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Molecular beam epitaxy
World Abstracts on Microelectronics and Reliability 9. E L E C T R O N ,
ION
Molecular beam epitaxy, MORTONG. PANISHand ALFREDY. CHO. IEEE Spectrum. 18 (April 1980). After years of" research, molecular beam epitaxy (MBE), a process for forming thin, single-crystal semiconductor structures in an ultrahigh vacuum, is beginning to pay dividends. Microwave field-effect transistors, semiconductor lasers, millimeterwave detectors, and a variety of other high-performance devices have been made from the multilayer crystals grown by the process. A greater variety of devices and still higher performance can be expected.
Piezoresistance tensor coefficients of phosphorus implanted silicon thin films. JANUSZ RYnlNSKL Electron Technol. 12, (2) 59 (1979). High resistivity p-type silicon has been implanted with phosphorus ions of 70keV energy, at doses from 1017 up to 1019ions/m 2. Piezoresistance longitudinal gauge factors in 1-100] and [H1] directions has been measured within the temperature range from - 80°C to 120°C. Piezoresistance tensor factors as a function of the implanted ions dose have been calculated from the above measurements. Photoexcitation effects during laser trimming of thin-film resistors on silicon. AMI KESTENBAUMand THOMASF. BAER. IEEE Trans. Components, Hybrids Mfg Technol. Chmt-3, (1) 166 (March 1980). Laser trimming of thin films on silicon is normally done with a Q-switched yttrium aluminum garnet (YAG) laser. Pulses from such a laser consist of photons which are sufficiently energetic to create electron-hole pairs in the silicon. The excess carriers created by the laser may then alter the electrical behavior of silicon devices which are in proximity to the thin films. An integrated circuit amplifier chip was used to investigate laser-induced photoexcitation effects on various silicon devices. For silicon resistors substantial conductivity modulation was observed under laser illumination. For active devices laser ligl~t alters the electrical characteristics for the duration of the effect. In all cases, excess carrier recombination occurred in several tens of microseconds--a period much shorter than the normal interval between laser pulses. Based on this investigation it is clear that in trimming, active devices tracking techniques (whereby parameters are continuously monitored) cannot be used. Measure and predict routines must be developed for trimming active thin film on silicon devices. However, when employing these routines, delay times necessary to eliminate photoexcitation effects are likely to be much shorter than the actual measurement times, so that the effect should not lengthen trimming times.
Ionization assisted annealing of boron implanted silicon. HENRYK RZEWUSKI, JAN SUSKI and JANUSZ KRYNICKI. Electron Technol. 12, (2) 67 (1979). Annealing, in the dark
AND
LASER
917
BEAMS
and under an ionization background of a 100keV electron beam of intensity 7.5 #A/cm 2 and the UV light of a 250 W mercury lamp, was studied in silicon samples implanted at room temperature with doses 3.101s-2 '1015 of boron ions/cm 2, in the temperature range 40(~900°C. Compared to thermal annealing in the dark, no change of the annealing course in the range 400-550°C is observed. At higher . temperature ranges 550-650°C and 650-900°C the radiation annealing curve is shifted towards higher temperatures by an amount which depends on the dose of implanted boron ions. The activation energies obtained from isothermal annealing runs have higher values for the ionization background. A tentative interpretation attributes the retardment of the annealing processes to the charge-state modification of defects undergoing transformations induced by ionizing radiation.
Ion beams promise practical systems for submicrometer wafer lithography. ROBERT L. SELIC3ER ,and PAUL A. SULLIVAN. Electronics. 142 (27 March 1980). Focused and masked techniques could compete with scanning E-beam and X-ray methods, respectively. A study of PtSi formation. DANUTA BRZEZINSKA and MICHEL ZABOROWSKI. Electron Technol. 12, (2) 93 (1979). The paper presents the problems associated with the formation and examination of platinum silicide thin films. PtSi was obtained by deposition of ion sputtered Pt on Si substrates, followed by annealing at 450°C and 600°C. The effect of sputter cleaning of Si substrates prior to Pt deposition was studied. The method of chemical preparation is outlined and the effect of the atmosphere of annealing on PtSi formation is discussed. It is proposed to use a second, oxidixing annealing to make PtSi resistant against chemical attack of Pt etching solution. The backscattering method as applied to thin film investigations is presented. The diffusion coefficient of Si in PtSi is calculated and found to be D = 2 . 1 . 1 0 - 1 6 m 2s-1. The results of microscopic examination are also presented.
Thin layer high-voltage devices (resurf devices). J. A. APPE~, M. G. COLLET, P. A. H. HART, H. M. J. VAESand J. F. C. M. VERHOEVEN. Philips J. Res. 35, (1) 1 (1980). The application of thin epitaxial or implanted layers in high-voltage devices is described. By means of these layers the applied reverse voltage is laterally equally distributed along the surface. In this way it is possible to make high-voltage devices even with relatively thin layers. Because of the fact that, compared with conventional devices, crucial changes in the electric field distribution take place at or at least near the surface, the acronym RESURF was chosen, which stands for REduced SURface Field.
