In this paper, an Al/Ti Schottky-electrode was fabricated on a 4H- SiC surface via sputtering, and an Al₂O₃ layer was inserted into the metal semiconductor contact-surface using atomic-layer deposition. We studied the inhomogeneity of the Schottky-barrier height by inserting the dielectric layer (Al₂O₃) with different thicknesses. The Schottky-barrier heights and ideality factors were extracted for different measurement temperatures. The experimental results show that the barrier height changes to only 9% and the ideality factor approaches 1. Moreover, with the insertion of Al₂O₃, the difference between$\varnothing$_eff and ${\varnothing }_B^0$ is most closer. This indicates the Al₂O₃ layer can passivate the surface defects to improve the contacts inhomogeneity. The TEM images also indicate that the insertion of Al₂O₃ reduces the diffusion of Ti into SiC to start a solid state reaction to form titanium silicides and carbides co-exist at the interface, which improves the inhomogeneity of the Schottky interface. In particular, the thickness of Al₂O₃ is 0.8 nm.

在本文中，通过溅射在4H-SiC表面上制备了Al / Ti肖特基电极，并通过原子层沉积将Al ₂ O ₃层插入金属半导体接触表面。我们通过插入不同厚度的介电层（Al ₂ O ₃）研究了肖特基势垒高度的不均匀性。针对不同的测量温度提取了肖特基势垒高度和理想因子。实验结果表明，该势垒高度变化到只有9％和理想因子接近1。此外，随着Al的插入₂ Ó ₃，之间的差$\varnothing$_eff和${\varnothing }_{乙}^0$最接近。这表明Al ₂ O ₃层可以钝化表面缺陷以改善接触不均匀性。TEM图像还表明，Al ₂ O ₃的插入减少了Ti向SiC中的扩散，从而开始固态反应，从而在界面处共存形成硅化钛和碳化物，从而改善了肖特基界面的不均匀性。特别地，Al ₂ O ₃的厚度为0.8nm。