scholarly journals Ion implantation in GaN at liquid-nitrogen temperature: Structural characteristics and amorphization

1998 ◽  
Vol 57 (4) ◽  
pp. 2530-2535 ◽  
Author(s):  
C. Liu ◽  
B. Mensching ◽  
M. Zeitler ◽  
K. Volz ◽  
B. Rauschenbach
Keyword(s):  
Ion Implantation ◽  
Liquid Nitrogen ◽  
Structural Characteristics ◽  
Liquid Nitrogen Temperature

Ion Damage and Annealing of Epitaxial Gallium Nitride and Comparison With GaAs/AlGaAs Materials

1995 ◽  
Vol 395 ◽  
Author(s):  
H.H. Tan ◽  
J.S. Williams ◽  
C. Yuan ◽  
S.J. Pearton
Keyword(s):  
Gallium Nitride ◽  
Ion Implantation ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Annealing Behaviour ◽  
Al Content ◽  
Ion Channeling ◽  
Ion Damage ◽  
High Al Content

ABSTRACTIon damage build up has been measured by ion channeling in good quality epitaxial GaN films on sapphire. GaN is found to be remarkably resistant to ion damage, with extremely efficient dynamic defect annihilation occurring at liquid nitrogen temperature during ion implantation. When disorder does accumulate at doses around 1016cm−2 of 90 keV Si ions, the surface appears to be a strong sink for damage build up and possibly the nucleation of amorphous layers. Once ion disorder has been produced in GaN, it is extremely difficult to remove by annealing. GaN exhibits disordering and annealing behaviour which is somewhat similar to that in high Al-content AlGaAs.

On The Formation of Si Oxide by Ion Implantation

1985 ◽  
Vol 45 ◽  
Author(s):  
F. Namavar ◽  
J.I. Budnick ◽  
F.H. Sanchez ◽  
H.C. Hayden
Keyword(s):  
Ion Implantation ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Experimental Situation ◽  
Liquid Nitrogen Temperature ◽  
Excess Oxygen ◽  
Implantation Temperature ◽  
Current Densities

ABSTRACTOxygen 0+ ions have been implanted into Si both at room temperature and liquid nitrogen temperature in order to determine the effect of implantation temperature on SiO2 formation. Samples were analysed by RBS with 1.5 MeV He+ ions. The implants of 0+ in Si were done at 150 keV with current densities of ≤10 μA/cm2. For doses of more than 1.5×1018 0+/cm2, in-situ RBS experiments positively indicate a 2:1 oxygen silicon ratio. Increased 0+ doses (for both room temperature and liquid nitrogen temperature) cause the Si02 layers to spread uniformly and symmetrically toward both the surface and the interior. From these results, it is apparent that excess oxygen diffuses toward Si/Si02 interfaces in our experimental situation even at liquid nitrogen temperature.

scholarly journals Ion Implantation and Annealing of Oxides

1986 ◽  
Vol 74 ◽  
Author(s):  
C. W. White ◽  
L. A. Boatner ◽  
P. S. Sklad ◽  
C. J. Mchargue ◽  
S. J. Pennycook ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Liquid Nitrogen ◽  
Amorphous Phase ◽  
Room Temperature ◽  
Solid Phase ◽  
Liquid Nitrogen Temperature ◽  
Pure Material ◽  
Near Surface ◽  
Implantation Damage ◽  
Crystalline Oxides

AbstractIon implantation damage and annealing results are presented for a number of crystalline oxides. In A12 O3, the amorphous phase produced by ion bombardment of the pure material first crystallizes in the (crystalline) γ phase. This is followed by the transformation of γ-Al2 O3 to α-A12O3 at a well defined interface. The activation energy for the growth of α alumina from γ is 3.6 eV/atom. In CaTiO3, the implantation-induced amorphous phase transforms to the crystalline phase by solid-phase epitaxy (SPE). ZnO is observed to remain crystalline even after high implantation doses at liquid nitrogen temperatures. The near surface of KTaO3 is transformed to a polycrystalline state after implantation at room temperature or liquid nitrogen temperature.

Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

1982 ◽  
Vol 40 ◽  
pp. 402-403 ◽  
Author(s):  
Claude Lechene
Keyword(s):  
Liquid Nitrogen ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Cultured Cells ◽  
Liquid Nitrogen Temperature ◽  
Elemental Content ◽  
Isolated Cells ◽  
Renal Tubular Cells ◽  
Diamond Saw ◽  
Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations

1973 ◽  
Vol 31 ◽  
pp. 114-115
Author(s):  
O. T. Inal ◽  
L. E. Murr
Keyword(s):  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Surface Atom ◽  
Image Brightness ◽  
Field Ion Microscopy ◽  
Topographic Features ◽  
Bcc Metals ◽  
Electron Orbital ◽  
Ion Microscopy ◽  
Field Ion Microscope

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Water accumulation as a function of temperature on specimens in an electron microscope cold stage

1986 ◽  
Vol 44 ◽  
pp. 114-115 ◽  
Author(s):  
M.K. Lamvik ◽  
D.A. Kopf ◽  
S.D. Davilla ◽  
J.D. Robertson
Keyword(s):  
Electron Microscope ◽  
Mass Loss ◽  
Liquid Helium ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Liquid Helium Temperature ◽  
Helium Temperature ◽  
Cold Stage ◽  
Water Accumulation ◽  
Better Than

Last year we reported1 that there is a striking reduction in the rate of mass loss when a specimen is observed at liquid helium temperature. It is important to determine whether liquid helium temperature is significantly better than liquid nitrogen temperature. This requires a good understanding of mass loss effects in cold stages around 100K.

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