Nowadays, many of the things that surround us contain electronic stuffing. The advent of technologies that make it possible to place a device with huge computing capabilities on one small chip allows us to find indispensable helpers today. All smart electronic devices are controlled by microprocessors, which are, in essence, a large integrated circuit containing millions of transistors and other elements. But what about microprocessors, and indeed chips? How to get such bricks from a piece of silicon that makes up smart electronics.
Creating A Thin Base Plate.
Of all the chemical elements that processors are made of, the main one is silicon. Silicon is quite common in the earth’s crust and is a semiconductor. This means that depending on what impurities you add to it, it can become a conductor. Such properties of silicon make it possible to make a transistor switch, which underlies the principles of the processor. Modern processors contain millions of transistors.
At the first stage, plates are made on which the processor will be formed in the future. To do this, silicon extracted in the earth’s crust is subjected to purification. The resulting polysilicon is melted with a small number of active elements, such as arsenic, boron, phosphorus, and antimony, in a quartz crucible (a container that does not melt at high temperatures).
As soon as the temperature of the melt reaches the desired temperature, a seed from mono silicon is placed in it. The melt is slowly cooled, at this time, the growth of crystals begins around the placed seed. While crystal growth continues, the seed is slowly removed from the melt. To normalize the temperature fluctuations of the melt, it slowly rotates.
The melt temperature and the speed of seed extraction affect the diameter of the resulting crystalline silicon ingot, and the concentration of active impurities controls the properties of future plates that will be cut from this ingot. The process of growing crystalline silicon requires constant monitoring of the parameters of the rotating melt. Due to the surface tension of the liquid melt and the crystalline structure, the rotating crystalline silicon tends to a rounded shape.
This process can take several hours. For further use, the chemical purity of the grown crystalline silicon is very important. Since the ends of the obtained ingot can change their structure, they are cut off due to annealing at high temperature, in which the process takes place.
Next, the ingot is cut into plates with a thickness of one, two millimeters. The edges of the plates are rounded to prevent further chips and cracking. These plates are then sanded mechanically and chemically to obtain a flat mirror surface. The resulting plates are heated to remove any residual stress in them. After ultrafine surface control on a laser installation, the plates are ready for the formation of an electronic structure on them.
Creation Of Electronic Structure.
The creation of an electronic structure on the surface of silicon wafers is most often done by etching the surface of the wafer after applying a special masking layer.
An oxide layer is created on the surface of a silicon wafer under the influence of high temperatures. A layer of photoresist is applied to it, which is then irradiated with an ultraviolet light source through a special template containing the topography of the generated electronic structures.
A photoresist irradiated with ultraviolet light is fixed on a silicon wafer under its influence, a non-illuminated photoresist is washed off. Unprotected photoresist portions of the surface layer of silicon oxide are etched with phosphoric acid. After etching is completed, the protective mask from the photoresist is removed from the surface of the plate.
So the plate becomes ready for applying the next layer forming the desired electronic structure or for welding the electrical terminals of the formed microcircuit. By creating layers based on silicon with impurities of various elements, it is possible to obtain surface areas with the required electronic conductivity. When silicon is doped with boron, we obtain the so-called whole p-conductivity of the layer, with the addition of phosphorus and arsenic, we can obtain electronic n-conductivity. The same processes are used to create oxide (insulating) sections of the layer or metal pads.
These processes are carried out in special “clean” rooms since the smallest impurity that gets on a silicon wafer can change the formed electronic structure. Workers in these jobs wear special suits and breathe through special filters. Nowadays, all these processes are trying to automate as much as possible to exclude human participation.
As soon as the plate is ready, each chip formed on it is tested and tested. Chips that fail the test are marked to exclude their further use. As a rule, worse chips are obtained at the edges of the plate. Chips from the center of platinum pass further tougher tests for use in military and industrial equipment. In the end, the plate is cut into individual chips. After that, all the chips recognized as suitable for further use are each placed in their case Read also Pubg lite for PC.
Since the costs of manufacturing electronic components, in this case, can be very high, such enterprises are usually located in regions with relatively cheap labor.