Traveling through the sword to engage in military industry.

The automotive industry was about to take off. The next thing could not be rushed, it would take time to ferment slowly, plus the further polishing of the entire product, so Ren Zhong no longer cared about these details.

Ren Zhong turned his attention to the development of communications.

For Dongda, the old-fashioned large-scale vertical and horizontal automatic telephone exchanges have long been broken through. Relying on this old-fashioned exchange produced by itself, the first urban network has been established in the country. However, due to the inherent technical weaknesses and patent restrictions of this vertical and horizontal exchange, this exchange is destined to never go abroad.

Therefore, Ren Zhong did not develop this technology much in his plan. He only stopped the research and development of this old-fashioned switch after building a simple telephone network for government agencies and factories at the prefecture level.

According to the task assigned by Ren Zhong to the Communications Research Center, the main task is to develop the next generation of programmable switching systems for the world and to take a new technical route.

This technical route is also a proven direction of communication technology development in the main world.

Although it is still a bit difficult to develop program-controlled switches now, under the impetus of Ren Zhong, Dongda's accumulation of basic IT technologies has actually surpassed the level of the main world in the 60s. With the technological advantages in transistors and integrated circuits, it has all the basic capabilities to develop program-controlled switches based on the current technology.

As for the future development of communication technology, Ren Zhong did not skip the plan of the development of the times. He did not understand these things, so he completely copied the steps of the development of the communication industry in the main world.

The first wave is to recreate the Bell No.1 ESS system in the world of Bright Sword.

This is the first commercial programmable switching system in the history of the main world.

Some technical information about this system had been decrypted long ago. Ren Zhong spent some money to get the detailed circuit diagrams and main program control programs, and then brought these things into the world of Bright Sword.

Although the technical accumulation of the communication research center team in the world of Liangjian is inferior to that of the engineers in Bell Labs in the main world.

However, what Ren Zhong brought into the world of Bright Sword was not only the design of this system, he also brought some basic knowledge such as the communication principles of the main world, textbooks on the general description of the principles, etc., so that the engineers engaged in research and development in the Communication Research Center could have the opportunity to learn on their own.

We will not go wrong if we continue along the path of the development of the main world's communications industry. However, considering that the accumulation of the entire industry's development is not just about copying designs, more importantly, there are opportunities for theoretical learning and improvement at the principle level. We need to ensure that we build a team of qualified talents who truly understand the principles and core technical points, and who can also automatically develop derivative products in the future. Therefore, there is a lot to be done now.

Start learning from the principles, then carefully study and transform the design materials provided by Ren Zhong, and fully understand all the principles and technical points built into the technical materials!
Precisely because there are so many things to be solved, progress is relatively slow. In fact, the Communications Research Center solved the design and production process of vertical and horizontal switches in the last five-year plan, and has accumulated a lot of basic knowledge about telephone switches.

After they turned to the research and development of programmable switches, they absorbed a lot of basic electronic component knowledge from the design and production of vertical and horizontal switches. Now they want to replace these functions with integrated circuits. For the Electronic Research Center, which has already overcome many difficulties in the design and production of integrated circuits, such new research and development needs will naturally not be a big problem.

The three closely related research institutes, namely the Electronic Research Center, Communications Research Center, and Computer Research Center, which are now gradually becoming specialized and divided, have their own independent research topics. At the same time, they are also constantly integrating and jointly promoting the most core research in the future IT industry.

With Ren Zhong's support, Dongda took a step ahead in the development of transistor technology and created the first transistor computer in the world of Sword and Fairy. It also moved faster and faster on the road of transistor development, making the development of transistor technology at least five years ahead of the world of Sword and Fairy.

But this is just the first step for Todai to take the lead in IT technology.

Next, in terms of integrated circuits, Dongda was also the first to break through and complete the integrated circuit design and production process, further expanding its leading edge in the IT industry and achieving mass production and large-scale application of integrated circuits several years ahead of many of its competitors in the world.

And we have applied for many patents for many proprietary integrated circuits.

