Development of diagnostic method for deep levels in semiconductors using charge induced by heavy ion microbeams

• Charge Transient Spectroscopy using heavy ion microbeams (HIQTS) was developed.
• HIQTS system is connected with 3 MeV Tandem accelerator at JAEA Takasaki.
• Defects in 4H Silicon Carbide (SiC) Schottky diodes were evaluated using HIQTS.
• 6H-SiC pn diodes with partial damaged areas were also evaluated using HIQTS.

In order to study defects that create deep energy levels in semiconductors which act as carrier traps, Charge Transient Spectroscopy using heavy ion microbeams (HIQTS) was developed at JAEA Takasaki. The HIQTS system was connected with the heavy ion microbeam line of the 3 MV Tandem accelerator. Using the HIQTS system, deep levels in 4H-SiC Schottky barrier diodes irradiated with 3 MeV-protons were studied. As a result, a HIQTS peak with an activation energy of 0.73 eV was observed. In addition, local damage in 6H-SiC pn diodes partially irradiated with 12 MeV-O ion microbeams was studied using HIQTS. With increasing 12 MeV-O ion fluence, charge collection efficiency in locally damaged areas decreased and HIQTS signals increased.