How to create chips. Chips. Microcham production technology

The appearance of integrated chips produced a real technological revolution in electronics and the IT industry. It would seem that only a few decades ago for the simplest electronic computing, huge lamp computers were used, which served in several rooms and even whole buildings.

These computers contained many thousands of electronic lamps, which required for their work of colossal electrical capacity and special Systems cooling. Today they replaced computers on integrated chips.

In fact, the integral chip is an assembly of many semiconductor components of the microscopic size placed on the substrate and packed in the miniature case.

One modern chip with a size with human nail may contain within several millions of diodes, transistors, resistors, connective conductors and other components, which in the olden times would require a rather large hangar space for its placement.

For examples, it is not necessary to go far, the processor I7, for example, contains less than three square centimeters on an area of \u200b\u200bmore than three billion transistors! And this is not the limit.

Next, now consider the basis of the microcircuit creation process. The microcircuit is formed according to planar (surface) technology by lithography. This means that it is as if grown from a semiconductor on a silicon substrate.

The first thing is prepared by a thin silicon plate, which is obtained from silicon monocrystal by cutting from a cylindrical billet using a diamond spraying disc. Plate polish B. special conditionsTo avoid contacting her pollution and any dust.

After that, the plate is oxidized - oxygen affects it at a temperature of about 1000 ° C in order to obtain a layer of durable dielectric film of silicon dioxide thickness into the required number of micron on its surface. The thickness of the oxide-produced layer depends on the time of exposure to oxygen, as well as on the temperature of the substrate during oxidation.

Next, a photoresist is applied on a silicon dioxide layer - a photosensitive composition, which is dissolved after irradiation in a certain chemical. The stencil is put on the photoresist - photoshames with transparent and opaque areas. Then the plate with the photoresist applied to it is exposed - extinguish the source of ultraviolet radiation.

As a result of the exposure, the part of the photoresist, which was under the transparent sections of the photo masklon, changes its chemical properties, and now it can be easily removed along with silicon dioxide under it with special chemicals, with a plasma or in another way - this is called etching. At the end of the etching, the plates unprotected by the photoresist (illuminated) turns out to be purified from the beam photoresist and then from silicon dioxide.

After etching and cleansing from the unfounded photoresist of those places of substrate, on which silicon dioxide remained, proceed to epitaxes - the layers of the desired substance with one atom thick are applied to the silicon plate. Such layers can be applied as much as necessary. Next, the plate is heated and the diffusion of ions of certain substances is carried out to obtain P and N-area. As an acceptor use boron, and as donors - arsenic and phosphorus.

In the completion of the process, metallization by aluminum, nickel or gold is made to obtain thin conductive films that will act as connecting conductors for the substrates grown on the previous stages of transistors, diodes, resistors, etc. In the same way, contact plates on a printed circuit board.

Panyushkin V.V.

("Hij", 2014, №4)

Production of tiny chips giving life laptop is one of the most complex and sophisticated. It consists of more than three hundred operations, and one the production cycle can last up to several weeks. What does this process look like in a simplified form?

Apply a layer of silicon

The first thing to be done is to create on the surface of a silicon substrate with a diameter of 30 cm an additional layer. Silicon atoms increase on the substrate by the epitaxy method: they gradually settle on the silicon surface from the gas phase. The process proceeds in vacuo, there is nothing superfluous here, so as a result, the finest silicon layer is formed on the surface with the same crystal structure as a silicon substrate, only even cleaner. In other words, we get a somewhat improved substrate.

Apply a protective layer

Now on the surface of the substrate it is necessary to create a protective layer, that is, simply oxidizing it, so that the finest film of SiO 2 silicon oxide is formed.

Its function is very important: the oxide film will continue to interfere with the electric current to flow from the plate. By the way, in recently, instead of traditional silicon dioxide, Intel began to use a high-k-dielectric based on oxides and hafnium silicates, which are higher compared to silicon oxide dielectric constant k. The High-k layer of the dielectric makes about two times thicker than the layer of conventional SiO 2, due to the narrowing of the adjacent areas, but due to the comparable tank, the leakage current can be reduced a hundred times. This allows you to continue miniaturization of processors.