The functions of early integrated circuits were relatively simple, and the production process was relatively simple. Usually, a whole set of planar process technologies such as grinding, polishing, oxidation, diffusion, photolithography, epitaxial growth, and evaporation were used to simultaneously manufacture transistors, diodes, resistors, capacitors and other components on a small silicon single crystal wafer, and certain isolation technologies were used to isolate the components from each other in terms of electrical properties. Then, an aluminum layer was evaporated on the surface of the silicon wafer and etched into an interconnection pattern using photolithography technology, so that the components were interconnected into a complete circuit as needed to make a semiconductor monolithic integrated circuit.

It took the University of Tokyo nearly five years to complete the development of this process. In 5, it began to develop CMOS circuits composed of NMOS and PMOS symmetrical complementary devices, and developed the CMOS technology process that is familiar to the world.

But when technology developed to this stage, Ren Zhong introduced more advanced next-generation integrated circuit production technology to the world of Bright Sword, and introduced the milestone 8080 chip!

By the 8080 stage, these new integrated circuits were very similar to the computer chips that Ren Zhong was familiar with.

In order to reduce the time of the entire technology iteration, Ren Zhong also found relevant professional and technical personnel in the main world to sort out the complete set of 8080 production processes and equipment.

The production of 8080 chips involves multiple key steps and equipment, including wafer manufacturing, mask production, semiconductor manufacturing, packaging and testing, etc. The information was clearly made available, and the chips were shipped to the world of Liangjian for secondary realization, including the re-development of these equipment.

This was not an easy task. Even though we had previously researched large-scale integrated circuit production equipment, it was still very difficult to research the equipment needed for 8080 production.

The first to be affected is high-purity wafer manufacturing.

This process includes crystal pulling, wafer slicing, wafer grinding, etching, silicon wafer polishing, cleaning and wafer epitaxy processing, involving high-purity materials and strict temperature control to ensure the quality and purity of the wafer. Mask making is to use photolithography technology to expose photosensitive materials with ultraviolet light, and then form the required circuit pattern on the chip surface by chemical corrosion or deposition. This step is the key to ensuring the accuracy and reliability of chip design. In the chip manufacturing process, this stage is the most core so-called photolithography link.

This manufacturing process involves multiple process steps such as deposition, corrosion, and cleaning, which are technically difficult. In particular, ion implantation is a key step in changing the conductive properties of silicon wafers and forming electronic components such as transistors. This process requires precise control of the concentration and temperature of various chemicals to ensure the performance and stability of the chip.

The process design and implementation involved are the most difficult steps in the chip manufacturing process, no doubt about it.

However, the early production equipment was not so perfect, so the chip production in the main world in the 60s relied more on manual work!
The hand-rubbed chips were no joke. The first generation of chip engineers first drew the integrated circuit layout on graph paper with colored pencils, then used a fine blade to connect the transistors and circuits on the rubylith mask by hand, carving them out bit by bit. Finally, they used a camera to shrink the template pattern 50-100 times to obtain a photomask for photolithography. The original lithography machine that matched this manual mask was the contact lithography machine, so the first generation of lithography machines was just an auxiliary tool for manual hand-rubbed chips.

It depends more on the technical level of the engineers.

This type of contact lithography machine simply and roughly covers the photomask on the silicon wafer, and the mask is in direct contact with the photoresist coating, and then it is illuminated to complete the exposure. However, the failure rate and cost of this lighting method are very high, because the colloid itself and the floating dust particles attached to it will not only affect the lithography effect, but also cause pollution and damage to the photomask, and the damage effect will accumulate with the number of lithography times. This not only makes the yield of each lithography low, often only 10 out of 1 chips can be engraved, but also seriously consumes the life of the photomask, resulting in a mask that can only be used a dozen times at most. As a result, the cost of manufacturing chips is very high.

This is how early chips came about with low quality and high prices.

However, this method initially solved the problem of whether or not there is technology. Only with this technology can more powerful chips be produced.

In theory, it is not difficult to solve this problem. Intuitively, just lift the photomask a little bit to prevent it from contacting the photoresist.

Early engineers thought the same. So they added a movable platform in the horizontal and vertical directions, as well as a microscope to measure the distance and overlay between the photomask and the silicon wafer, to the contact lithography machine, so that the two could be as close as possible during lithography, but not in direct contact. This is the progressive lithography machine. It avoids the photoresist from contaminating the photomask, but it brings a new problem: the accuracy of the lithography machine decreases due to the diffraction effect of light.

