tailieunhanh - Crystalline Silicon Properties and Uses Part 3

Tham khảo tài liệu 'crystalline silicon properties and uses part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Study of SiO2 Si Interface by Surface Techniques 39 Arbitary units 158 152 Binding Energy eV Arbitary units 108 100 Binding Energy eV Fig. 15. XPS signal for Si-2p right and Si-2s left for SiO2 Si blue SiC 2 quartz- green SiO2 ion etching 1 red SiO2 ion etching 2 turquoise SiO2 ion etching 3 olive For a better observation of the amorphous surface layer the cross-section specimen has been oriented in the microscope along the 110 zone axis as shown in the Selected Area Electron Diffraction pattern inserted in Fig. 16 a . This way the strongly diffracting crystalline object the Si wafer shows a strong dark contrast allowing to clearly seeing the interface between the crystalline Si and the amorphous layer on the surface. In the thicker areas of the TEM specimen the assembling resin has not been removed during the ion milling preparation stage Fig. 16 a . Here the limit between the amorphous SiO2 layer and the amorphous assembling resin is rather difficult to notice. However the contrast difference between the two amorphous materials allows one to measure the thickness of the SiO2 layer. One can notice the roughness of the crystalline Si wafer and the amorphous band with a rather constant thickness about nm running along the surface. In the thinner areas of the specimen Fig. 16 b the assembling resin has been removed by ion milling while a band of amorphous material with the same thickness nm running parallel to the crystalline surface is still observable. We conclude therefore that the thickness of the amorphous Si layer on top of the Si 001 wafer measured by TEM is nm. 40 Crystalline Silicon - Properties and Uses a b Fig. 16. a Cross-section TEM image of the Si surface in a thicker area of the specimen where the assembling resin is still visible after the ion milling. Inset shows the b Cross-section TEM image of the Si surface in a thinner of the specimen where the assembling resin has been removed by ion milling. As it was stated in previous