Influence of Lateral Spreading of Implanted Aluminum Ions and Implantation-Induced Defects on Forward Current–Voltage Characteristics of 4H-SiC Junction Barrier Schottky Diodes

Forward current density (J
_F
)-forward voltage (V
_F
) characteristics are experimentally and computationally investigated for 4H-silicon carbide junction barrier Schottky (JBS) diodes with a lightly doped (3 - 5 times10
¹⁵
cm
^-3
) drift layer and 2-mum-wide p
⁺
stripe regions separated by 1 mum. The J
_F
-V
_F
characteristics of fabricated JBS diodes are compared with those of Schottky barrier diodes simultaneously fabricated on the same epitaxial wafers. These J
_F
-V
_F
characteristics are also compared with those of simulated JBS diodes, assuming boxlike and Monte Carlo-simulated profiles of aluminum. In the simulation of aluminum ion implantation, concentration contours of created interstitials and vacancies are calculated, and their influence on the J
_F
-V
_F
characteristics of JBS diodes is discussed in terms of degradation of electron mobility in the surface region of the drift layer.