Fabrication of PbTiO3/Pt/Yttria Stabilized ZrO2 Heteroepitaxial Films on Si Substrate

Fabrication of PbTiO 3 /Pt/yttria-stabilized ZrO 2 (YSZ) heteroepitaxial films on Si substrate was investigated with the aim of applying them to electric devices such as integrated infrared sensors and ferroelectric random-access memories (FRAMs). First, a (100)YSZ buffer layer was epitaxially grown on a (100)Si substrate using reactive electron-beam evaporation. In this process, a metallic Zr film was deposited before YSZ deposition in order to prevent a Si substrate surface from oxidizing. Then, Pt film was sputtered on the buffer layer. A rough YSZ surface attained by slightly etching the Si substrate surface is found to be essential to obtain (100)-oriented Pt films, while (111)-oriented Pt films were obtained on a smooth YSZ surface. This indicates that we can control the orientation of Pt film by controlling the morphology of the YSZ surface. Lastly, a (001)-oriented PbTiO 3 film was epitaxially grown on (100)Pt/(100)YSZ/(100)Si using metalorganic chemical vapor deposition (MOCVD).