Analysis of the inhomogeneous barrier and phase composition of W/4H-SiC Schottky contacts formed at different annealing temperatures

• 来源期刊: 中国物理B（英文版）
• 关键词: SiC Schottky contact inhomogeneity barrier x-ray diffraction (XRD)
• 年，卷（期）: 2018,（9）
• 页码范围: 596-601
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/9/097305

摘要

The electrical characteristics of W/4H-SiC Schottky contacts formed at different annealing temperatures have been measured by using current-voltage-temperatures(I-V-T)and capacitance-voltage-temperatures(C-V-T)techniques in the temperature range of 25℃-175℃.The testing temperature dependence of the barrier height(BH)and ideality factor(n)indicates the presence of inhomogeneous barrier.Tung''s model has been applied to evaluate the degree of inhomo-geneity,and it is found that the 400℃ annealed sample has the lowest T0 of 44.6 K among all the Schottky contacts.The barrier height obtained from C-V-T measurement is independent of the testing temperature,which suggests a uniform BH.The x-ray diffraction(XRD)analysis shows that there are two kinds of space groups of W when it is deposited or annealed at lower temperature(6500℃).The phase of W2C appears in the sample annealed at 600℃,which results in the low BH and the high T0.The 500℃ annealed sample has the highest BH at all testing temperatures,indicating an optimal annealing temperature for the W/4H-SiC Schottky rectifier for high-temperature application.