钠钙玻璃上Mg2Si薄膜的制备及其电学性质

采用磁控溅射技术和退火工艺在钠钙玻璃衬底上制备了Mg_2Si半导体薄膜,研究了Mg膜厚度对Mg_2Si薄膜结构及其电学性质的影响。在钠钙玻璃上分别溅射两组相同厚度(175nm)的P-Si和N-Si膜,然后在其上溅射不同厚度Mg膜(240nm、256nm、272nm、288nm、304nm),低真空退火4h制备一系列Mg_2Si半导体薄膜。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、霍尔效应测试仪对Mg_2Si薄膜的晶体结构、表面形貌、电学性质进行表征与分析。结果表明:采用磁控溅射技术在钠钙玻璃衬底上成功制备出以Mg_2Si(220)为主的Mg_2Si薄膜。随着沉积Mg膜厚度的增加,Mg_2Si衍射峰逐渐增强,薄膜表面更连续,电阻率逐渐减小,霍尔迁移率逐渐降低,载流子浓度逐渐增加。此外,Si膜导电类型和Mg膜厚度共同影响Mg_2Si薄膜的导电类型。溅射N-Si膜时,Mg_2Si薄膜的导电类型随着Mg膜厚度的增加由P型转化为N型;溅射P-Si膜时,Mg_2Si薄膜的导电类型为P型。可以控制制备的Mg_2Si半导体薄膜的导电类型,这对Mg_2Si薄膜的器件开发有着重要的指导意义。

Fabrication and Electrical Properties of Mg2Si Films on Soda Lime Glass

Semiconducting Mg₂Si films were prepared by magnetron sputtering deposition and subsequent annealing on soda-lime glass substrates. The influences of Mg film thickness on the crystal structure and electrical properties of Mg₂Si films were investigated. P-Si and N-Si films with same thickness (175 nm) were deposited on different soda-lime glass substrates by magnetron sputtering, and then Mg films with different thicknesses (240 nm, 256 nm, 272 nm, 288 nm and 304 nm) were deposited on Si films. A series of Mg₂Si semiconductor films were prepared by low vacuum annealing for 4 h. The crystal structure, surface morphology and electrical properties of the obtained films were characterized and analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and Hall effect measurement system. The results show that Mg₂Si films with preferential growth of Mg₂Si (220) are prepared successfully by magnetron sputtering technique on soda-lime glass substrates, and that the diffraction peak intensity of obtained Mg₂Si films increases with the increase of thickness of Mg films on Si films. Meantime both the electrical resistivity and mobi-lity decrease, and carrier concentrations increase. The surfaces of the films become continuous with the increase of thickness of Mg films on Si films. Both the electrical conduction type of deposited Si films and the thickness of deposited Mg films affect the electrical conduction type of the obtained Mg₂Si films. When the N-type Si films are deposited firstly on substrates, the electrical conduction type of the obtained Mg₂Si films changes from P-type to N-type with the increase of the thickness of deposited Mg films on Si films. When the P-type Si films are deposited firstly on substrates, the electrical conduction type of the obtained Mg₂Si films becomes P-type. The electrical conduction type of the obtained Mg₂Si films can be controlled conveniently, which is beneficial to the device development of the Mg₂Si films.