The donor concentration in silicon implanted silicon and silicon on sapphire

Summary form only given. The effective number of carriers in self-implanted silicon on sapphire is studied. The penetration of the materials by the double solid phase epitaxy method (DSPE) is discussed. In order to measure the depth distribution of the implantation-induced donors, silicon was implanted in 2 ohm cm n-type (100) Czochralski-grown silicon. The implantations were made at energies of 300 and 100 keV to form a 0.5-μm thick amorphous layer. The silicon implantations were annealed at 550, 600, 700, 800, 900 or 1000°C respectively. A p⁺n-diode was made by implanting 1×10¹⁵ boron ions/cm² at an energy of 30 keV. The depth distributions of the silicon implantation induced donors were measured by C-V profiling. The implantation-induced donors are formed by deep levels in the bandgap. The energy distribution of these levels in silicon-implanted silicon was measured with deep-level transient spectroscopy (DLTS) for samples annealed at temperatures between 550 and 1000°C. DLTS measurements on p⁺n and n⁺p-diodes in silicon on sapphire have also been performed. A low number of deep-level defects was found in the former while defects probably formed by vacancy-carbon-oxygen complexes and by silicon di-interstitials were seen in the n⁺p-diodes