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采用自行设计的水平冷壁低压化学气相沉积(LPCVD)方法在偏向〈1120〉晶向8°的n型4H SiC(0001)衬底上进行了同质外延生长.在5 3×103Pa的低压下,外延膜生长速率超过3μm/h.电容电压法测试表明在非有意掺杂外延膜中净施主浓度为8 4×1016 cm-3.Nomarski显微镜观察表明厚外延膜的表面光滑,生长缺陷密度很低.AFM测试显示表面均方根粗糙度为0 3nm,没有观察到宏观台阶结构.Raman谱线清晰锐利,表现出典型的4H SiC特征.在低温PL谱中,近带边区域出现很强的自由激子峰,表明样品是高质量的.
Homogeneous epitaxial growth was carried out on an n-type 4H SiC (0001) substrate with an orientation of <1120> to 8 ° using a self-designed horizontal cold wall low pressure chemical vapor deposition (LPCVD) method at a low pressure of 5 3 × 10 3 Pa , Epitaxial film growth rate of more than 3μm / h. Capacitance voltage test showed that the net donor concentration in the non-intentionally doped epitaxial film was 8 4 × 1016 cm-3 .Nomarski microscopy showed that the thick epitaxial film surface smooth growth defect density is very Low.AFM test showed that the root mean square roughness of the surface was 0 3nm, no macroscopic step structure was observed.Raman spectrum was clear and sharp, showing the typical 4H SiC characteristics.In the low-temperature PL spectrum, the near-edge region appeared strong Free exciton peak, indicating that the sample is of high quality.