The objective of the present study was to investigate the effects of femtosecond laser-induced modifications on the current–voltage ( I – V ) characteristics between Ni electrodes deposited on laser-irradiated areas on n -type 4H–SiC crystals. We investigated the I – V characteristics and their changes from low-temperature annealing at 400 °C or 500 °C. The I – V characteristics were not the typical Schottky ones, but nonlinear and without a rectifying voltage range even before annealing, and they approached linear with longer annealing durations. An almost linear (i.e., ohmic) I – V curve was obtained for the sample annealed at 500 °C for 18 min. A selected area diffraction pattern taken from the cross section of a laser-irradiated line in the annealed sample was composed of diffraction spots from pure Ni and δ-Ni 2 Si grains. The coarse-grained Ni 2 Si phase had an orientation relationship with the SiC crystal, i.e., SiC(0001)//Ni 2 Si(100) and SiC $$(1\stackrel{-}{1}00)$$ ( 1 1 - 00 ) //Ni 2 Si(013).

中文翻译：

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在飞秒激光修饰的 4H-SiC 表面形成欧姆 Ni 电极

本研究的目的是研究飞秒激光诱导修改对沉积在 n 型 4H-SiC 晶体激光照射区域上的 Ni 电极之间的电流 - 电压（ I - V ）特性的影响。我们研究了 I-V 特性及其在 400 °C 或 500 °C 低温退火后的变化。I-V 特性不是典型的肖特基特性，而是非线性的，甚至在退火之前也没有整流电压范围，并且随着更长的退火持续时间，它们接近线性。对于在 500 °C 下退火 18 分钟的样品，获得了几乎线性（即欧姆）的 I-V 曲线。取自退火样品中激光照射线的横截面的选区衍射图案由纯Ni和δ-Ni 2 Si晶粒的衍射斑点组成。