A few years ago, Intel introduced a step-by-step process for the production of microprocessors: from sand to the final product. In fact, the manufacturing process of semiconductor elements looks truly amazing.
Step 1. Sand
Silicon, which makes up about 25 percent of all chemical elements in the earth's crust by total weight, is the second most abundant after oxygen. Sand has a high percentage of silicon dioxide (SiO 2 ), which is the main ingredient not only for the production of Intel processors, but also for semiconductor production in general.
Molten silicon
The substance is purified in several stages until silicon of the semiconductor purity used in semiconductors is obtained. Ultimately, it comes in the form of single-crystal ingots with a diameter of about 300 millimeters (12 inches). Previously, ingots had a diameter of 200 millimeters (8 inches), and in the distant 1970 - even less - 50 millimeters (2 inches).
At this level of processor production, after purification, the crystal purity is one impurity atom per billion silicon atoms. The weight of the ingot is 100 kilograms.
Step 3. Ingot Cutting
The ingot is cut into a very thin saw into separate slices called substrates. Each of them is subsequently polished to obtain a defect-free mirror-smooth surface. It is on this smooth surface that tiny copper wires will subsequently be applied.
Exposure of the photoresist layer
A photoresistive liquid is poured onto a substrate rotating at a high speed (the same materials are used in traditional photography). Upon rotation, a thin and uniform resistive layer forms on the entire surface of the substrate.
An ultraviolet laser through masks and a lens acts on the surface of the substrate, forming small illuminated ultraviolet lines on it. A lens makes a focused image 4 times smaller than a mask. Everywhere where ultraviolet lines act on the resistive layer, a chemical reaction occurs, as a result of which these areas become soluble.
Step 5. Etching
The soluble photoresistive material is then completely dissolved with a chemical solvent. Thus, a chemical etchant is used to partially dissolve or etch a small amount of polished semiconductor material (substrate). The rest of the photoresistive material is removed by a similar washing process, revealing (exhibiting) the etched surface of the substrate.
Layer formation
To create tiny copper wires that will ultimately transfer electricity to / from various connectors, additional photoresists (photosensitive materials) are added, which are also washed and exposed. Subsequently, an ion-doping process is performed to add impurities and protect the deposition sites of copper ions from copper sulphate during the electroplating process.
At various stages of these processor manufacturing processes, additional materials are added that are etched and polished. This process is repeated 6 times to form 6 layers.
The final product looks like a grid of many microscopic copper strips that conduct electricity. Some of them are connected with others, and some are located at a certain distance from others. But they are all used to realize one goal - to transfer electrons. In other words, they are designed to provide the so-called “useful work” (for example, adding two numbers at the highest possible speed, which is the essence of the computational model today).
Multilevel processing is repeated on each individual small portion of the surface of the substrate on which the chips will be made. Including such areas include those that are partially located outside the substrate.
Step 7. Testing
As soon as all metal layers are deposited and all transistors are created, the time comes for the next stage of production of Intel processors - testing. A device with many pins is located at the top of the chip. Many microscopic wires are attached to it. Each such wiring has an electrical connection to the chip.
To reproduce the operation of the chip, a sequence of test signals is transmitted to it. During testing, not only traditional computing abilities are checked, but also internal diagnostics is performed with determination of voltage values, cascade sequences and other functions. The chip response in the form of a test result is stored in a database specially allocated for a given section of the substrate. This process is repeated for each portion of the substrate.
Plate cutting
A very small saw with a diamond tip is used to cut the plates. The database filled in at the previous stage is used to determine which chips cut from the substrate are saved and which are discarded.
Step 9. Enclosure in the enclosure
All working plates are placed in physical enclosures. Despite the fact that the plates were previously tested and it was decided that they work correctly, this does not mean that they are good processors.
The enclosure process means placing a silicon crystal in the substrate material, to which miniature gold wires are connected to the contacts or the array of ball terminals. An array of ball terminals can be found on the back of the case. A heat sink is installed in the upper part of the housing. It is a metal case. Upon completion of this process, the central processor looks like a finished product intended for consumption.
Note: metal heat sink is a key component of modern high-speed semiconductor devices. Previously, heat sinks were ceramic and did not use forced cooling. It was required for some models 8086 and 80286 and for models starting from 80386. Previous generations of processors had much fewer transistors.
For example, the 8086 processor had 29 thousand transistors, while modern central processors have hundreds of millions of transistors. Such a small number of transistors by today's standards did not produce enough heat to require active cooling. In order to separate these processors from those who need this type of cooling, the stigma “Heat sink required” was subsequently put on ceramic chips.
Modern processors generate enough heat to melt in seconds. Only the presence of a heat sink connected to a large radiator and fan allows them to function for a long time.
Sorting processors by characteristics
By this stage of production, the processor looks like it is bought in a store. However, another step is required to complete its production process. It is called sorting.
At this stage, the actual characteristics of the individual central processor are measured. Parameters such as voltage, frequency, performance, heat dissipation and other characteristics are measured.
