Company Name: Xiamen Powerway Advanced Material Co., Ltd
Tel: +86-592-5601404
Fax: +86-592-5745822
E-Mail: sic@powerwaywafer.com

Address: #3007-3008, No.89, Anling,Huli Developing Zone, Xiamen,China
Home > News > Hole injection and dielectric breakdown in 6H SiC and 4H SiC metal oxide semiconductor structures during substrate electron injection via Fowler Nordheim tunneling
Hole injection and dielectric breakdown in 6H SiC and 4H SiC metal oxide semiconductor structures during substrate electron injection via Fowler Nordheim tunneling


Highlights

•We model anode hole injection in 4H- & 6H–SiC MOS by substrate FN electron injection.

•We study oxide bandgap ionization under FN electron injection from n-4H- & n-6H–SiC.

•FN electron injections are considered at both constant Eox and current density jFN.

•4H–SiC devices show shorter time-to-oxide breakdown than 6H–SiC MOS at a givenEox.


Hole injection into silicon dioxide (SiO2) films (8–40 nm thick) is investigated for the first time during substrate electron injection via Fowler–Nordheim (FN) tunneling in n-type 4H- and 6H–SiC (silicon carbide) based metal–oxide–semiconductor (MOS) structures at a wide range of temperatures (T) between 298 and 598 K and oxide electric fields Eox from 6 to 10 MV/cm. Holes are generated in heavily doped n  -type polycrystalline silicon (n+-polySi) gate serving as the anode as well as in the bulk silicon dioxide (SiO2) film via hot-electron initiated band-to-band ionization (BTBI). In absence of oxide trapped charges, it is shown that at a given temperature, the hole injection rates from either of the above two mechanisms are higher in n-4H–SiC MOS devices than those in n-6H–SiC MOS structures when compared at a given Eox and SiO2 thickness (tox). On the other hand, relative to n-4H–SiC devices, n-6H–SiC structures exhibit higher hole injection rates for a given tox during substrate electron injection at a given FN current density je,FN throughout the temperature range studied here. These two observations clearly reveal that the substrate material (n-6H–SiC and n  -4H–SiC) dependencies on time-to-breakdown (tBD) or injected charge (electron) to breakdown (QBD) of the SiO2 film depend on the mode of FN injections (constant field/voltage and current) from the substrate which is further verified from the rigorous device simulation as well.

Keywords

  • Anode hole injection
  • Silicon dioxide
  • Wide bandgap semiconductor
  • 4H–SiC
  • 6H–SiC;
  • FN tunneling

Source:Sciencedirect

 

If you need more information about sic 6h, please visit:www.siliconcarbidewafer.com or send us email at sic@powerwaywafer.com