Solid phase crystallization of amorphous Si1−xGex films deposited on SiO2 by molecular beam epitaxy
Solid phase crystallization of amorphous Si1−xGex films deposited on SiO2 by molecular beam epitaxy
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分子束外延沉积在 SiO2 上的非晶 Si1−xGex 薄膜的固相结晶
DOI：
10.1063/1.358654
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发表时间：
1995
影响因子：
3.2
通讯作者：
Changsoo Kim
中科院分区：
文献类型：
--
作者：
C. Hwang;M. Ryu;Ki;Seung;Changsoo Kim
用X射线衍射仪和透射电子显微镜研究了分子束外延生长的非晶态Si1−xGex(x=0~0.5 3)合金层的固相晶化行为。结果表明，随着薄膜中Ge浓度的增加，薄膜完全晶化所需的热平衡显著降低。此外，我们还发现纯非晶Si薄膜具有较强的(111)织构，而Si1−xGex合金薄膜具有较强的(311)织构，表明Ge的掺入改变了固相晶化机制。晶化膜的透射电子显微镜分析表明，纯硅的晶型为椭圆形和/或枝晶状，晶内有较高密度的微孪晶，而Si0.47Ge0.53合金的晶型大致为等轴状，缺陷密度较低。结果表明，晶化机制由孪晶辅助生长转变为非晶态晶化。
We have investigated solid phase crystallization behavior of the molecular beam epitaxy grown amorphous Si1−xGex (x=0 to 0.53) alloy layers using x‐ray diffractometry and transmission electron microscopy (TEM). Our results show that the thermal budget for the full crystallization of the film is significantly reduced as the Ge concentration in the film is increased. In addition, we find that a pure amorphous Si film crystallizes with a strong (111) texture while that of the Si1−xGex alloy film crystallizes with a (311) texture suggesting that the solid phase crystallization mechanism is changed by the incorporation of Ge. TEM analysis of the crystallized film shows that the grain morphology of the pure Si is an elliptical and/or a dendrite shape with a high density of microtwins in the grains while that of the Si0.47Ge0.53 alloy is more or less equiaxed shape with a much lower density of defects. From these results, we conclude that the crystallization mechanism changes from a twin‐assisted growth mode to ...