Technology of semiconductor devices and integrated circuits. Subject; Technologies of preparation of integrated circuits. by: 143-20 EA student Sardor Jo`tanboyev integrated circuit (IC), microcircuit or chip - very compact (microminiature) electronic device. Its elements (diodes, transistors, resistors, capacitors, etc.) are structurally, technologically and electrically interconnected (united) and very densely arranged. It is intended for receiving and processing information in the form of continuous or discrete (continuous) electrical and optical signals. The integrated circuit is divided into the following types: according to the method of combining elements (integration) - integral (monolithic) and hybrid (composite) (used with suspended discrete electronic devices) circuits; according to the type of processed signals - digital and analog schemes; The number of elements in IS is divided into small (N<102), medium (N=102-103), large (N=W-104) and very large (N>104) schemes according to N (level of integration). The integrated circuit is used in electronic computing machines, control and measuring devices, communication equipment and other fields.
Manufacturing technology of semiconductor microcircuits - Depending on the type of semiconductor technology (localization and lithography, vacuum deposition and galvanic deposition, epitaxy, diffusion, alloying and etching) the capacitance or active resistance or the different conductivities equivalent to different semiconductor devices areas with are taken. By changing the concentration of impurities, it is possible to obtain a multilayer structure that repeats the given electrical circuit in the crystal
- Currently, group methods of semiconductor integrated circuit manufacturing are used, which allows to obtain several hundred microcircuit blanks in one technological cycle. The most common is the group planar method, which consists in the fact that the elements of microcircuits (capacitors, resistors, diodes and transistors) are located in the same plane or on the same side of the substrate.
- The main technological processes used in the production of semiconductor microcircuits (thermal oxidation, lithography, epitaxy, diffusion and ion doping).
Currently, semiconductor elements and components of microcircuits are obtained by three methods: epitaxy, thermal diffusion and ion doping - Epitaxy is a process of growing layers with an ordered crystalline structure by implementing the directional effect of the substrate crystal.
- Thermal diffusion is widely used to introduce dopants into semiconductor wafers or epitaxial layers grown on them to obtain semiconductor elements of the reverse conductivity type or elements with lower electrical resistance than the original material. In the first case, for example, emitters are taken, and in the second, collectors.
- The ion doping process is determined by the initial kinetic energy of the ions in the semiconductor and is carried out in two stages.
The main technological stages of obtaining semiconductor microcircuits According to the method of creating film compositions, microcircuits are divided into two classes - hybrid integrated circuits (GIS) and semiconductor integrated circuits (IC). - Hybrid integrated circuits are microminiature electronic devices, the elements of which are structurally, technologically and electrically integrally connected on the surface of a dielectric (glass, ceramic) substrate. In GIS technology, passive elements (resistors, conductors, contact pads, capacitors, dielectric and insulating layers) are produced in one technological cycle in the form of metal and dielectric films on the substrate surface. Active components (diodes, transistors), if necessary, microminiature discrete passive components (capacitors, inductors, etc.) are installed on the surface of the substrate and connected to other elements.
- Semiconductor (solid-state) integrated circuits are produced by purposefully changing the material properties of an impurity-coated semiconductor substrate.
- The process of creating a multilayer plate takes up to two weeks. Photolithography is performed several times until the desired result is achieved.
- Microcircuits are created in rooms equipped with air cleanliness control systems. At all stages of creation, special filters collect information and process the air, making it cleaner than operating rooms. Workers in production often wear special protective overalls equipped with an internal oxygen supply system.
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