Spatial, LET and range dependence of enhanced charge collection by single ion strike in 4H-SiC MESFETs

The spatial dependence of transient currents induced in recessed 4H-SiC MESFETs by various ions with the same Linear Energy Transfer (LET) but different projected ranges is evaluated. The most largest signal is observed when ion strikes the Gate-to-Drain Recess (GDR). In addition, the signals are detected when an ion strikes the Gate-to-Source Recess (GSR), gate and drain. The charge enhancement mechanism is clarified by using numerical simulation. Finally we discuss the effect of ion energy, LET and projected range on the charge enhancement effect. It is found that the early stage of charge collection is insensitive to projected range, energy and diameter of ion track, however, depends on LET. The duration of charge collection is independent of projected range and LET, however, depends on energy.