Abstract

In this paper the effects of 5 MeV proton irradiation on nitrided SiO2/4H-SiC metal–oxide–semiconductor (MOS) capacitors are studied in detail and the related mechanisms are revealed. The density of interface states (Dit) is increased with the irradiation doses, and the annealing response suggests that the worse of Dit is mainly caused by displacement effect of proton irradiation. However, the X-rays photoelectron spectroscopy (XPS) measurement shows that the quantity proportion of breaking of Si≡N induced by displacement is only 8%, which means that the numbers of near interface electron traps (NIETs) and near interface hole traps (NIHTs) are not significantly changed by the displacement effect. The measurements of bidirectional high frequency (HF) C-V characteristics and positive bias stress stability show that the number of un-trapped NIETs and oxide electron traps decreased with increasing irradiation doses because they are filled by electrons resulted from the ionization effect of proton irradiation, benefiting to the field effective mobility (μFE) and threshold voltage stability of metal–oxide–semiconductor field-effect transistors (MOSFETs). The obviously negative shift of flat-band voltage (VFB) resulted from the dominant NIHTs induced by nitrogen passivation capture more holes produced by ionization effect, which has been revealed by the experimental samples with different nitrogen content under same irradiation dose.

Highlights

  • Because of the excellent electrical and thermal properties, silicon carbide (SiC) is a promising wide-bandgap semiconductor material with application in the power, high temperature, and space electronic fields [1,2]

  • In this paper the effects of 5 MeV proton irradiation on nitrided SiO2/4H-SiC MOS capacitors are studied in detail and the related mechanisms are revealed

  • The density of interface states (Dit) is increased with the irradiation doses, p/cm, which could lead to the failure of power metal–oxide–semiconductor field-effect transistors (MOSFETs)

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Summary

Introduction

Because of the excellent electrical and thermal properties, silicon carbide (SiC) is a promising wide-bandgap semiconductor material with application in the power, high temperature, and space electronic fields [1,2]. More research interests are turned to the irradiation effect of the nitrided MOS capacitors and power MOSFETs. The previous. Of Information addition, to positive chargesofgenerated gate oxide during mechanisms thepositive effect ofcharges ionization irradiation onfurther near interface which can significantly influence the μFEon of of are required to be studied.traps. Protonirradiation irradiation one main particles defects is is one of of thethe main particles in in space environment, and will make both the ionization effect and displacement effect. MOS for space study theto effects proton irradiation nitrided MOS capacitor andcapacitor. Measurement and annealing response of the samples, the ionization effect and displacement effect of proton irradiation irradiation on on interface interface traps and near interface traps are clarified, and the mechanisms of the proton variation of of the the μ μFE. FB are stress stability of VFB are discussed, discussed, which are important for the power MOSFET

Experiments
MeV protons using
SRIM simulation of the Capacitors injected by by a 5MeV
Gate Oxide Integrity
To were failed failed in inthe theC-V
Free Carrier Concentration
Near Interface Traps
Figures and
Si core level
Flat-Band
12. Before
Interface Traps
17. It can seen that the
Conclusions
Full Text
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