Growth Characteristics of Calcium Silicides Films from the Deposited Ca Films at the Different Sputtering Ar Pressure
Thin Ca films were deposited directly on Si(100) substrates at the different deposition Ar pressure using Radio Frequency (R.F.) magnetron sputtering system (MS) and subsequent annealed at 800°C for 2.5h or 1.5h in a vacuum furnace, respectively. The double-structure Ca2Si films and Ca5Si3 film are grown directly and individually on Si(100) substrates by an interdiffusion process between the deposited Ca atoms and Si bulk crystals, respectively. Experimental results indicated that the selective grown of a single phase calcium silicide in multiple silicide phases in Ca-Si system depends on sputtering condition, annealing temperature and annealing time, especially sputtering condition is the principal factor for the selective grown because it is close contacted with the morphological character, the bombardment defect, the nucleation density of a calcium silicide in a calcium silicides system by bombardment intensity and so on. Besides, 800°C is the adaptive annealing temperature for a single calcium silicide film growth. Keywords-Ca2Si; Ca5Si3; Nucleation; Semiconducting silicides; MS; Annealing
Gold‐aluminum thin‐film interactions and compound formation
Phase formation has been studied in Au‐Al thin‐film interactions by means of 4He+ MeV backscattering and x‐ray diffraction techniques. The films were annealded at temperatures low enough for no liquid phase formation. Au4Al, Au5Al2, Au2Al, AuAl, and AuAl2 were detected from samples prepared by depositing the exact stoichiometry quantities of Au and Al. The phase formation sequence was determined. The first phase formed is Au5Al2; the others are observed with the disappearence of one phase previously formed. For instance, Au4Al grows only when all Al is reacted and, on the other hand, AuAl2 when all Au is reacted. The sequence of the phases in the Au‐Al interactions cannot be interpreted on the basis of pure thermodynamic or kinetic arguments and a composite mechanism is proposed.
Anomalous Annealing Behavior of Arsenic Implanted Silicon as a Function of Dose and Energy
Anomalous annealing behavior of damage in As implanted Si has been investigated by channeling effect measurements. Room temperature As implants with doses from 1014 to 2 × 1016cm-2 at energies ranging from 50 to 250 keV into Si were annealed over the range of 600°C to 1100°C. Anneal temperatures ≥ 950°C reduce the disorder for ion doses of 0.5 to 1 × 1016 cm-2 at energies between 50 and 250 keV. Anomalously high residual disorder was found for the intermediate doses of 2 × 1014 to 2 × 10/cm2 implanted above 100 keV. For this intermediate dose, annealing of implants performed at liquid nitrogen temperatures did not show significant reduction in this damage. However implants at 200° to 300°C indicate a lower amount of damage compared to the room temperature implants.