Apply a layer of photoresist

On the protective layer of silicon oxide, you must apply a photoresist - polymeric materialwhose properties are changed under the influence of radiation. Most often, polymethacrylates, arylsulfoockets and phenyl formaldehyde resins are acting in this role, which are destroyed by ultraviolet (this process is called photovography). They are applied to a rotating substrate, spraying with its aerosol of said substance. In principle, it is also possible to use an electron beam (electron-ray lithography) or soft X-ray radiation (X-ray lithography), selecting the corresponding sensitive substances to them. But we will look at the traditional process of photolithography.

We will irradiate ultraviolet

Now the substrate is ready to contact with ultraviolet, but not direct, but through an intermediary - a photomask, which plays the role of the stencil. In fact, the photomask is a drawing of a future chip, only increased several times. To proper it to the surface of the substrate, special lenses that reduce the image are used. This gives striking clarity and projection accuracy.

Ultraviolet, passing through the mask and lenses, projects the image of the future scheme to the substrate. On Footmascus, future working sections of the integral chip are transparent to ultraviolet, and passive areas - on the contrary. In those places on the substrate where active structural elements should be located, the irradiation destroys the photoresist. And on passive areas, the destruction does not occur, because there is a ultraviolet, it does not fall: he is stencils stencil. The chemical reaction that occurs in the layer under the influence of ultraviolet, is very similar to the reaction in the film occurring during photographing. The destroyed photoresist is easily dissolved, so remove the decomposition products from the substrate is easy. By the way, to create one processor it is necessary to 30 different photo masks, therefore the step is repeated as the layers apply to each other.

Trestim.

So, the drawing of the future scheme with all elements of size up to several nanometers is moved to the surface of the substrate. Areas where the protective layer collapsed, now must be etched. In this case, passive areas will not suffer because they are protected by a polymer layer of photoresist, which has not collapsed in the previous stage. The irradiated areas are etched by either chemical reagents or physical methods.

In the first case, to destroy silicon dioxide layer, hydrofluoric acid and ammonium fluoride are used. Liquid etching is a good thing, but there is a problem: the liquid storing the leakage under the resist layer on the adjacent passive areas. And as a result, the part of the etched pattern in size turns out to be greater than the mask is provided. Therefore, a dry physical method is preferable - reactive ion etching by plasma. For each material subjected to dry etching, the corresponding jet gas is selected. So, silicon and its compounds are etched by chlorine and fluorine-containing plasma (CCl 4 + Cl 2 + Ar, CLF 3 + Cl 2, CHF 3, CF 4 + H 2, C 2 F 6). True, dry etching also has a disadvantage - a smaller selectivity compared to liquid etching. Fortunately, this case has a universal method - ion-radiant etching. It is suitable for any material or combination of materials and has the highest among all methods of etching by resolution, allowing you to obtain elements with less than 10 nm.

Alloy

Now the time of ion implantation has come. It allows you to implement almost any chemical elements in required quantity On a given depth on the treated areas where a silicon substrate was exposed. The purpose of this operation is to change the type of conductivity and the concentration of carriers in the semiconductor volume to obtain the desired properties, for example, the required smoothness of the P-N transition. The most common alloying impurities for silicon is phosphorus, arsenic (provide an electronic conductivity of N-type) and Bor (p-type hole conductivity). Ions of the implantable elements in the form of plasma accelerate to high speeds Electromagnetic field and bombard with them the substrate. Energetic ions penetrate unprotected areas, plunging into a sample to a depth of several nanometers to several micrometers.

After the introduction of ions, the photoresistive layer is removed, and the resulting design is annealed at high temperature so that the disturbed structure of the semiconductor and the ligand ions has occupied the nodes of the crystal lattice. In general, the first layer of transistors is ready.

We make windows

On top of the resulting transistor, it is necessary to apply an insulating layer on which three "windows" are etched by the same method of photolithography. Through them, contacts with other transistors will be created.

We apply metal

Now the entire surface of the plate is covered with a layer of copper with a vacuum spraying. Copper ions pass from a positive electrode (anode) to a negative electrode (cathode), whose role is played by the substrate, and sit on it, filling the windows created by etching. Then the surface is polished, removing excess copper. Metal is applied in several stages to create interconnections (they can be represented as connecting wires) between individual transistors.

The layout of such interconnections is determined by the microprocessor architecture. Thus, in modern processors, there are connections between about 20 layers forming a complex three-dimensional scheme. The number of layers may vary depending on the type of processor.

