engleski

Studying of trap levels by the use of focused ion beams

Ion beam induced charge (IBIC) is already well established technique used for studying electronic properties of semiconductor materials and devices. Recently introduced Time Resolved IBIC (TRIBIC) method gives additional possibility to observe and analyse electric response of semiconductors (on a time scale) to the impact of a single high energy ion. In this work we present an attempt to extend the use of focused ion beams in characterising semiconductor materials and so enrich the information available from IBIC and TRIBIC experiments. High energy protons focused by a nuclear microprobe equipped with a controlled temperature stage were used to irradiate fully depleted samples and fill the trap levels at low temperatures. Thermally stimulated current (TSC) was then recorded during heating as a function of temperature. We observed difference in TSC spectra collected between 100 K and 300 K by selective irradiation of the samples close to either positive or negative electrode. The preliminary results indicate the usefulness of the method and justify the use of the focused ion beams to distinguish between the hole and electron traps present in materials.

semiconductor materials and devices; IBIC; TRIBIC; thermally stimulated current

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