On a macro level, we believe that light propagates in a straight line, but on a micro level this is not the case. Light has wave properties, and when it passes through a small hole or encounters a tiny obstacle, it will produce diffraction, or deviate from the original straight-line propagation and shine on places it should not. The larger the wavelength of the light source compared to the narrow slit, the more serious the diffraction phenomenon. It's like you hold a knife and want to cut a 100-nanometer-wide cut in a silicon wafer, but you find that the blade is only 400 nanometers wide and can only be used to cut melons.

In progressive lithography, the accuracy of lithography is not only limited by the wavelength, but also depends on the distance between the photomask and the silicon wafer. The larger the distance, the greater the error between the projection on the silicon wafer and the pattern on the mask. If the photomask is raised, the lithography accuracy is not enough; if the photomask is lowered, the lithography cost is too high. This period of hesitation between contact and progressive lithography machines is the era of shielded lithography in the history of semiconductors. These two ancient lithography machines are collectively called Mask Aligner. The 1:1 photomask they use is a light shield. The lithography machine only needs to shine light and shadow on the silicon wafer. It has a simple structure and does not require any complex optical system.

Contact lithography machine
Although this contact lithography machine can also be used to produce chips, early SRAM memory chips and the first commercial CPU in ancient times were all produced using this equipment, but few people could afford it at the time. The reason was that the production yield of contact lithography was too low and the loss of photomasks was too great, resulting in the chip price being too expensive. It could only be used in scenarios such as scientific research and military industry where cost was not a consideration.

Obviously, if photolithography technology is just like this, then the popularization of chips will be just empty talk, so scientists in the IT industry have not stopped.

They hope to make a lithography machine with high precision that does not require pressing the photomask onto the photoresist.

This is the real starting point of modern photolithography technology. At this point, the photolithography machine officially moved from the contact type to the projection type, realizing the structure of the modern photolithography machine No. 01.

The new changes are not complicated. The new generation of photolithography machine Micralign in the main world adopts a reflective projection method. It uses two coaxial spherical mirrors to project the pattern on the photomask onto the silicon wafer after three reflections. This symmetrical optical path design can eliminate most of the aberrations produced by the spherical mirror, allowing the photolithography pattern to achieve the ideal resolution.

In this way, through the birth of the latest model of projection lithography machine Micralign, the yield rate of chip production increased from about 10% of contact lithography to 7% overnight. This leap in lithography technology led to a sharp drop in chip prices. In the history of the main world, Motorola once had a microprocessor called 70, which was produced using a contact lithography machine. The unit price of each chip was 6800 US dollars.

The following year, eight engineers left Motorola and joined MOS Technology. They took the design circuit diagram of 8 and simply modified it, and directly used the newly born projection lithography machine to produce a MOS6800 that was highly similar to 6800. The chip with the same architecture not only had stronger performance, but also dropped a lot in price, selling at a bargain price of only 6502 US dollars!

The price was reduced by more than 90% in one go, it’s really a steal!

The power of technological progress is evident.

Ren Zhong asked the R&D engineers at the Electronic Technology Research Center to go through this process from beginning to end. Unlike the main world, there is a feasible path for all of this, so the time it takes for the entire process to mature was greatly reduced, allowing the first generation of lithography machines to be produced more quickly.

As for packaging and testing, this is the last step in chip manufacturing and is considered to be the step with lower technical difficulty. It mainly involves connecting the chip to external pins and encapsulating it in a protective casing so that it can be connected and installed with other electronic devices.

Since chip testing is relatively complex, it has become an independent stage. This stage mainly conducts comprehensive testing of the chip's functions, performance, and reliability to ensure that it meets design requirements.

In the early days, it was intertwined with chip production, but later it became an independent step, thus making the professional division of labor in chip manufacturing more detailed and more efficient.

However, in the early stage of chip development in Liangjian World, it naturally cannot be separated. Instead, after researching and improving the packaging and testing process equipment, special packaging workshops and testing workshops were set up to perform the final link of chip manufacturing.

After several years of development, the process design and equipment for these steps were finally complete.

The first real CPU produced was the 8080 that Ren Zhong borrowed from the main world! (End of this chapter)