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RBS and SIMS measurements of the fluence dependence of the range distributions of Pb implanted into Si(111) crystals
Vacuum/volume 34lnumber Printed in Great Britain
1 O/l 1 /pages 1021 to 1023/l
0042-207X/84$3.00 + .OO Pergamon Press Ltd
984
Abstracts Optical furnace annealing of high and low dose silicon ion implanted GaAs N J Barrett, D C Bartle and J D Grange, GEC Research Laboratories, Hirst Research Centre, Wembley, Middx, UK
Selective area ion implantation is one means of fabricating planar GaAs ICs. In many circuit applications it is imperative that high dopant activation efficiencies are achieved for both low and high dose implants. In this paper we present results of post implantation annealing of *‘Si+ implanted GaAs using an 18 kW optical furnace. The design and construction of which will be fully discussed. Silicon is amphoteric, tending to occupy arsenic lattice sites above 880°C creating either p-type activation or neutral complexes. To obtain good electrical activation with high doses, temperatures > 880°C are required. The time taken to reach a maximum sheet carrier concentration at a particular temperature is dose dependent. Consequently low implant doses (- 5 x 10” cm-‘) are activated before high doses (- 1 x lOI cm-*). In this high temperature regime (> SSOC), as the high implanted dose is being electrically activated a lower dose (implanted into the same GaAs wafer) may have reached a maximum activation and started to decrease in electrical activation because of the amphoteric behaviour of silicon. Precisely controlled annealing conditions using short heating periods with rapid rise times (>2Oo”C s- ‘) are required to simultaneously maximize the activation of high and low doses of Si implants. This has been achieved using the novel annealing technique of thermal pulse annealing using an optical furnace. Acknowledgement
This work has been carried out with the support of the Procurement Executive, Ministry of Defence. sponsored by DCVD.
Static SIMS, FABMS and SlMS imaging for surface analysis of technologically important materials A Brown and J C Vickerman, UMIST Sut-fbchce Analysis lndustrial Unit, Department of Chemistry, UMIST, Sackrille Street, Manchester M60 lQD, UK
Static secondary ion mass spectrometry (SIMS) and fast atom bombardment mass spectrometry (FABMS) are of considerable importance as techniques for chemical characterization of surfaces. A mass spectrum of the surface layer provides not only compositional analysis from the elemental ions, but also chemical structure analysis from the cluster ions. Thus the chemical state of the surface is accessible in much the same way as the chemistry of an organic compound can be studied by organic mass spectrometry.
Recent advances in ion gun technology, utilizing liquid metal sources with beam diameters of < 1 pm provide the possibility of mapping the surface chemistry with a high degree of spatial resolution. This paper describes the application of SIMS imaging to ,a number of applied surface problems using a liquid gallium source. The experimental parameters and problems are described and discussed. In particular, since a large proportion of materials of practical interest are insulators, the procedures developed to permit the acquisition of spectra from such solids are outlined. Three main areas of application have been explored and are described: first, catalyst characterization where the chemical state and dispersion of active material has been monitored at the catalyst support surface; second, the characterization of optical coatings on glass; and third, studies of the chemistry of interfaces and dopants of InP device materials.
RBS and SIMS measurements of the fluence dependence of the range distributions of Pb implanted into Si( 111) crystals S Kostic, J J Jimenez-Rodriguez* and D G Armour, Department of Electronic and Electrical Engineering, Uniaersit) of Salford, Saljbrd M5 4 WT, UK
Rutherford backscattering measurements of the range distributions of Pb implanted into Si have consistently indicated a build up of Pb close to the surface at high fluences. This effect, which is associated with either segregation or range shortening (or a combination of both processes), has been investigated in detail using RBS and SIMS measurements of the depth profiles of Pb implanted into Si with fluences in the range 5 x 1O14m7.5xlOI cm-‘. The results obtained using the two analytical techniques are compared with theoretical prediction and the reasons for the fluence dependence of the range profiles are discussed.
* Department of Electricity and Electronics, Faculty of Physical Science, University of Madrid, Madrid 3, Spain.
