High-quality schottky and ohmic contacts in planar 4H-SiC metal semiconductor field-effect transistors and device performance

Abstract

We have fabricated planar 4H-SiC, metal-semiconductor field-effect transistors (MESFETs) with high-quality metal/SiC contacts. To eliminate potential damage to the gate region caused by etching and simplify the device fabrication process, gate Schottky contacts were formed without any recess gate etching, and an ideality factor of 1.03 was obtained for these gate contacts. The interface state density between the contact metal and SiC was 5.7 ϫ 10 12 cm Ϫ2 eV Ϫ1 , which was found from the relationship between the barrier height and the metal work function. These results indicate that the interface was well controlled. Thus, a transconductance of 30 mS/mm was achieved with a 3-µm gate length as the performance figure of these MESFETs with high-quality metal/SiC contacts. Also, a low ohmic contact resistance of 1.2 ϫ 10 Ϫ6 Ωcm 2 was obtained for the source and drain ohmic contacts by using ion implantation.

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“…18͒ and the 4H-SiC electron affinity ͑ 4H-SiC Ϸ 3.7 eV͒. 19 We find 0.85 eV, instead of 0.8 eV, predicted by the simple model, and this supports completely our assumptions. The mSBH in the case of EG can now be explained in terms of a pinning of E F,EG at an average value ⌬ ϳ 0.49 eV higher than E F,DG , as shown in Fig.…”

Graphene Schottky diodes: An experimental review of the rectifying graphene/semiconductor heterojunction

“…10(a) and (b)). Assuming a workfunction of 4.5 eV for graphene and considering the electron affinity of 3.7 eV for 4H-SiC [125]), eq. ( 8) would imply a eV B 8 .…”

Nanocrystalline 3C-SiC Electrode for Biosensing Applications

“…It was conductive and the resistivity was about 3.5–6.2 kΩ cm. The samples were cleaned to remove any inorganic and organic contaminations …”