of 0.1-0.3 J/cm(2) nickel germanosilicide associated with the amorphous overlayer was formed, while at energy densities above 0.4 J/cm(2) cellular structures of Ge-deficient S1-xGex islands surrounded by Ni(Si1-xGex)(2) due to the constitutional supercooling occurred. For the continuous Ni(Si1-xGex) films grown at 200 degrees C, subsequent laser annealing at a higher energy density of 0.6-1.0 J/cm(2) caused transformation into homogeneous Ni(Si0.76Ge0.24)(2) films without island structure and Ge deficiency which readily appeared on furnace annealing at temperatures above 400 degrees C. At energy densities above 1.6 J/cm(2) the same cellular structures as described above were also noted. (C) 1997 American Institute of Physics.
Room temperature oxidation of Cu/Si0.76Ge0.24 annealed at 200 to 300 degrees C
(1999-06-01)
Luo, JS
;
Lin, WT
;
Chang, CY
;
Shih, PS
;
電子工程學系及電子研究所
The Cu3Si-catalyzed oxidation behavior of Cu/Si0.76Ge0.24 after annealing at a temperature of 200-300 degrees C was studied using transmission electron microscopy (TEM). For the Cu/Si0.76Ge0.24 samples annealed at 200 degrees C and followed by exposure in air for 1-4 weeks an SiO2 layer embedded with precipitates containing Cu, Ge, Si, and O was formed on the surface of the Cu-3(Si1-xGex) film. During exposure the Cu atoms released from Cu-3(Si1-xGex) by oxidation diffused down to the residual Si0.76Ge0.24 film and subsequently the Si substrate to form. new Cu-3(Si1-xGex) and Cu3Si, respectively. After exposure for 5-6 weeks not only the oxidation of the surface layer became severe but also the growth of the buried SiO2 layer was initiated at the Cu-3(Si1-xGex)/Cu3Si interface. Concurrently, the Cu3Si-catalyzed oxidation of Si by inward movement of the SiO2/Si interface was also observed. As compared with the annealed Cu/Si samples the presence of Ge significantly lowered the oxidation rate of the annealed Cu/Si0.76Ge0.24 samples. Higher temperature annealing promoted the oxidation rate because of Ge segregation out of the Cu-3(Si1-xGex) layer and the formation of a larger fraction of the Cu-3(Si1-xGex)/Cu3Si interface where the buried SiO2 layer was initially formed. (C) 1999 Elsevier Science S.A. All rights reserved.