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Mechanical stability of reactive ion-etched poly (methylmethacrylate) and polyimide microstructures in trilevel electron beam lithography
Classified abstracts 5850 5861
plasm have been studied. It is shown that etch rates of resists exposed to doses greater than 1 × 10 ~5 cm 2 (1.6× 10 4 C cm Z)at40 k e V a r e m u c h smaller than those of unexposed resists. A differential etch rate as high as 11 is demonstrated. This property of ion beam inhibited etching (IBIE) has been used to fabricate resist structures with submicrometer features using 'see-through' thin silicon film masks. With further developments of high brightness ion sources, IB1E m a y be a useful technique to realize high resolution negative tone images in resists. J Adesida et al, d Vac Sci Technol, 21 (2), 1982, 666 -671. 35 5850. Laser-induced local heating of multilayers. (USA) For a multilayer structure illuminated by a laser beam, absorption of optical energy in the absorptive layers and the diffusion of the resultant heat throughout the structure are studied. Analytical and numerical procedures for this study are described, and, as a specific example, the profiles of temperature distribution during recording on a magnetooptical disc are presented. The technique is also expected to be of value for studies of thermal marking and laser annealing. Masud Mansuripur et al, Appl Optics, 21 (6), 1982, 1106 1114. 35
5851. Temperature dependence of the impact response of copper: erosion by melting. (GB)
demonstrated. This system enables an electric impulse energy as high as 2400 J for a target of 2 in. dia with a uniform illumination. Juh Tzeng Lue, Vacuum, 32 (12), 1982, 713 718. 35 5855. Electron beam induced heat flow transient in aluminium. (USA) O n the basis of a numerically solved heat diffusion equation, the structure of the thermal transient induced in an aluminium sample by an electron beam pulse is described in terms of slush zone formation, molten depth, liquid phase duration, and melt front history. The heat flow dynamics, as determined by monochromatic (electron energy ranging between 5 and 25 keV) and ultrashort (15 ns fwhm) pulses, is contrasted with the ruby laser induced one. Accessible absorbed energy intervals for sample surface melting are given as a function of electron energy; heating of the sample interior at values higher than those attained at the surface is shown to occur only at higher electron energies, for a given pulse duration. The general dependence of the present results on the pulse duration and the effects produced by polychromatic pulses are also discussed. (Italy) L F Donfi Dalle Rose el al, Rad E[lects, 69 (1/2), 1983, 1 17. 35
5856. EPR studies of the annealing of damage produced by boron implantation of silicon single crystals. (USA)
35
Electron paramegnetic resonance technique has been used to study the effect of boron implantation and subsequent annealing on silicon substrate. The mechanism explaining the physical nature of reverse annealing phenomenon is proposed. (Poland) T Gregorkiewicz, Rad E[]ects Letts, 68 (2), 1982, 69 76. 35 5857. Anomalous diffusion in phosphorus implanted silicon. (USA) Tailored phosphorus implanted emitters in p-type (100) oriented silicon single crystals obtained by superposition of 10 keV channelled implantation plus 40 keV random, show a dramatic enhancement of the dopant diffusion caused by the defects produced during implantation. Diffusion coefficients of the order of 5 x 1 0 ~4 and 5 x 1 0 13cm2s i were evaluated by annealing respectively at 6 5 0 C and 750'C in N 2 atmosphere. (Italy) R Galloni et al, Rad E[lbcts Letts, 68 (2), 1982, 39 44. 35
5852. A three-dimensional model for the transport properties of polycrystalline silicon.
5858. Physical problems concerning effusion processes of semiconductors in molecular beam epitaxy. (GB)
This work considered the transport properties of p-type polysilicon using a three-dimensional spherical model and compared the results with experimental data and a one-dimensional model commonly used. It was observed that the main differences between the two models exist after the crystal grains are totally depleted. This happens to be a region where reliable data (especially for carrier density) are scarce. From the theoretical analyses, the three-dimensional model seemed to be as good as the one-dimensional model in the high doping regime and for the resistivity data. Some significant differences existed between theory and experiment for the activation energies based on either of the two models and it is suspected that gross inhomogeneity could be the cause. (Hong Kong) H L K w o k a n d K H Ho, J P h y s D : A p p l P h y s , 1 5 ( l t ) , 1982, 2271 2281.
