Si衬底上SrMnO_3缓冲层对La_(0.8)Sr_(0.2)MnO_3薄膜择优取向生长的影响

Preferentially Oriented Effect of SrMnO_3 Buffer Layer to La_(0.8)Sr_(0.2)MnO_3 Thin Films on Si (100) Substrate

利用磁控溅射方法在 (1 0 0 )Si衬底上首先生长SrMnO3(SMO)作为缓冲层 ,再沉积得到了 (1 1 0 )择优取向生长的La0 .8Sr0 .2 MnO3(LSMO)薄膜。利用X射线衍射仪分析了SMO缓冲层的结构特征对LSMO薄膜择优取向生长的影响。结果表明 :当沉积温度为 60 0℃时 ,增加缓冲层SMO的厚度 ,LSMO薄膜的取向性变好 ;当缓冲层SMO厚度为 45nm时 ,LSMO薄膜基本具有 (1 1 0 )取向生长的特征。进一步的工作证实 :提高沉积温度 ,能够显著增加SMO缓冲层的晶粒大小 ,并减少LSMO薄膜择优取向生长所需的缓冲层厚度 ;当沉积温度为 80 0℃时 ,由于类退火作用的存在 ,厚度为 1 0nm的SMO缓冲层就可以实现LSMO薄膜择优取向的生长。

SrMnO_3 buffer layers were pre-deposited on Si (100) substrates by RF magnetron sputtering, then La_ 0.8Sr_ 0.2MnO_3(LSMO) thin film with a preferential (110) orientation was obtained on SrMnO_3(SMO) buffer layers. The effect of SMO buffer layers on the preferential orientation of LSMO was analyzed by X-ray diffraction (XRD). It is found that the orientation of LSMO films is improved with increasing the thickness of SrMnO_3 buffer layers grown at 600 ℃. When the thickness of SMO buffer layer is increased to 45 nm, a preferential (110) orientation of LSMO is shown. Moreover, the crystal size of SMO buffer layer can be remarkably increased and the thickness of SMO buffer layer that decided the LSMO orientation can be decreased, when the substrate temperature increased. Meanwhile, the preferential orientation of LSMO can be realized when the SMO buffer layer grown at 800 ℃ is only 10 nm, because of the existence of in-situ annealing.