Silicon carbide (SiC) is a promising microelectronic semiconductor with an infrared response that depends on factors such as polytype, growth conditions, and structuring. Recent advances in infrared nano-imaging techniques provide new opportunities to characterize thin films at the nanoscale. We performed tip-enhanced near-field spectral characterization on various 4H-SiC sample surfaces using photoinduced force microscopy (PiFM). The near-field spectra feature a peak associated with a surface phonon polariton (SPhP) resonance, which proves to be highly sensitive to the material’s surface quality. Interestingly, we found that the power absorption at the tip-sample junction, enhanced by the effective tip polarizability, can account for these PiFM spectra, resulting in a blend of both dispersive and dissipative spectral line shapes. As a potential application, a junction-field effect transistor was imaged to evaluate the technique’s ability to map the surface of different p- and n-doped areas, demonstrating high sensitivity and spatial resolution compared to Raman analysis.

中文翻译：

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碳化硅的红外光生力近场光谱


碳化硅 （SiC） 是一种很有前途的微电子半导体，其红外响应取决于多型、生长条件和结构等因素。红外纳米成像技术的最新进展为在纳米尺度上表征薄膜提供了新的机会。我们使用光诱导力显微镜 （PiFM） 对各种 4H-SiC 样品表面进行了针尖增强的近场光谱表征。近场光谱具有与表面声子极化激元 （SPhP） 共振相关的峰，事实证明，该共振对材料的表面质量高度敏感。有趣的是，我们发现针尖-样品结处的功率吸收，通过有效的针尖极化率增强，可以解释这些 PiFM 光谱，从而产生色散和耗散光谱线形状的混合。作为一项潜在的应用，对结场效应晶体管进行了成像，以评估该技术绘制不同 p 和 n 掺杂区域表面的能力，与拉曼分析相比，该技术表现出高灵敏度和空间分辨率。