Equations for effusion of material in molecular beam epitaxy are presented for: (a) an effusion cell with a single thin wall orifice; (b) a single channel effusion cell and (c)a multichannel effusion cell. Multi-component systems GaAs AIGaAs and PbTe PbSnTe are discussed with emphasis on the stoichiometry of the films deposited. (Poland) Marian A Herman, Vacuum, 32 (9), 1982, 555 565. 35 5859. Ion beam techniques for material modification. (GB) A number of ion beam techniques for modifying the surface properties of solids are discussed. These include ion implantation, ion beam mixing, ion plating and recoil mixing. The physical processes involved in these techniques are outlined and applications are discussed including (i) the use of ion implantation to alter the friction and wear of copper surfaces, (ii) the use of ion beam mixing to form metallic glasses, Off) production of heat resistant and corrosion protective coatings by means of ion plating, and (iv) application of dynamic recoil mixing to the production of catalysts and photo-voltaic devices. W A Grant and J S Colligon, Vacuum, 32 (10/11), 1982, 675 683. 35
Annealed copper targets were impacted by 5 m m dia hardened steel spheres at a velocity of 130+20 m s ~ and at an impingement angle of 20+0.5'. Target temperatures were varied over the range 70 1350 K. Evidence for melting was found throughout the temperature range. At low temperatures melting was insufficient to produce detectable mass loss and was only found in localized shear bands. At temperatures within 200 K of homogeneous melting, mass losses as great as 0.8~,, of the impacting sphere were measured. In this latter range, evidence of considerable melting was observed in craters, and deposits of copper were found attached to the spheres. The deposits were composed of unusually small crystallites (grain size~ 10 ~tm) and appeared to have been formed by melting followed by rapid quenching. D R Andrews and J E Field, J Phys D: Appl Phys, 15 ( 11 ), 1982, 2357 2367.
35 5853. Characterisation of aluminium nitride layers formed directly by
700 8 0 0 keV ~5N~- implantation into aluminium. (GB) Accelerated 15N2~ ions were implanted into polycrystal and single-crystal AI sheets with fluences of 8 × 10 ~6 1.2 × 1018 N - cm - 2. The depth profiles of the implanted ~SN were measured by ~SN(p, ~,)~2C and 15N(p, %)~2C nuclear reactions. A change in the depth profile of the implanted tSN and significant recovery of the damaged A1 lattice were not observed even after annealing above 400' C over a wide range of implantation dose. In the case of low-dose implantation, channelling analysis combined with nuclear reaction analysis showed that the implanted ~SN was located near the tetrahedral interstitial site in the FCC AI lattice, while for high-dose hot implantation ordered structures were not observed. Direct evidence for AIN formation was obtained by ESCA. Measurements of electrical capacitance and dc resistance for the ~SN~-implanted AI sheets were also performed. (Japan) Yoshiaki Kido el al, J Phys D: Appl Phys, 15 (10), 1982, 2067 2077. 35
5854. A multichannei flash tube implemented for large area annealing of ion implanted semiconductors. (GB) A multichannel discharge flash tube implemented for large area processing of annealing and metallization of ion-implanted semiconductors is 238
5860. Mechanical stability of reactive ion-etched poly (methylmethaerylate) and polyimide mierostructures in trilevel electron beam lithography. (U SA ) Isolation layers are used in trilevel electron beam lithography to planarize wafer topography, reduce electron scattering effects, and increase the effective sensitivity and contrast of the lithographic process. The mechanical stability of the isolation layer structures may limit the overall resolution of the process. We have studied the resolution limits imposed by the mechanical stability of reactive ion-etched (methylmethacrylate) and polyimide isolation layer structures in trilevel electron beam lithography. We show that processes can be designed with 50 nm. James A Oro et al, d Appl Phys, 53 (11 ), 1982, 7379 7384. 35
5861. Preparation and properties of V~ubstituted garnet films for ionimplanted 1.0-micron bubble devices with improved high-temperature propagation. (USA) The growth and properties of films of a novel composition, (SmLuCa)3 (FeVSi)50~2, for 4/~m period lon-lmplanted Propagation Pattern devices, are described. The use of vanadium substitution to lower 4nM~
