金属电阻率Cu/Cu_2O半导体弥散复合薄膜的制备及其偏压效应

Fabrication of semiconducting Cu/Cu_2O dispersive composite thin films with metallic resistivity and the bias voltage effect

采用平衡直流磁控溅射技术,通过改变衬底偏压在玻璃衬底上制备了Cu/Cu2O 弥散复合薄膜,并利用扫描电子显微镜、X射线衍射仪、四探针测试仪和紫外-可见分光光度计等进行表征与分析.研究发现,Cu/Cu2O 弥散复合薄膜表现出金属和半导体双特性,其电阻率范围为（5.23-9.98）×10^-5 Ω·cm,禁带宽度范围为2.23-2.47eV.同时,研究还发现衬底偏压对Cu/Cu2O 弥散复合薄膜的形貌、结构、电学和光学性能都产生了较大的影响,特别是当衬底偏压为-100V时薄膜样品的表面最为致密,结晶程度最好,电阻率最低,禁带宽度最窄.进一步地,对平衡磁控溅射过程的偏压效应进行了分析,并提出了两种区别于传统轰击和再溅射作用的新机制.

Cu/Cu2 O dispersive composite thin films were successfully fabricated on glass slides using direct current-balanced magnetron sputtering technology by changing the substrate bias voltage.Scanning electron microscope,X-ray diffractometer,four-point probe instrument and ultraviolet-visible spectrophotometer were applied for a detailed characterization.It was found that as-prepared composite thin films show an intriguing combination of metal and semiconductor characteristics with resistivity of(5.23-9.98)× 10-5Ω·cm and bandgap of2.23-2.47 eV.It was also found that the substrate bias voltage influences the morphology,structure,electrical and optical properties greatly.Especially,when the substrate bias voltage was-100 V,as-prepared composite thin film presents a condensed morphology and a well-crystallized structure with the lowest resistivity and the narrowest bandgap.Further,the bias voltage effect during balanced magnetron sputtering deposition was studied and two new mechanisms which differentiate from the traditional bombardment and re-sputtering mechanisms were also proposed.