An ion microscope equipped with a resistive anode encoder imaging system has been used to acquire molecular secondary ion images, with lateral resolution on the order of 1 microns, from several quaternary ammonium salts, an amino acid, and a polynuclear aromatic hydrocarbon which were deposited onto copper transmission electron microscope grids. All images were generated by using the secondary ion signal of the parent molecular species. The variation of parent and fragment molecular ion signals with primary ion dose indicates that, for many bulk organic compounds, bombardment-induced fragmentation of parent molecules saturates at primary ion doses of (1-8) X 10(14) ions/cm2. Subsequent ion impacts cause little further accumulation of damage in the sample, and intact parent molecular ions are sputtered even after prolonged ion bombardment (i.e. primary ion doses greater than 1 X 10(16) ions/cm2). This saturation process allows molecular images to be obtained at high primary ion doses and allows depth profiles to be obtained from simple molecular solid/metal test structures.
Low (keV) and high (MeV) energy Al and B implants were performed into n-type 6H- and 3C-SiC at both room temperature and 850 °C. The material was annealed at 1100, 1200, or 1400 °C for 10 min and characterized by secondary ion mass spectrometry, Rutherford backscattering (RBS), photoluminescence, Hall and capacitance-voltage measurement techniques. For both Al and B implants, the implant species was gettered at 0.7 Rp (where Rp is the projected range) in samples implanted at 850 °C and annealed at 1400 °C. In the samples that were amorphized by the room temperature implantation, a distinct damage peak remained in the RBS spectrum even after 1400 °C annealing. For the samples implanted at 850 °C, which were not amorphized, the damage peak disappeared after 1400 °C annealing. P-type conduction is observed only in samples implanted by Al at 850 °C and annealed at 1400 °C in Ar, with 1% dopant electrical activation.
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