plasm have been studied. It is shown that etch rates of resists exposed to doses greater than 1 × 10 ~5 cm 2 (1.6× 10 4 C cm Z)at40 k e V a r e m u c h smaller than those of unexposed resists. A differential etch rate as high as 11 is demonstrated. This property of ion beam inhibited etching (IBIE) has been used to fabricate resist structures with submicrometer features using 'see-through' thin silicon film masks. With further developments of high brightness ion sources, IB1E m a y be a useful technique to realize high resolution negative tone images in resists. J Adesida et al, d Vac Sci Technol, 21 (2), 1982, 666 -671. 35 5850. Laser-induced local heating of multilayers. (USA) For a multilayer structure illuminated by a laser beam, absorption of optical energy in the absorptive layers and the diffusion of the resultant heat throughout the structure are studied. Analytical and numerical procedures for this study are described, and, as a specific example, the profiles of temperature distribution during recording on a magnetooptical disc are presented. The technique is also expected to be of value for studies of thermal marking and laser annealing. Masud Mansuripur et al, Appl Optics, 21 (6), 1982, 1106 1114. 35
5851. Temperature dependence of the impact response of copper: erosion by melting. (GB)
demonstrated. This system enables an electric impulse energy as high as 2400 J for a target of 2 in. dia with a uniform illumination. Juh Tzeng Lue, Vacuum, 32 (12), 1982, 713 718. 35 5855. Electron beam induced heat flow transient in aluminium. (USA) O n the basis of a numerically solved heat diffusion equation, the structure of the thermal transient induced in an aluminium sample by an electron beam pulse is described in terms of slush zone formation, molten depth, liquid phase duration, and melt front history. The heat flow dynamics, as determined by monochromatic (electron energy ranging between 5 and 25 keV) and ultrashort (15 ns fwhm) pulses, is contrasted with the ruby laser induced one. Accessible absorbed energy intervals for sample surface melting are given as a function of electron energy; heating of the sample interior at values higher than those attained at the surface is shown to occur only at higher electron energies, for a given pulse duration. The general dependence of the present results on the pulse duration and the effects produced by polychromatic pulses are also discussed. (Italy) L F Donfi Dalle Rose el al, Rad E[lects, 69 (1/2), 1983, 1 17. 35
5856. EPR studies of the annealing of damage produced by boron implantation of silicon single crystals. (USA)
35
Electron paramegnetic resonance technique has been used to study the effect of boron implantation and subsequent annealing on silicon substrate. The mechanism explaining the physical nature of reverse annealing phenomenon is proposed. (Poland) T Gregorkiewicz, Rad E[]ects Letts, 68 (2), 1982, 69 76. 35 5857. Anomalous diffusion in phosphorus implanted silicon. (USA) Tailored phosphorus implanted emitters in p-type (100) oriented silicon single crystals obtained by superposition of 10 keV channelled implantation plus 40 keV random, show a dramatic enhancement of the dopant diffusion caused by the defects produced during implantation. Diffusion coefficients of the order of 5 x 1 0 ~4 and 5 x 1 0 13cm2s i were evaluated by annealing respectively at 6 5 0 C and 750'C in N 2 atmosphere. (Italy) R Galloni et al, Rad E[lbcts Letts, 68 (2), 1982, 39 44. 35
5852. A three-dimensional model for the transport properties of polycrystalline silicon.
5858. Physical problems concerning effusion processes of semiconductors in molecular beam epitaxy. (GB)
This work considered the transport properties of p-type polysilicon using a three-dimensional spherical model and compared the results with experimental data and a one-dimensional model commonly used. It was observed that the main differences between the two models exist after the crystal grains are totally depleted. This happens to be a region where reliable data (especially for carrier density) are scarce. From the theoretical analyses, the three-dimensional model seemed to be as good as the one-dimensional model in the high doping regime and for the resistivity data. Some significant differences existed between theory and experiment for the activation energies based on either of the two models and it is suspected that gross inhomogeneity could be the cause. (Hong Kong) H L K w o k a n d K H Ho, J P h y s D : A p p l P h y s , 1 5 ( l t ) , 1982, 2271 2281.
