HRXRD研究SiN盖帽层在Si中引入的应变

Study on Strain of Si Induced by SiN Cap Using HRXRD

为了研究SiN盖帽层在Si中引入应变的机理与控制,利用高分辨X射线衍射(HRXRD)技术分析了Si中应变的各向异性以及与盖帽层厚度的关系。研究发现,盖帽层厚度低于300nm时,应变量与厚度呈近线性关系,随后增加趋缓,最终达到一饱和值;同时,应变在不同晶向表现出明显的各向异性,表层应变Si与未应变Si衬底在(004)晶面上的衍射峰重叠在一起,而(111)晶面的2个衍射峰可明显地被分离,且倾角对Si衬底衍射峰半高宽具有明显的展宽。

To analyze the mechanism of strain in Si induced by SiN and control strain, the relation of the strain in Si with thickness of SiN cap is studied using high-resolution X-ray diffraction （HRXRD）. The results show that the strain degree is a linear relationship with the cap layer thickness less than ＇300nm, and then increases slowly, reaches a saturation value at the 450nm thickness. Meanwhile, the strain shows obviously anisotropy at different directions. The diffraction peak of strained-Si does not separate from the peak of substrate on （004） crystal plane, but there is a clear separation of the two peaks on （111） plane, and tilt broadens the half width of diffraction peak.