Improved Silicon Carbide on Silicon Crystal Quality by Epitaxial Necking

摘要CTS-9319770 James埃德加 为了降低硅衬底上碳化硅（SiC）薄膜的缺陷密度，发展了局域化的有限区域外延。 假设是消除通过颈缩过程的缺陷传播，其中缺陷终止于SiC的侧平面上;颈缩过程后沉积的外延碳化硅应包含较少的缺陷。 在二氧化硅掩模硅上的选择性碳化硅生长和在非平面图案化硅上的各向异性生长都被检查为将外延限制在小区域的方法。 探索了使用氯代烃和硅烷与氦气作为载气的新的源化学，试图在降低的温度下选择性外延生长，并增加在各种晶面上的生长各向异性。 窗口图案的形状和方向、源材料的氯含量、 改变操作压力和温度以使缺陷的传播最小化。 碳化硅是许多电子和光电应用的有吸引力的半导体，包括高速，高功率器件，必须在高温下工作的器件，微机电传感器和日盲紫外探测器。 然而，这种应用受到在其他半导体上获得低缺陷碳化硅膜的困难的阻碍。 本研究所要解决的正是这一问题。

ABSTRACT CTS-9319770 James Edgar Localized, confined-area epitaxy is developed to reduce the defect density of silicon-carbide (SiC) films on silicon (Si) substrates. The hypothesis is to eliminate defect propagation through the necking process, in which defects terminate on the side planes of the SiC; epitaxial silicon carbide deposited after the necking process should contain fewer defects. Both selective silicon carbide growth on silica-masked silicon and anisotropic growth on nonplanar patterned silicon are examined as methods of confining epitaxy to small areas. New source chemistries using chlorinated hydrocarbons and silanes with helium as a carrier gas are explored in attempts to selective epitaxial growth at reduced temperatures and to increase growth anisotropy on various crystal planes. The shape and orientation of the window pattern, the chlorine content of the source materials, the operating pressure, and temperature are varied to minimize the propagation of defects. Silicon carbide is an attractive semiconductor for many electronic and optoelectronic applications, including high-speed, high-power devices, devices that must operate at elevated temperatures, microelectromechanical sensors, and solar-blind ultraviolet detectors. However, such applications are hampered by the difficulty of obtaining low-defect silicon-carbide films on other semiconductors. It is this issue that is addressed in this research.