Test

Finally, our record is ready for testing. The main controller here is the probe heads on the installations of automatic labeling of plates. By touching the plates, they measure electrical parameters. If something is wrong - marked crystals, which are then discarded. By the way, a crystal in microelectronics is called a single integral chip of arbitrary complexity placed on the semiconductor plate.

Draw

Next, the plates are separated into single crystals. On one substrate with a diameter of 30 cm, about 150 microcircuits are approximately 2x2 cm in size. For separation, the plate is either caught with a diamond cutter or a laser beam, and then they are cleaned over ready-made cuts, or immediately cut the diamond disk.

Processor is ready!

After that, connect the contact pad to ensure the connection of the processor with the rest of the system, the crystal, and the cover, which takes place heat from the crystal to the cooler.

The processor is ready! According to mine (probably very inaccurate), the predictions for the manufacture of one modern processor, such, for example, as a quad-core Intel Core i7, it is necessary to spend about a month of work of the ultra-modern factory and 150 kWh of electricity. In this case, the mass of silicon and chemicals consumed on one crystal is calculated with maximum grams, copper - shares of grams, gold for contacts - milligrams, and ligands like phosphorus, arsenic, boron - and less.

Slika

For those who risk becoming confused in substrates, chips, processors and crystals, give a small word dictionary.

Substrate - Round monocrystalline silicon plate with a diameter of 10 to 45 cm, which grows semiconductor chips by epitaxy.

Crystal, Chip, Integrated Chip - not related to other part of the substrate with a multilayer transistor system grown on it, connected by copper contacts. Later is used as the main part of the microprocessor.

Ligand (alloying admixtures) - In the case of semiconductor materials, the substance whose atoms are embedded in the silicon crystal lattice, changing its conductivity.

Processor, microprocessor - Central computing element of modern computers. It consists of a crystal placed on the contact pad and a closed heat sink lid.

Footmascus - Translucent plate with a pattern, through which the light passes when the photoresist is irradiated.

Photoresist - Polymer photosensitive material, whose properties, such as solubility, change after exposure to a certain type of radiation.

Epitaxy - Better-oriented growth of one crystal on the surface of another. In this case, the word "crystal" is used in its main value. There are many methods for producing ordered crystals based on epitaxial buildings.

Without which it is difficult to present existence modern man? Of course, without modern technology. Some things so entered our lives, so come. Internet, TV, microwaves, refrigerators, washing machines - without it it is difficult to imagine modern world And, of course, herself in it.

What makes almost the whole of today's technique for a truly useful and necessary?

What an invention provided progress the broadest opportunities?

One of the most essential discoveries of a person is a microcircuit production technology.

Thanks to her, modern technique has such small sizes. It is compact and convenient.

We all know that a huge number of things consisting of microcircuits can fit in the house. Many of them are placed in pocket pockets and have a slight weight.

Thorny path

To achieve results and get a chip, scientists have worked for many years. The initial schemes had the most huge dimensions on the current standards, they were larger and heavier than the refrigerator, at Ω that the modern refrigerator does not consist of complex and tangled schemes. Nothing like this! It has one small, but superior in its utility old and bulky. The discovery was produced by Furior, giving impetus to the further development of science and technology, the breakthrough was made. Equipment for the production of microcircuits is released.

Equipment

The production of microcircuits is a difficult task, but the benefit of a person has those technologies that simplify the task of production. Despite the complexity, a huge number of microcircuits around the world is produced daily. They are constantly improving, acquire new features and increased characteristics. How do these small but smart systems appear? This helps the equipment for the production of microcircuits, which, actually, is referred further.

When creating microcircuits, electrochemical deposition systems, wash chambers, laboratory oxidative chambers, copper electrodeposition systems, photolithographic and other technological equipment are used.

Photolithographic equipment is the most expensive and accurate in mechanical engineering. It is responsible for creating images on a silicon substrate to generate an intended microcircuit topology. On the thin layer The material is applied a photoresist, subsequently subjected to the irradiation of the photo mask and the optical system. During the operation of the equipment there is a decrease in the size of the pattern of pattern.

In positioning systems, a linear motor and a laser interferometer, having frequently feedback plays a leading role. But, for example, in the technology developed by the Moscow Laboratory "Amphora", there is no such connection. This domestic equipment has a more accurate movement and smooth repetition on both sides, which eliminates the possibility of the backlash.

