传感器表面磁控溅射Mg-Sn涂层组织及导电特性分析

Deposition and Characterization of Magnetron Sputtered Mg-Sn Coatings

采用磁控溅射的方法在传感器用单晶Si衬底上制备一层Mg-Sn涂层,实验测试研究溅射次数对其组织及导电特性的影响。研究结果表明:沉积涂层内形成了具有明显尺寸差异的颗粒,从而形成了粗糙的表面。随着溅射次数增加,Mg含量发生了逐渐降低的现象,Sn与O元素含量表现为逐渐升高的变化规律。随着溅射剥离时间的增加,Mg1s峰位从1286降低至1285 eV,表现为涂层深度增大后,Mg1s发生了峰位降低的现象。出现在沉积薄膜内的O主要是为了提高靶材的成型能力而加入一些有机物所产生的。各涂层都具有正的Hall系数,可以判断属于p型半导体。当涂层内Mg含量发生减小后,电导率也随之减小。当涂层内形成更少的Mg2Sn与更多的Sn之后,引起了载流子浓度的下降,引起迁移率的减小。

The Mg-Sn coatings were synthesized by magnetron co-sputtering of oxygen containing Mg-Sn and Mg targets on Si-substrate for fabrication of pyroelectric sensor.The effect of the sputtering cycles,wherein 210 s for Mg-Sn and 30 s for Mg, on the microstructures and electrical conductivity was investigated with X-ray diffraction,scanning electron microscopy and X-ray photoelectron spectroscopy and.The preliminary results show that the cycle-number had a major impact.To be specific,a decreasing depth-profile of Mg1s peak,from 1286 to 1285 eV,was observed;as the cycle-number increased from 2,000 to 6,000 cycles,the Sn-and O-contents increased and the Mg-content decreased,resulting in a decrease of the conductivity.Moreover,a decrease of Mg2Sn-content,accompanied by an increase of Sn-content,was found to decrease the mobility,because the carrier concentration decreased in the p-typed semiconducting Mg-Sn coatings.