Investigation of the Boron removal effect induced by 5.5 MeV electrons on highly doped EPI- and Cz-silicon

Abstract

This study focuses on the properties of the BiOi (interstitial Boron - interstitial Oxygen) and CiOi (interstitial Carbon - interstitial Oxygen) defect complexes by 5.5 MeV electrons in low resistivity silicon. Two different types of diodes manufactured on p-type epitaxial and Czochralski silicon with a resistivity of about 10 Ω·cm were irradiated with fluence values between 1 × 1015 cm−2 and 6 × 1015 cm−2 . Such diodes cannot be fully depleted and thus the accurate evaluation of defect concentrations and properties (activation energy, capture cross-section, concentration) from Thermally Stimulated Currents (TSC) experiments alone is not possible. In this study we demonstrate that by performing Thermally Stimulated Capacitance (TS-Cap) experiments in similar conditions to TSC measurements and developing theoretical models for simulating both types of BiOi signals generated in TSC and TS-Cap measurements, accurate evaluations can be performed. The changes of the position-dependent electric field, the effective space charge density Neff profile as well as the occupation of the BiOi defect during the electric field dependent electron emission, are simulated as a function of temperature. The macroscopic properties (leakage current and Neff) extracted from current-voltage and capacitance-voltage measurements at 20 °C are also presented and discussed.