الدوائر المتكاملة - الالكترونيات .. الفيزياء

Integrated Circuits - Electronics .. Physics

Integrated Circuits

Since 1955, until now, the size of transistors and other electronic components of electronic circuits has decreased very significantly.

Today, they are placed inside molds so that they are difficult to separate from each other. They are called integrated circuits and it has become possible to manufacture more than a thousand electronic circuits, each of which consists of a number of components ranging between 20 and 30 components on a silicon chip with a diameter of no more than 2.5 cm and a thickness of 0.2 mm. These circuits are characterized by being durable, inexpensive and long-life, and they are capable of performing all electronic functions very quickly due to the proximity of their components to each other.

The process of manufacturing integrated circuits includes a series of masking and diffusion stages. Each mask consists of a number of spaces with specific shapes, then the impurities of the type - S - are spread inside a chip of silicon of the type - M, resulting in a layer of silicon dioxide that does not allow the spread of impurities of the type M except in the areas designated for them, then the masks are replaced with other masks of different shapes. The types - S and - M are spread in the parts designated for them as well. Finally, the entire chip is coated with a metal in which the connection points between the parts of the circuit are etched. As for the basic layer of silicon of the type M, it is designated to differentiate between the components of the circuit to reduce the value of interference between them.

Integrated circuits are of great importance in electronic computers, as the speed of the computer's operation is primarily related to the speed of movement of electrons, which are well available in the integrated circuit due to the close proximity of the elements that make it up.

(Stages of forming the integrated circuit)

It is worth noting that digital computers calculate only by ones and zeros (binary numbering), and that the representation of these two numbers is done through the presence or absence of current. The integrated circuits used in computers are called micro-logic elements, and are used to pass a special current or in punching operations, etc..

The simplest of these logic elements are the (and) circuit and the "or" circuit. The first is characterized by the fact that its output is zero unless there are electrical signals on all of its inputs. As for the second, its output has a value when there is a specific signal on one or more of its inputs. Based on these two circuits, more complex logic circuits were created.