Special filters protect the mask from heating emanating from the deep ultraviolet area, carrying the temperature for 1000 degrees over long months of work.

Low-energy ions are assigned to multilayer coatings. Previously, this work was performed solely by the method of magnetron sputtering.

Microcham production technology

The whole process of creating semiconductor crystals begins. The most relevant is silicon. The thin semiconductor plate is obscured before the occurrence of a mirror image in it. In the future, a mandatory stage of creation will be photolithography with the use of ultraviolet when applying a picture. This helps the machine for the production of microcircuits.

What is a microcircuit? This is such a multi-layer pate of thin silicon plates. Each of them causes a certain drawing. This image is created at the stage of photolithography. Plates are gently placed in special equipment with a temperature of more than 700 degrees. After firing, they are washed with water.

The process of creating a multilayer plate takes up to two weeks. Photolithography is carried out a numerous number of times until the desired result is reached.

Creating microcircuits in Russia

Domestic scientists in this industry also have their own technologies for the production of digital microcircuits. The plants of the corresponding profile function across the country. At the exit specifications Not much inferior to competitors from other countries. Preference to Russian chips in several states. All thanks to a fixed price, which is less than that of Western manufacturers.

Required components of high-quality chip

Microcircuits are created in rooms equipped with systems that control air purity. At the same time, special filters collect information and handle air, thereby making it cleaner than in operating rooms. Employees in production are special protective overalls, which are often equipped with an internal oxygen supply system.

Microcircuit production is profitable business. Good specialists in this area are always in demand. Almost all electronics operates due to chip. They are equipped with modern cars. Spacecraft could not function without the presence of microcircuits. The process of obtaining is regularly improved, the quality improves, the possibilities are expanding, the suitability period is growing. Microcircuits will be relevant over long dozens, and even hundreds of years. Their main task is to benefit on Earth and outside it.

Chip

Modern integrated chips designed for surface mounting.

Soviet and foreign digital microcircuits.

Integral ENGL. INTEGRATED CIRCUIT, IC, Microcircuit, Microchip, Silicon Chip, OR CHIP), ( micro)scheme (IP, IS, M / CX), chip, microchip (eng. chip. - Slug, chip, chip) - a microelectronic device - an electronic circuit of arbitrary complexity, made on a semiconductor crystal (or film) and placed in an unintended body. Often under integrated circuit (IP) understand the actual crystal or film with an electronic circuit, and under microcham (MS) - ICs enclosed in the case. At the same time, the expression "chip component" means "components for surface mounting" in contrast to the components for the traditional soldering in the opening on the board. Therefore, it is more correct to say "chip chip", meaning a microcircuit for surface editing. Currently (year) Most of the microcircuits are manufactured in the housings for surface mounting.

History

The invention of the microcircuit began with the study of the properties of thin oxide films that appear in the effect of poor electrical conductivity at small electrical stresses. The problem was that in the place of contacting two metals did not occur electrical contact or he had polar properties. Deep studies of this phenomenon led to the discovery of diodes and later transistors and integrated circuits.

Design levels

  • Physical - methods for implementing one transistor (or small group) in the form of doped zones on a crystal.
  • Electric - conceptual electrical diagram (transistors, condensers, resistors, etc.).
  • Logical - logical scheme (logical inverters, elements or non, and not, etc.).
  • Schedural and systemotechnical level - circuit and systemotechnical schemes (triggers, comparators, encoders, decoders, aluminum, etc.).
  • Topological - topological photosales for production.
  • Program level (for microcontrollers and microprocessors) - assembler commands for a programmer.

Currently, most of the integrated circuits are developed using CAD, which allow you to automate and significantly accelerate the process of obtaining topological photos.

Classification

The degree of integration

Purpose

The integrated chip may have a complete, as complex, functional - up to a whole microcomputer (single-chip microcomputer).

Analog schemes

  • Signal generators
  • Analog multipliers
  • Analog Attenuators and Adjustable Amplifiers
  • Stabilizers of power sources
  • Pulse Power Supply Control Microcircuits
  • Signal converters
  • Synchronization schemes
  • Various sensors (temperatures, etc.)