Equations for effusion of material in molecular beam epitaxy are presented for: (a) an effusion cell with a single thin wall orifice; (b) a single channel effusion cell and (c)a multichannel effusion cell. Multi-component systems GaAs AIGaAs and PbTe PbSnTe are discussed with emphasis on the stoichiometry of the films deposited. (Poland) Marian A Herman, Vacuum, 32 (9), 1982, 555 565. 35 5859. Ion beam techniques for material modification. (GB) A number of ion beam techniques for modifying the surface properties of solids are discussed. These include ion implantation, ion beam mixing, ion plating and recoil mixing. The physical processes involved in these techniques are outlined and applications are discussed including (i) the use of ion implantation to alter the friction and wear of copper surfaces, (ii) the use of ion beam mixing to form metallic glasses, Off) production of heat resistant and corrosion protective coatings by means of ion plating, and (iv) application of dynamic recoil mixing to the production of catalysts and photo-voltaic devices. W A Grant and J S Colligon, Vacuum, 32 (10/11), 1982, 675 683. 35
Annealed copper targets were impacted by 5 m m dia hardened steel spheres at a velocity of 130+20 m s ~ and at an impingement angle of 20+0.5'. Target temperatures were varied over the range 70 1350 K. Evidence for melting was found throughout the temperature range. At low temperatures melting was insufficient to produce detectable mass loss and was only found in localized shear bands. At temperatures within 200 K of homogeneous melting, mass losses as great as 0.8~,, of the impacting sphere were measured. In this latter range, evidence of considerable melting was observed in craters, and deposits of copper were found attached to the spheres. The deposits were composed of unusually small crystallites (grain size~ 10 ~tm) and appeared to have been formed by melting followed by rapid quenching. D R Andrews and J E Field, J Phys D: Appl Phys, 15 ( 11 ), 1982, 2357 2367.
35 5853. Characterisation of aluminium nitride layers formed directly by
700 8 0 0 keV ~5N~- implantation into aluminium. (GB) Accelerated 15N2~ ions were implanted into polycrystal and single-crystal AI sheets with fluences of 8 × 10 ~6 1.2 × 1018 N - cm - 2. The depth profiles of the implanted ~SN were measured by ~SN(p, ~,)~2C and 15N(p, %)~2C nuclear reactions. A change in the depth profile of the implanted tSN and significant recovery of the damaged A1 lattice were not observed even after annealing above 400' C over a wide range of implantation dose. In the case of low-dose implantation, channelling analysis combined with nuclear reaction analysis showed that the implanted ~SN was located near the tetrahedral interstitial site in the FCC AI lattice, while for high-dose hot implantation ordered structures were not observed. Direct evidence for AIN formation was obtained by ESCA. Measurements of electrical capacitance and dc resistance for the ~SN~-implanted AI sheets were also performed. (Japan) Yoshiaki Kido el al, J Phys D: Appl Phys, 15 (10), 1982, 2067 2077. 35
5854. A multichannei flash tube implemented for large area annealing of ion implanted semiconductors. (GB) A multichannel discharge flash tube implemented for large area processing of annealing and metallization of ion-implanted semiconductors is 238
5860. Mechanical stability of reactive ion-etched poly (methylmethaerylate) and polyimide mierostructures in trilevel electron beam lithography. (U SA ) Isolation layers are used in trilevel electron beam lithography to planarize wafer topography, reduce electron scattering effects, and increase the effective sensitivity and contrast of the lithographic process. The mechanical stability of the isolation layer structures may limit the overall resolution of the process. We have studied the resolution limits imposed by the mechanical stability of reactive ion-etched (methylmethacrylate) and polyimide isolation layer structures in trilevel electron beam lithography. We show that processes can be designed with 50 nm. James A Oro et al, d Appl Phys, 53 (11 ), 1982, 7379 7384. 35
5861. Preparation and properties of V~ubstituted garnet films for ionimplanted 1.0-micron bubble devices with improved high-temperature propagation. (USA) The growth and properties of films of a novel composition, (SmLuCa)3 (FeVSi)50~2, for 4/~m period lon-lmplanted Propagation Pattern devices, are described. The use of vanadium substitution to lower 4nM~