Atomic-scale finishing of carbon face of single crystal SiC by combination of thermal oxidation pretreatment and slurry polishing

We present a miniaturized vertical-type two- dimensional hole gas (2DHG) diamond metal-oxide-semiconductor field-effect transistor (MOSFET) by adopting a gate-source overlapping structure. We developed a 2- $\mu \text{m}$ -wide trench and disposed a part of the gate electrode to overlap the Al2O3 insulator film on the source electrode to eliminate the space between source and gate electrode. We obtained the maximum drain current density of ${I}_{\text {D}} =12800$ A/cm2 at ${V}_{\text {DS}} = -50$ V and the specific on-resistance of ${R}_{\text {ON}}=3.2\,\,\text{m}\Omega $ cm2 at ${V}_{\text {DS}} = -10$ V and confirmed their improvement by the miniaturization of devices and reduction of source to gate resistance. In addition, the drain current on/off ratio was 7 orders magnitude even at 200 °C with the formation of a highly concentrated, thick nitrogen-doped layer as the current blocking layer.

Over 12000 A/cm 2 and 3.2 m $\Omega$ cm 2 Miniaturized Vertical-Type Two-Dimensional Hole Gas Diamond MOSFET

Growth of high-quality 4H-SiC epitaxial layers on 4° off-axis C-face 4H-SiC substrates

https://iopscience.iop.org/article/10.7567/JJAP.56.085504/pdf

Fabrication of large-sized TaC-coated carbon crucibles for the low-cost sublimation growth of large-diameter bulk SiC crystals

(111) vertical-type two-dimensional hole gas diamond MOSFETs with hexagonal trench structures

We report the successful demonstration of large current and high-speed switching properties of SiC V-groove trench gate MOSFETs (VMOSFETs). A drain current of 150 A (at V DS = 2 V and V GS = 18 V) and breakdown voltage of 960 V were achieved from a packaged 6 × 6 mm2 single chip. Moreover, short switching times of t r = 81 ns and t f = 32 ns were also obtained. To fabricate such VMOSFETs with high yield, highly uniform in-house epitaxial growth technology on a 150-mm-diameter wafer is also one of the keys, owing to its characteristic dependence on drift layer carrier concentration.

http://iopscience.iop.org/article/10.7567/JJAP.55.04ER05/pdf

Hironori Itoh

Papers

150 A SiC V-groove trench gate MOSFET with 6 × 6 mm2 chip size on a 150 mm C-face in-house epitaxial wafer

150 A SiC V-groove trench gate MOSFET with 6 × 6 mm