Leakage current conduction and reliability assessment of passivating thin silicon dioxide films on n-4H-SiC

Piyas Samanta; Krishna C. Mandal

doi:10.1117/12.2238875

9 September 2016 Leakage current conduction and reliability assessment of passivating thin silicon dioxide films on n-4H-SiC

Piyas Samanta, Krishna C. Mandal

Author Affiliations +

Proceedings Volume 9968, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVIII; 99680E (2016) https://doi.org/10.1117/12.2238875
Event: SPIE Optical Engineering + Applications, 2016, San Diego, California, United States

Abstract

We have analyzed the mechanisms of leakage current conduction in passivating silicon dioxide (SiO₂) films grown on (0 0 0 1) silicon (Si) face of n-type 4H-SiC (silicon carbide). It was observed that the experimentally measured gate current density in metal-oxide-silicon carbide (MOSiC) structures under positive gate bias at an oxide field Eox above 5 MV/cm is comprised of Fowler-Nordheim (FN) tunneling of electrons from the accumulated n-4H-SiC and Poole-Frenkel (PF) emission of trapped electrons from the localized neutral traps in the SiO₂ gap, IFN and IPF, respectively at temperatures between 27 and 200 °C. In MOSiC structures, PF mechanism dominates FN tunneling of electrons from the accumulation layer of n-4H-SiC due to high density (up to 10¹³ cm^-2) of carbon-related acceptor-like traps located at about 2.5 eV below the SiO₂ conduction band (CB). These current conduction mechanisms were taken into account in studying hole injection/trapping into 10 nm-thick tunnel oxide on the Si face of 4H-SiC during electron injection from n-4H-SiC under high-field electrical stress with positive bias on the heavily doped n-type polysilicon (n+-polySi) gate at a wide range of temperatures between 27 and 200 °C. Holes were generated in the n⁺-polySi anode material by the hot-electrons during their transport through thin oxide films at oxide electric fields E_ox from 5.6 to 8.0 MV/cm (prior to the intrinsic oxide breakdown field). Time-to-breakdown t_BD of the gate dielectric was found to follow reciprocal field (1/E) model irrespective of stress temperatures. Despite the significant amount of process-induced interfacial electron traps contributing to a large amount of leakage current via PF emission in thermally grown SiO₂ on the Si-face of n-4H-SiC, MOSiC devices having a 10 nm-thick SiO₂ film can be safely used in 5 V TTL logic circuits over a period of 10 years.

Conference Presentation

Citation Download Citation

Piyas Samanta and Krishna C. Mandal "Leakage current conduction and reliability assessment of passivating thin silicon dioxide films on n-4H-SiC", Proc. SPIE 9968, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVIII, 99680E (9 September 2016); https://doi.org/10.1117/12.2238875

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE