Island-growth of SiCGe films on SiC

• 来源期刊: 中国物理B（英文版）
• 关键词: SiC SiCGe island-growth hot-wall low-pressure chemical vapour deposition
• 年，卷（期）: 2007,（11）
• 页码范围: 3470-3474
• 页数: 5页
• 语种: 英文

摘要

SiCGe ternary alloys have been grown on SiC by hot-wall low-pressure chemical vapour deposition. It has been found that the samples exhibit an island configuration, and the island growth of SiCGe epilayer depends on the processing parameters such as the growth temperature. When the growth temperature is comparatively low, the epilaycr has two types of islands: one is spherical island; another is cascading triangular island. With the increase of the growth temperature, the islands change from spherical to cascading triangular mode. The size and density of the islands depend on the growth duration and GeH4 flow-rate. A longer growth time and a larger GeH4 flow-rate can increase the size and density of the island in the initial stage of the epitaxy. In our case, The optimal growth for a high density of uniform islands occurred at a growth temperature of 1100℃ for 1-minute growth, with 10 SCCM GeH4, resulting in a narrow size distribution (about 30 nm diameter) and high density (about 3.5 × 1010 dots/cm2). The growth follows StranskiKrastanov mode (2D to 3D mode), both of the islands and the 2D growth layer have face-centred cubic structure, and the critical thickness of the 2D growth layer is only 2.5 nm.