Two-dimensional interfaces
electron gas systems at semiconductor
A C Cossard, A T & T Bell Laboratories, Murray Hill, Nebc Jersey 07974, USA
The heterointerface between epitaxial layers of dissimilar semiconductors forms a useful locusfor confinement of electrons to two-dimensional motion. Electrons with high mobilities and long scattering times may be introduced by modulation doping and display strong magneto quantum effects including the quantum 1021
1 O/l 1 /pages 1021 to 1023/l
0042-207X/84$3.00 + .OO Pergamon Press Ltd
984
Abstracts Optical furnace annealing of high and low dose silicon ion implanted GaAs N J Barrett, D C Bartle and J D Grange, GEC Research Laboratories, Hirst Research Centre, Wembley, Middx, UK
Selective area ion implantation is one means of fabricating planar GaAs ICs. In many circuit applications it is imperative that high dopant activation efficiencies are achieved for both low and high dose implants. In this paper we present results of post implantation annealing of *‘Si+ implanted GaAs using an 18 kW optical furnace. The design and construction of which will be fully discussed. Silicon is amphoteric, tending to occupy arsenic lattice sites above 880°C creating either p-type activation or neutral complexes. To obtain good electrical activation with high doses, temperatures > 880°C are required. The time taken to reach a maximum sheet carrier concentration at a particular temperature is dose dependent. Consequently low implant doses (- 5 x 10” cm-‘) are activated before high doses (- 1 x lOI cm-*). In this high temperature regime (> SSOC), as the high implanted dose is being electrically activated a lower dose (implanted into the same GaAs wafer) may have reached a maximum activation and started to decrease in electrical activation because of the amphoteric behaviour of silicon. Precisely controlled annealing conditions using short heating periods with rapid rise times (>2Oo”C s- ‘) are required to simultaneously maximize the activation of high and low doses of Si implants. This has been achieved using the novel annealing technique of thermal pulse annealing using an optical furnace. Acknowledgement
This work has been carried out with the support of the Procurement Executive, Ministry of Defence. sponsored by DCVD.
Static SIMS, FABMS and SlMS imaging for surface analysis of technologically important materials A Brown and J C Vickerman, UMIST Sut-fbchce Analysis lndustrial Unit, Department of Chemistry, UMIST, Sackrille Street, Manchester M60 lQD, UK
Static secondary ion mass spectrometry (SIMS) and fast atom bombardment mass spectrometry (FABMS) are of considerable importance as techniques for chemical characterization of surfaces. A mass spectrum of the surface layer provides not only compositional analysis from the elemental ions, but also chemical structure analysis from the cluster ions. Thus the chemical state of the surface is accessible in much the same way as the chemistry of an organic compound can be studied by organic mass spectrometry.
Recent advances in ion gun technology, utilizing liquid metal sources with beam diameters of < 1 pm provide the possibility of mapping the surface chemistry with a high degree of spatial resolution. This paper describes the application of SIMS imaging to ,a number of applied surface problems using a liquid gallium source. The experimental parameters and problems are described and discussed. In particular, since a large proportion of materials of practical interest are insulators, the procedures developed to permit the acquisition of spectra from such solids are outlined. Three main areas of application have been explored and are described: first, catalyst characterization where the chemical state and dispersion of active material has been monitored at the catalyst support surface; second, the characterization of optical coatings on glass; and third, studies of the chemistry of interfaces and dopants of InP device materials.
RBS and SIMS measurements of the fluence dependence of the range distributions of Pb implanted into Si( 111) crystals S Kostic, J J Jimenez-Rodriguez* and D G Armour, Department of Electronic and Electrical Engineering, Uniaersit) of Salford, Saljbrd M5 4 WT, UK
Rutherford backscattering measurements of the range distributions of Pb implanted into Si have consistently indicated a build up of Pb close to the surface at high fluences. This effect, which is associated with either segregation or range shortening (or a combination of both processes), has been investigated in detail using RBS and SIMS measurements of the depth profiles of Pb implanted into Si with fluences in the range 5 x 1O14m7.5xlOI cm-‘. The results obtained using the two analytical techniques are compared with theoretical prediction and the reasons for the fluence dependence of the range profiles are discussed.
* Department of Electricity and Electronics, Faculty of Physical Science, University of Madrid, Madrid 3, Spain.
Two-dimensional interfaces
electron gas systems at semiconductor
A C Cossard, A T & T Bell Laboratories, Murray Hill, Nebc Jersey 07974, USA
The heterointerface between epitaxial layers of dissimilar semiconductors forms a useful locusfor confinement of electrons to two-dimensional motion. Electrons with high mobilities and long scattering times may be introduced by modulation doping and display strong magneto quantum effects including the quantum 1021