低束流Nd^(3+)注入硅基薄膜结构及光致发光的研究

Investigation on the Structure and Photoluminescence Properties of Nd Ion Implanted Silicon Film with Low Flux

采用金属蒸气真空弧离子源（MEVVA）制备了掺Nd3+硅基薄膜材料。用扫描电镜和X射线衍射观测了表面形貌及物相结构随注入条件、退火温度的变化,样品经1000°C退火处理形成NdSi相钕硅化合物。测试了样品的光致荧光谱,在254nm（～5.0eV）光激发下获得了紫蓝光区（410～430nm）和红光区（746nm）荧光发射,随着退火温度的升高,荧光强度增大。746nm红光光谱显示了Nd3+特征光发射跃迁（4F7/2,4S3/2→4I9/2）,讨论了注入层结构与荧光发射的相关性。

Semiconductor light-emitting materials are very important to visible displaying devices and to optoelectronics. In view of that silicon is a nonfungible semiconductor microelectronics material due to its excellent quality and low cost, therefore in the field of optoelectronics, people have long been looking forward to the realization of Si-based integrated optoelectronics by taking advantage of Si planar technique. The Si-based light emitting materials doped by rare-earth have received increasing attention in recent years. As for the rare-earth doped materials, neodymium (Nd3+) ion is a very versatile active ion which is widely used in laser crystal and fluoride glass due to the capabilities for the integrated optoelectronics.We reported the optical properties of Nd-incorporated into crystalline silicon by MEVVA (Metal Vapor Vacuum Arc) ion source implantation. In our work, the doses of the Nd ion were 8×1016, 1×1017, 3×l017cm-2, respectively. The low Nd ion flux (-4.5μA·cm-2) was employed in case of the increasing of the target temperature during the implantation. The samples were subsequently treated by rapid thermal annealing (RTA) at 700,800,900 and 1 000°C for 20s under ambient nitrogen gas. Comprehensive analysis including scanning electron microscope (SEM) and X-ray diffraction (XRD) indicated that the morphology and the structure of the samples were closely relative to the dose of implantation and the temperature of rapid thermal annealing, and NdSi was formed under the annealed temperature of 1 000°C. The blue light band (410-430nm) and red light band (746nm) photoluminescence were observed under the excitation of 254nm (-5.0eV), the intensity of those light emission gradually ascended with increasing the annealing temperature. The red emission (-746nm) is related to the intra-4f shell of Nd3+ radiation transition (4F7/2, 4S3/2→4I9/2). the correlation of the photoluminescence and the structure are also discussed.