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由Al,N掺杂的n型层和Al掺杂的P型层组成的高效SiC兰色发光二极管是在单晶6H-SiC衬底上用液相外延生长的。至今,通过Lely法或Acheson工艺生长的晶片已被用作衬底材料。但其不规则形状和约1cm~2的有限面积是SiC兰色发光二极管大规模生产的主要障碍。本文叙述了根据Lely工艺得到的较大SiC单晶锭的一种新方法。由于适当调整温度分布,所以结晶主要发生在反应室里与籽晶顶端相接的有限面积上。晶体生长在2200℃出现。用掺Al粉末和非掺杂SiC粉末的混
High-efficiency SiC blue LEDs consisting of Al, N-doped n-type and Al-doped p-type layers are grown by liquid-phase epitaxy on a single crystal 6H-SiC substrate. To date, wafers grown by the Lely method or Acheson process have been used as substrate materials. However, its irregular shape and the limited area of about 1 cm 2 are the main obstacles to the mass production of SiC blue LEDs. This article describes a new method for obtaining larger SiC single crystal ingots based on the Lely process. Due to the proper temperature profile, the crystallization occurs mainly in the limited area of the reaction chamber that is in contact with the top of the seed. Crystal growth appeared at 2200 ℃. Mix with Al powder and undoped SiC powder