ION
Molecular beam epitaxy, MORTONG. PANISHand ALFREDY. CHO. IEEE Spectrum. 18 (April 1980). After years of" research, molecular beam epitaxy (MBE), a process for forming thin, single-crystal semiconductor structures in an ultrahigh vacuum, is beginning to pay dividends. Microwave field-effect transistors, semiconductor lasers, millimeterwave detectors, and a variety of other high-performance devices have been made from the multilayer crystals grown by the process. A greater variety of devices and still higher performance can be expected.
Piezoresistance tensor coefficients of phosphorus implanted silicon thin films. JANUSZ RYnlNSKL Electron Technol. 12, (2) 59 (1979). High resistivity p-type silicon has been implanted with phosphorus ions of 70keV energy, at doses from 1017 up to 1019ions/m 2. Piezoresistance longitudinal gauge factors in 1-100] and [H1] directions has been measured within the temperature range from - 80°C to 120°C. Piezoresistance tensor factors as a function of the implanted ions dose have been calculated from the above measurements. Photoexcitation effects during laser trimming of thin-film resistors on silicon. AMI KESTENBAUMand THOMASF. BAER. IEEE Trans. Components, Hybrids Mfg Technol. Chmt-3, (1) 166 (March 1980). Laser trimming of thin films on silicon is normally done with a Q-switched yttrium aluminum garnet (YAG) laser. Pulses from such a laser consist of photons which are sufficiently energetic to create electron-hole pairs in the silicon. The excess carriers created by the laser may then alter the electrical behavior of silicon devices which are in proximity to the thin films. An integrated circuit amplifier chip was used to investigate laser-induced photoexcitation effects on various silicon devices. For silicon resistors substantial conductivity modulation was observed under laser illumination. For active devices laser ligl~t alters the electrical characteristics for the duration of the effect. In all cases, excess carrier recombination occurred in several tens of microseconds--a period much shorter than the normal interval between laser pulses. Based on this investigation it is clear that in trimming, active devices tracking techniques (whereby parameters are continuously monitored) cannot be used. Measure and predict routines must be developed for trimming active thin film on silicon devices. However, when employing these routines, delay times necessary to eliminate photoexcitation effects are likely to be much shorter than the actual measurement times, so that the effect should not lengthen trimming times.
Ionization assisted annealing of boron implanted silicon. HENRYK RZEWUSKI, JAN SUSKI and JANUSZ KRYNICKI. Electron Technol. 12, (2) 67 (1979). Annealing, in the dark
AND
LASER
917
BEAMS
and under an ionization background of a 100keV electron beam of intensity 7.5 #A/cm 2 and the UV light of a 250 W mercury lamp, was studied in silicon samples implanted at room temperature with doses 3.101s-2 '1015 of boron ions/cm 2, in the temperature range 40(~900°C. Compared to thermal annealing in the dark, no change of the annealing course in the range 400-550°C is observed. At higher . temperature ranges 550-650°C and 650-900°C the radiation annealing curve is shifted towards higher temperatures by an amount which depends on the dose of implanted boron ions. The activation energies obtained from isothermal annealing runs have higher values for the ionization background. A tentative interpretation attributes the retardment of the annealing processes to the charge-state modification of defects undergoing transformations induced by ionizing radiation.
Ion beams promise practical systems for submicrometer wafer lithography. ROBERT L. SELIC3ER ,and PAUL A. SULLIVAN. Electronics. 142 (27 March 1980). Focused and masked techniques could compete with scanning E-beam and X-ray methods, respectively. A study of PtSi formation. DANUTA BRZEZINSKA and MICHEL ZABOROWSKI. Electron Technol. 12, (2) 93 (1979). The paper presents the problems associated with the formation and examination of platinum silicide thin films. PtSi was obtained by deposition of ion sputtered Pt on Si substrates, followed by annealing at 450°C and 600°C. The effect of sputter cleaning of Si substrates prior to Pt deposition was studied. The method of chemical preparation is outlined and the effect of the atmosphere of annealing on PtSi formation is discussed. It is proposed to use a second, oxidixing annealing to make PtSi resistant against chemical attack of Pt etching solution. The backscattering method as applied to thin film investigations is presented. The diffusion coefficient of Si in PtSi is calculated and found to be D = 2 . 1 . 1 0 - 1 6 m 2s-1. The results of microscopic examination are also presented.
Thin layer high-voltage devices (resurf devices). J. A. APPE~, M. G. COLLET, P. A. H. HART, H. M. J. VAESand J. F. C. M. VERHOEVEN. Philips J. Res. 35, (1) 1 (1980). The application of thin epitaxial or implanted layers in high-voltage devices is described. By means of these layers the applied reverse voltage is laterally equally distributed along the surface. In this way it is possible to make high-voltage devices even with relatively thin layers. Because of the fact that, compared with conventional devices, crucial changes in the electric field distribution take place at or at least near the surface, the acronym RESURF was chosen, which stands for REduced SURface Field.