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Reconstruction of ion gun and its application for deposition of thin films and nanostructures
Novák, Tomáš ; Mach, Jindřich (referee) ; Voborný, Stanislav (advisor)
This bachelor´s thesis deals with modification and experimental application of the ion device, generating and transporting nitrogen ion beam with energy in a range of 10-100 eV. Together with gallium effusion cell, this device can be used for deposition of gallium nitride (GaN) thin films. Nitrogen ion beam current significantly increased by shortening the optical part of the ion gun. A differential pumping provides the system with ultrahigh-vacuum conditions in the deposition chamber. Profiles of ion current density, appropriate for GaN depositions, were found by the optimization of potentials applied on electrodes of the ion gun. Due to increase of nitrogen-ion current, the depositon rate of the system raised from about tenth of nm/h to more than 10 nm/h. For experiments described in this paper, monocrystalline silicon (111) was used as a substrate. The effect of gallium and nitrogen ion fluxes on GaN growth was investigated, together with the effect of gold nanoparticles on a GaN growth. Thin films were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Several specific morphologies of thin films were observed.
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Reconstruction of ion gun and its application for deposition of thin films and nanostructures
Novák, Tomáš ; Mach, Jindřich (referee) ; Voborný, Stanislav (advisor)
This bachelor´s thesis deals with modification and experimental application of the ion device, generating and transporting nitrogen ion beam with energy in a range of 10-100 eV. Together with gallium effusion cell, this device can be used for deposition of gallium nitride (GaN) thin films. Nitrogen ion beam current significantly increased by shortening the optical part of the ion gun. A differential pumping provides the system with ultrahigh-vacuum conditions in the deposition chamber. Profiles of ion current density, appropriate for GaN depositions, were found by the optimization of potentials applied on electrodes of the ion gun. Due to increase of nitrogen-ion current, the depositon rate of the system raised from about tenth of nm/h to more than 10 nm/h. For experiments described in this paper, monocrystalline silicon (111) was used as a substrate. The effect of gallium and nitrogen ion fluxes on GaN growth was investigated, together with the effect of gold nanoparticles on a GaN growth. Thin films were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Several specific morphologies of thin films were observed.
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