Articolo in rivista, 2020, ENG, 10.1063/5.0012029

Active dopant profiling and Ohmic contacts behavior in degenerate n-type implanted silicon carbide

Spera, Monia; Greco, Giuseppe; Severino, Andrea; Vivona, Marilena; Fiorenza, Patrick; Giannazzo, Filippo; Roccaforte, Fabrizio

CNR-IMM, Catania, Italy STMicroelectronics, Catania, Italy

This Letter reports on the active dopant profiling and Ohmic contact behavior in degenerate P-implanted silicon carbide (4H-SiC) layers. Hall measurements showed a nearly temperature-independent electron density, corresponding to an electrical activation of about 80% of the total implanted dose. Using the Hall result as calibration, the depth resolved active P-profile was extracted by scanning capacitance microscopy (SCM). Such information on the active P-profile permitted to elucidate the current injection mechanism at the interface of annealed Ni Ohmic contacts with the degenerate n-type 4H-SiC layer. Modeling the temperature dependence of the specific contact resistance with the thermionic field emission mechanism allowed extracting a doping concentration of 8.5x10(19)cm(-3) below the metal/4H-SiC interface, in excellent agreement with the value independently obtained by the SCM depth profiling. The demonstrated active dopant profiling methodology can have important implications in the 4H-SiC device technology.

Applied physics letters 117 (1), pp. 013502-1–013502-4

Keywords

silicon carbide, ion implantation, ohmi contacts

CNR authors

Spera Monia, Roccaforte Fabrizio, Giannazzo Filippo, Fiorenza Patrick, Greco Giuseppe, Vivona Marilena

CNR institutes

IMM – Istituto per la microelettronica e microsistemi