Digital circuits

  • Logic elements
  • Buffer transducers
  • Memory modules
  • (Micro) processors (including CPUs in the computer)
  • Solidary microcomputers
  • FPGA - programmable logical integrated circuits

Digital integral chips have a number of advantages compared to analog:

  • Reduced power consumption It is associated with the use of pulsed electrical signals in digital electronics. When receiving and converting such signals, active elements of electronic devices (transistors) operate in the "key" mode, that is, the transistor is either "open" - which corresponds to the high-level signal (1), or "closed" - (0), in the first case There is no voltage drop in the transistor, in the second - it does not go through it. In both cases, energy consumption is close to 0, unlike analog devices, in which most of the time transistors are in an intermediate (resistive) state.
  • High noise immunity Digital devices are associated with a large difference of high signals (for example, 2.5 - 5 V) and low (0- 0.5 V) level. The error is possible with such interference when the high level is perceived as low and vice versa, which is probably not enough. In addition, in digital devices it is possible to apply special codes to correct errors.
  • The great difference between high and low level signals and a fairly wide interval of their permissible changes makes digital technique insensitive By inevitable in the integrated technology, the variation of elements parameters, eliminates the need to select and configure digital devices.

The modern world is so computerized that our life is practically not presented without the existence of electronic devices, accompanying us in all areas of our life and activity.
And progress does not stand still, but continues to continuously improve: devices decrease and becoming more powerful, more capacitive and more productive. The basis of this process is the technology microcham production, which is in a simplified embodiment, a compound of several without cabinet diodes, triododes, transistors, resistors and other active electronic components (sometimes their number in one microcircuit reaches several million), combined with one diagram.

Semiconductor crystals (silicon, germanium, hafnia oxide, gallium arsenide) - are the basis of production of all chips. All element and inter-element connections are performed on them. The most common of them is silicon, as it is in its physicochemical qualities, the most suitable for these purposes, the semiconductor. The fact is that semiconductor materials belong to the class with electrical conductivity between conductors and insulators. And they can act as conductors and dielectrics depending on the content of other chemical impurities in them.

Microcircuits are created By consistently creating different layers on a thin semiconductor plate, which are pre-polished and communicated with mechanical or chemical methods to a mirror gloss. The surface must necessarily be completely smooth at the atomic level.

Video stages of microcircuit production:

When forming the layers, due to the fact that the drawings applied to the surface of the plate are so small, so the material forms subsequently the drawing is precipitated immediately to the entire surface, and then remove unnecessary using the process of photolithography.

Photolithography is one of the main stages microcircuit production And something resembles the production of photography. A special light-sensitive material (photoresist) is applied to the surface of the previously applied material (photoresist), then it is dried. Next, through a special photo mask on the surface of the layer, the desired picture is projected. Under the influence of ultraviolet, individual sections of the photoresist change their properties - fastens, so unwill areas are subsequently removed. This method of drawing is so effective for its accuracy, which will still be used for a long time.

This is followed by the process of electrical connection between transistors in chips, combining transistors into separate cells, and cells into separate blocks. Interconnections are created in several metal layers of completed chip. As materials in the production of layers, copper is mainly used, and gold is used for highly productive schemes. The number of layers of electrical connections depends on the power and performance of the microcircuit being created - the more powerful volume contains these layers in itself.

Thus, the complex three-dimensional structure of the electron microcircuit is a thick of several microns. The electronic circuit is then coated with a layer of dielectric material with a thickness of several tens of microns. It only discovers only the contact pads through which the power and electrical signals from outside are subsequently served in chip. The slope is attached to a flint plate thick hundreds of microns.

Upon completion of the crystal production process on the plate, each separately is tested. Then each chip is packaged into its housing, with which it appears the ability to connect it to other devices. Undoubtedly the type of packaging depends on the purpose of the chip and how to use it. Packed chips pass the main stage of the stress test: the effect of temperatures, humidity, electricity. And already according to the results of the test, they are rejected, sorted and classified according to specifications.


It is important in the process of producing micro-level details, which chips are the perfect cleanliness of the premises for production. Therefore, specially equipped rooms are used to ensure perfect purity, which are primarily completely sealed, equipped with microfilters for air purification, personnel working in these rooms have overalls that impede penetration of any microparticles there. In addition, these rooms provide a certain humidity, air temperature, they are built on fundamentals with protection against vibrations.

Video - excursion to the plant where chips are produced:

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