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采用汞蒸汽等离子体阴极溅射技术,已同时在几种CdTe衬底上(总面积为20cm~2)外延生长了Cd_xHg_(1-x)Te薄膜。薄膜在加热到310℃的衬底上生成,其淀积速率为0.6μm.h(总厚度≤30μm)。采用不同的实验方法对薄膜的结晶学特性进行了分析,这些方法包括:反射X-射线形貌、衍射分布图的半值宽度(FWHM)测量、透射电子显微镜分析(TEM)和卢瑟福反向散射分析(RBS)。TEM法,摆动曲线和RBS的结果揭示出薄膜具有很高的结晶学质量(外延层内的位错密度接近10~4cm~(-2))。在4K和300K之间测量了Cd_xHg_(1-x)Te外延层的霍耳系数。衬底温度为285℃时淀积的外延层(镉的组分为0.23,厚度16μm),在77K测量的结果是:载流子浓度n大约为2.7×10.(16)cm~(-3);霍耳迁移率为64000cm~2·V~(-1·S~(-1)。当镉的组分为0,31时(外延层厚度为18μm),则得到n=1.6×10~(16)cm~(-3);霍耳迁移率为16000cm~2·V~(-1)·S~(-1)。淀积出来的外延膜在双温区炉子内的汞气氛中退火后,其电学性质得到改善。n型外延膜的电子迁移率提高到接近用非最佳退火参量得到的体材料的水平。
Using mercury vapor plasma sputtering, Cd_xHg_ (1-x) Te thin films have been epitaxially grown on several CdTe substrates at a total area of 20cm ~ 2. The film was formed on a substrate heated to 310 ° C at a deposition rate of 0.6 μm.h (total thickness ≤ 30 μm). The crystallographic properties of the films were analyzed using various experimental methods including: reflection X-ray topography, full width at half maximum (FWHM) measurements of diffraction patterns, transmission electron microscopy (TEM), and Rutherford's anti- Scattering Analysis (RBS). The results of the TEM method, the rocking curve and the RBS reveal that the film has a high crystallographic quality (the dislocation density in the epitaxial layer is close to 10-4 cm -2). The Hall coefficient of the Cd_xHg_ (1-x) Te epitaxial layer was measured between 4K and 300K. The epitaxial layer deposited at a substrate temperature of 285 ° C (composition of cadmium: 0.23, thickness: 16 μm) measured at 77K showed a carrier concentration n of about 2.7 × 10 (16) cm -3 ); Hall mobility is 64000cm ~ 2 · V ~ (-1 · S -1) .When the composition of cadmium is 0, 31 (the epitaxial layer thickness is 18μm), we get n = 1.6 × 10 ~ (16) cm ~ (-3), Hall mobility is 16000cm ~ 2 · V ~ (-1) · s ~ (-1) .The deposited epitaxial films are annealed in a mercury atmosphere in a dual temperature zone furnace The electrical properties are improved.The electron mobility of the n-type epitaxial film is increased to near the level of the bulk material obtained with non-optimal annealing parameters.