Microelectronics – what is it
Microelectronics is a field of electronics concerned with the creation of micro-miniature assemblies, blocks, and devices. Electronic clocks, calculators and other small-sized devices are well known to all. But not everyone knows that their micro-miniature manufacture became possible only in the early 1960s, with the emergence of microelectronics.
The rapid pace of its development indicates a new stage in the scientific and technological revolution. To get an idea of the challenges and opportunities of microelectronics, let’s take a brief look at the history of electronics. At the beginning of the XX century, after the invention of the tube diode by Englishman J. Fleming in 1904 and the three-electrode tube by American L. De Forest in 1906, scientists began to develop various electronic devices (radio receivers, oscilloscopes, amplifiers, etc.).
Electronic equipment was created from separate prefabricated elements – electronic tubes, resistors, capacitors, etc., which were connected with each other by electrical wires by soldering or welding. Production of such equipment was labor-intensive and expensive, while the electronic devices themselves were bulky, unreliable, and consumed a lot of energy. One of the challenges of electronics was to overcome these disadvantages.
Using the achievements of solid state physics, the American inventors W. Shockley, W. Bratstein and J. Bardin created the semiconductor device – the transistor (see Semiconductors) in 1948, making a revolution in electronics. Since that time, electronic devices have been made of individual modules. Each module (4-20 cm3 in volume), assembled from several prefabricated elements, performed a specific function (amplification, switching, memory, etc.).
Such modules were used to assemble complex electronic equipment, which improved reliability, significantly reduced size and power consumption. However, both this equipment itself and the way of its production soon failed to meet the rate of science and technology development. Further progress in electronics was related to the development of microelectronics, based on the use of integrated circuits. An integrated circuit is a micro-miniature electronic device, the elements of which are inseparably linked structurally and electrically.
According to the method of combining (integrating) elements, there are semiconductor, film and hybrid integrated circuits (ICs). Semiconductor ICs are made from particularly pure semiconductor materials (silicon, germanium) in which the crystal structure is rearranged so that individual areas of the crystal become elements of a complex system. A small plate of crystal material about 1 mm2 in size becomes a sophisticated electronic device, replacing a radiotechnical unit of 50-100 and more ordinary parts.
Integrated circuits have been developed that contain hundreds and thousands of elements in a single crystal, so-called large integrated circuits. (LICS). Film integrated circuits are made by depositing various materials in the form of thin films on a heated to a certain temperature polished substrate (usually ceramic). The materials used include aluminum, titanium, barium titanate, tin oxide, etc.
In order to obtain integrated circuits with certain functions, thin-film multilayer structures are created by depositing materials with the desired properties on a substrate through various stencils (templates). In such structures, one of the layers contains microresistors, another contains microcapacitors, and several subsequent layers contain current conductors and other elements. All elements in the layers have interconnections between them, characteristic of specific radio engineering devices.
Film and semiconductor elements are used in hybrid integrated circuits, complementing each other in radioelectronic complexes. Problems of design, manufacture and application of integrated circuits are dealt with in a special field of electronics – integrated electronics. All processes of their manufacture, which require high-quality materials and precise equipment, are fully automated.
Integrated circuits are widely used in electronic computing machines, control and measurement equipment, communications equipment, consumer electronic devices. New opportunities in solving microelectronic problems of automatic control of technological processes, information processing, improvement of computing machinery have opened up in connection with the development and application of microprocessors.
Microprocessor, manufactured on one chip or on several LSIs, contains all basic devices of computers. Microprocessors served as the basis for the creation of various domestic and industrial computers – from personal computers to supercomputers. Hybrid ICs were created, containing logical and powerful high-voltage elements on one chip, which are used, in particular, in electric motor regulators.