At that time, this brother also rubbed out a handicraft, which could not talk about practicality at all, and even "could not light up".
In fact, it is normal to not light up, and making chips is a nano-level carving art, which can be said to be the peak of human technological advancement.
Every step in the manufacture of a chip requires extremes, such as silicon wafer purification. It's like you have to write millions of words in your hair, and you can't write a single word wrong.
Another example is the reflective mirror in the lithography machine, which, in asML parlance, is the smoothest man-made structure in the universe.
How flat is it? If this mirror is the size of the earth, then its uneven place is the thickness of a hair.
Coupled with those laboratories that are often billions, even in such a harsh environment, there will still be a low yield rate and the probability of bad films.
BUT....
A 22-year-old guy has hand-rubbed a chip in his garage, and it can be used. I suspect this dude has an Iron Man-like "Jarvis" in his house.
But then again, the chip is such a sophisticated thing, why can someone always rub it out at home?
In fact, the chip manufacturing principle is not complicated, and the difficulty is to make a chip that is small enough, can be scaled and has a very high yield.
The working principle of the "circuit" in the chip, we learned it in the nature class when we were young, using one end of the wire to connect the battery, the other end to connect the bulb, and then connect a switch in the middle of the wire, and the switch will turn on as soon as the light is closed.
It's just that we have to shrink the above set of things connected by wires to the nanometer level.
After continuous experimentation, scientists have discovered semiconductor silicon, which can precisely control the resistivity of silicon wafers by adding appropriate dopants, to put it bluntly, it can be used as a "wire" for traditional circuits.
The insulating and light-sensitive photoresist becomes the "switch" of the traditional circuit. With guys who can conduct electricity and power off, there are traditional circuits.
Such a wire switch can be spread across the entire silicon wafer to form a chip.
So after talking about the principle, let's talk about manufacturing. This process is roughly divided into raw materials, photoresist, lithography, doping and testing.
The blogger of the hand rubbing chip this time obviously does not have the ability to purify the industrial-grade finished silicon wafer, so the first step is to spend $45 to buy a piece of finished silicon wafer, and the merchant has done a good job of cutting and external treatment, and go home and directly break it into a half-inch square shape.
The above steps, as long as you have nail clippers at home you can also do.
The wafer is done, and the next step is to apply the photosensitive material photoresist.
Place the wafers in a homemade centrifugal coater and light a drop of 100 μl of photoresist. Turn it at 4000 rpm for 30 seconds so that the photoresist is evenly applied to the wafer.
Pinch the wafer and place it on a hot plate at 96 degrees Celsius, dry it for a minute, leaving a layer of solid film evenly covered on the wafer.
In the above step, as long as you have a washing machine at home, you remove the motor and insert the wok on the motor, and you can do it on the wafer sticker.
Then there is lithography, and the role of lithography is to print the circuit on the wafer.
Pay attention to this keyword, India!
Before printing, you have to have a template, take out the circuit diagram designed in advance, put it under ultraviolet light, and the circuit diagram is printed as soon as the lamp shines.
Because the photoresist is sensitive to ultraviolet rays, the photoresist dissolves where the ultraviolet rays have been irradiated, and the prototype of the circuit is formed.
In the above step, as long as you can use Photoshop, you can also draw a circuit diagram at home.
But the next steps are basically unlikely to be completed at home, because the next step involves lithography.
As we all know, the most important thing about the lithography machine is light.
In order to build chips from 14nm to 7nm to 5nm or even 3nm, we need shorter and shorter ultraviolet wavelengths.
This requires that at the nanoscale, the light pulse of the DUV is used to strike the liquid metal tin twice in a row, and the EUV with a shorter wavelength can be excited, and then the EUV can be carved out of a chip with a smaller process, which is the following GIF.
It's right not to understand it, because there is no second company in the world that can do it except the Asma in the Netherlands.
However, this brother bought a projector on Amazon, and then got a microscope and a projector to assemble, and made a simple "lithography machine".