The best chips are put off as products of a higher class. They are sold not only as the fastest components, but also as low and ultra low voltage models.
Chips that are not included in the group of the best processors are often sold as processors with lower clock speeds. In addition, lower-end quad-core processors can be sold as dual- or tri-core.
Processor performance
The sorting process determines the final values of speed, voltage, and thermal characteristics. For example, on a standard substrate, only 5% of the chips produced can operate at a frequency of more than 3.2 GHz. At the same time, 50% of the chips can operate at a frequency of 2.8 GHz.
Processor manufacturers are constantly finding out the reasons why the bulk of the processors are operating at 2.8 GHz instead of the required 3.2 GHz. Sometimes, changes may be made to the processor design to increase performance.
Production profitability
The profitability of the business for the production of processors and most semiconductor elements lies in the range of 33-50%. This means that at least 1/3 to 1/2 of the plates on each substrate are working, and the company is profitable in this case.
Intel’s operating profit margin of 45% for a 300 mm substrate is 95%. This means that if it is possible to make 500 silicon wafers from one substrate, 475 of them will be working and only 25 will be thrown out. The more plates you can get from one substrate, the more profit the company will have.
Intel Technologies Used Today
The history of the application of new Intel technologies for mass production of processors:
- 1999 - 180 nm;
- 2001 - 130 nm;
- 2003 - 90 nm;
- 2005 - 65 nm;
- 2007 - 45 nm;
- 2009 - 32 nm;
- 2011 - 22 nm;
- 2014 - 14 nm;
- 2019 - 10 nm (planned).
In early 2018, Intel announced the postponement of mass production of 10nm processors for 2019. The reason for this is the high cost of production. At the moment, the company continues to supply 10-nm processors in small volumes.
We characterize the technology of manufacturing Intel processors in terms of cost. The company explains the high cost of the technological process by the long production cycle and the use of a large number of masks. The basis of 10-nm technology is deep ultraviolet lithography (DUV) using lasers operating at a wavelength of 193 nm.
For the 7-nm process, extreme ultraviolet lithography (EUV) will be used using lasers operating at a wavelength of 13.5 nm. Thanks to this wavelength, the use of multipatterns widely used for the 10-nm process can be avoided.
The company's engineers believe that at the moment you need to polish the DUV technology, and not jump directly to the 7-nm process. Thus, processors using 10-nm technology will be discontinued for now.
AMD Microprocessor Prospects
Intel's only real competitor in the processor manufacturing market today is AMD. Due to Intel errors related to 10nm technology, AMD has slightly improved its market position. At Intel, mass production using a 10 nm process technology was very late. AMD, as you know, uses a third party to manufacture its chips. And now there is a situation where AMD uses the production technology of processors that are not inferior to the main competitor in the entire 7-nm process.
The main third-party manufacturers of semiconductor devices using new technologies for complex logic are the Taiwan Semiconductor Manufacturing Company (TSMC), the US company GlobalFoundaries and the Korean Samsung Foundry.
AMD plans to use TSMC exclusively for the production of next-generation microprocessors. In this case, new processor manufacturing technologies will be applied. The company has already released a number of products using the 7nm process, including a 7nm GPU. The first is planned to be released in 2019. After 2 years, it is planned to begin mass production of 5-nm microcircuits.
GlobalFoundaries has abandoned the development of the 7 nm process in order to focus on developing its 14/12 nm processes for customers focused on fast-growing markets. AMD is investing in GlobalFoundaries for the current generation of AMD Ryzen, EPYC, and Radeon processors.
Microprocessor production in Russia
The main microelectronic industries are located in the cities of Zelenograd (Mikron, Angstrem) and Moscow (Crocus). There is also own microelectronic production in Belarus - the Integral company, which uses the 0.35 micron technological process.
The processors are manufactured in Russia by the MTsST and Baikal Electronics companies. The latest development of the MCST is the Elbrus-8C processor. This is an 8-core microprocessor with a clock frequency of 1.1-1.3 GHz. The performance of the Russian processor is 250 gigaflops (floating point operations per second). Representatives of the company said that in a number of respects the processor can compete even with the industry leader - Intel.
The production of Elbrus processors will continue with the 1.5 GHz Elbrus-16 model (the digital index in the name indicates the number of cores). Mass production of these microprocessors will be carried out in Taiwan. This should help reduce prices. As you know, the price of the company's products is sky-high. At the same time, in terms of characteristics, components are significantly inferior to leading companies in this sector of the economy. So far, such processors will be used only in government organizations and for defense purposes. As a technology for the production of processors of this line, a 28-nm process will be used.
Baikal Electronics manufactures processors designed for industrial use. In particular, this applies to the Baikal T1 model. Its scope is routers, CNC systems and office equipment. The company does not stop there and is already developing a processor for personal computers - Baikal M. There is still little information about its characteristics. It is known that he will have an 8-core processor with support for up to 8 graphic cores. The advantage of this microprocessor will be its energy efficiency.