【作者】 王志俊；

【导师】 胡礼中；

【作者基本信息】 大连理工大学 ， 微电子学与固体电子学， 2006， 硕士

【摘要】 氧化镁（MgO）薄膜具有很多优良的物理化学性质,是一种非常好的缓冲层和介电保护层,在微电子器件领域存在巨大的应用潜力,因此受到众多研究者的关注。本文在Si衬底上采用PLD法在各种生长参数下生长了MgO薄膜,旨在优化薄膜的生长条件,获得高质量的MgO薄膜。利用X射线衍射（XRD）、扫描电子显微术（SEM）、原子力显微术（AFM）、反射式高能电子衍射（RHEED）等手段测试,对样品结构和表面形貌进行表征。实验发现在Si（111）衬底上很难得到理想质量的MgO薄膜,这可能是由于（111）取向的Si衬底与立方结构的MgO材料具有较大的晶格失配的原因。改用（100）取向的Si衬底,获得了很好的效果。XRD测试表明,衬底温度为400℃,氧压在10^-2pa以上时,沉积的MgO薄膜完全为（110）取向,并且薄膜的结晶质量随着氧压的增大而提高。氧压在10Pa时,衍射峰的半高宽约为0.0981°,薄膜的结晶质量最好,作者用羽辉等离子体内物质的相互作用对这一现象进行了解释。在没有氧压的时候,MgO薄膜主要是（100）取向。从SEM照片上可以看出在薄膜的表面有很多微粒存在,从AFM图片上看到晶粒为柱状结构,这可能是由于激光烧蚀出的原子到达衬底表面后迁移率较低的缘故,薄膜表面均方根粗糙度约为2.231nm。在长有MgO缓冲层的衬底上,氧压为10Pa,衬底温度为600℃时薄膜结晶质量最好,半高宽比没有缓冲层时减少0.0112°。从SEM和AFM照片看,在缓冲层上生长的MgO薄膜比没有缓冲层的MgO薄膜的表面更加光滑平整,均方根粗糙度减小1.532nm。AFM图片显示晶粒为粒状结构,可见,到达衬底表面的原子迁移率显著提高。更多还原

【Abstract】 Magnesium oxide (MgO) has attracted much attention, because it can be used as a buffer layer and a protective layer of dielectrics due to its superb properties, and has great potential in the microelectronic device application. In this paper, MgO thin films have been deposited on Si substrates under various conditions using pulsed laser deposition (PLD) with the purpose of optimizing the growth conditions to get high-quality MgO thin films. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and reflection high energy diffraction (RHEED) were used to characterize the structures and the morphologies of the samples. Ideal quality MgO thin films can’t be achieved on Si(111), that may be because there is big crystal lattice mismatch between Si(111) and MgO. However, a good result was received when Si(111) was replaced by Si(100). The XRD measurements show that when the substrate temperature was 400℃ and the oxygen pressure is more than 10~-2 Pa, the deposited MgO thin films had the completed (110) orientation and the crystalline quality improved as the oxygen pressure increased. When the oxygen pressure reached 10 Pa, the crystalline quality of the film appeared to be the best with a minimum full width at half maximum (FWHM) value of 0.0981°. This phenomenon is interpreted using the interaction between the species in the plume-like plasma. The MgO thin films deposited under no oxygen condition were oriented of (100). The surface of the MgO thin film is very smooth and flat with a root mean square (Rms) of 2.231 nm seen from SEM and AFM images. The structure of the grain is columnar, maybe because the ablated Mg had a low migrated ability. The MgO thin films deposited on MgO/Si(100) at 10 Pa had the best crystal quality when the substrate temperature reached to 600℃, and the value of FWHM was 0.0869° smaller than that of without a buffer layer. The surface became smoother and flatter with a smaller Rms reduced by about 1.532 nm, and the grain seemed to be granule, which shows that the migrated ability of ablated Mg has improved.更多还原