Response of Ni/4H-SiC Schottky barrier diodes to alpha-particle irradiation at different fluences

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• 作者：E. Omotoso^a ; ^b ; ^{ezekiel.omotoso@up.ac.za" class="auth_mail" title="E-mail the corresponding author} ; W.E. Meyer^a ; F.D. Auret^a ; M. Diale^a ; P.N.M. Ngoepe^a
• 关键词：DLTS ; Free carrier removal rate ; Carrier concentration ; 4H-SiC ; Alpha-particle irradiation
• 刊名：Physica B: Physics of Condensed Matter
• 出版年：2016
• 出版时间：1 January 2016
• 年：2016
• 卷：480
• 期：Complete
• 页码：196-200
• 全文大小：956 K

文摘

Irradiation experiments have been carried out on 1.9×10¹⁶ cm⁻³ nitrogen-doped 4H-SiC at room temperature using 5.4 MeV alpha-particle irradiation over a fluence ranges from 2.6×10¹⁰ to 9.2×10¹¹ cm⁻². Current–voltage (I–V), capacitance–voltage (C–V) and deep level transient spectroscopy (DLTS) measurements have been carried out to study the change in characteristics of the devices and free carrier removal rate due to alpha-particle irradiation, respectively. As radiation fluence increases, the ideality factors increased from 1.20 to 1.85 but the Schottky barrier height (SBH_I–V) decreased from 1.47 to 1.34 eV. Free carrier concentration, N_d decreased with increasing fluence from 1.7×10¹⁶ to 1.1×10¹⁶ cm⁻² at approximately 0.70 μm depth. The reduction in N_d shows that defects were induced during the irradiation and have effect on compensating the free carrier. The free carrier removal rate was estimated to be 6480±70 cm⁻¹. Alpha-particle irradiation introduced two electron traps (E_0.39 and E_0.62), with activation energies of 0.39±0.03 eV and 0.62±0.08 eV, respectively. The E_0.39 as attribute related to silicon or carbon vacancy, while the E_0.62 has the attribute of Z₁/Z₂.