There are many useful applications for thin films. We desire to produce properties in a material that are often conflicting in nature if we use one homogeneous material. Semiconductor devices, for example, are fabricated on a thin layer deposited on a semiconductor substrate. The integrated electronic circuits depend on the confinement of electrical charges, which relies on the interfaces between different materials with different electronic properties. There are also many occasions when the properties demanded an engineering application involve features that are different for the surface than that are for the bulk. Depositing metal films and patterning them on the surface are relatively easy to secure electrical connection between semiconductor devices.