Semiconductor devices, thin-film technology

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

Various techniques are used for the fabrication of semiconductor sensors. Conductance sensors from structurized sintered polycrystalline ceramics can be produced by thick- or thin-film technology. Chemically sensitive materials in the form of single crystals or whiskers can be attached to electrodes by thin- or thick-film techniques as well. Mass production of sensors requires that the resulting devices be characterized by a defined level of conductance. For example, the conductance of polycrystalline Sn02 can be adjusted by subsequent thermal treatment >800°C under a controlled partial pressure of oxygen. Another approach to defined conductance involves doping the semiconductor with antimony or fluorine. The reproducibility and stability of a sensor signal... 

Kim H (2003) Atomic layer deposition of metal and nitride thin films. Current research efforts and applications for semiconductor device processing. Journal of Vacuum Science Technology B 21(6), 2231-2261... 

A.2 Semiconductor Device Fabrication. In this section we investigate the gas-phase synthesis of compounds, primarily semiconductors, that are preferentially deposited on a surface to form a layer called a thin film. This technology can be used to form structural and protective layers of materials described in the previous section, but is used primarily to form thin films from semiconductor materials for electronic devices. Recall from Figure 6.99, for example, that most semiconductor devices are made from layers of appropriately doped compounds. In order to fabricate these devices at ever smaller scales, the layers must be formed in a carefully controlled manner. This... 

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