After using this "lithography machine" to complete the "projection lithography", the brother puts the chip into the chemical reagent, which can deepen the original gully, make it engraved on the wafer, and finally rinse off all the photoresist.
This also completes the initial etching.
But at this point, the chip still has no soul because it "does not conduct electricity".
The next step is to give the silicon transistor electrical properties through ion implantation, which is to make it conduct electricity and become a wire.
At this time, you have to use another thing that is more complicated than the lithography machine, the etching machine.
How hard it is to build this thing, take an example of etcher dust control.
In the case of a common chip made of 5nm, for example, there can be no more than two particles larger than 20nm in diameter on a 12-inch wafer.
This is equivalent to 722,300 square kilometers of land in Qinghai Province, allowing only 2 grapes of dust.
The etching machine can inject boron or phosphorus into the silicon structure, and then embed a little copper to make a "battery cell" in the wire, so that the "battery cell" can be connected to other transistors.
After that, a layer of "tempered film" must be attached with vapor deposition technology to protect the finished circuit from corrosion and become more robust.
The etching machine of Zheng'er Bajing requires the use of professional ion implantation machines and vapor deposition technology. This method is quite expensive and even a little dangerous, and the explosive gas silane is used in the process.
Let's not say that the danger is not dangerous, the etching machine you can't get ah... So, this dude moved an "oven".
Here, he employs a particularly ancient method of high-temperature diffusion, also known as annealing.
Place the etched and rinsed wafers in a professional "oven" at 1000 degrees Celsius and bake for 45 minutes so that the phosphorus atoms can be embedded in them.
Finally, put in the vacuum machine from the second-hand market, "paste a film" to the chip, and the first layer of the circuit is completed.
After that, a layer of photoresist is applied to the wafer, and then the above steps such as lithography, etching, doping, etc. are repeated to make the second layer circuit, the third layer circuit...
This basically gets the chip done.
When the chip comes out, you have to detect a wave first to see if there is anything bad.
This requires the use of electron microscopes. This thing can detect fine structures smaller than 0.2um, which is 1/100th the size of a human hair.
As for the price... Chip manufacturing grade electron microscopy is about a few million, and the working environment is quite elaborate, dust-free and the temperature is suitable, even if you can get one, the garage is unlikely to meet the requirements.
As a result, the dude spent $1,000 directly on a $250,000 electron microscope that cost $250,000 in the 90s, and fixed it.
This brother uses this machine to check for defects in the chip. He broke the chip, used an electric mirror to observe the cross-section of the chip, if there are dust particles doped into it, the chip is scrapped, this step can also be tested by the way how his dust-free is done.
After inspecting the package correctly and cleaning the package thoroughly, he pulled out a silicon chip with a perfect color, a length and width of 2.4 mm, and a total of 1200 transistors.
Finally, a simple "light up" test is performed.
Putting the chip into a 20-year-old analyzer, the chip showed a perfect voltage and current curve, and the manufacturing process of the hand-rubbing chip was declared a success.
Although there are now tens of thousands of transistors in a roadside computer that can add, subtract, multiply and divide, you should not underestimate this hand-rubbing chip.
It has 1200 transistors, has approached the number of 2200 transistors of Intel's first generation chip 4004, regardless of the repetition rate and yield rate, this hand rubbing chip has reached the level of the 60s and 70s of the last century, and the little brother also named it Z2.
That's right, there is also a hand-rubbing chip called Z1, when he was a high school student, he rubbed a 6-transistor chip in his garage and successfully used it on an LED light.
But the Z1 requires one or two 9V batteries to drive. This time, the number of Z2 transistors has grown exponentially, but only a 2.2 or 3.3V battery is needed to carry it.
After talking about the chip, let's look at the guy who made the chip and his "garage".
The little brother is Sam Chiluf, his father is a racing parts industrial designer, his brother is a robot engineer, and his garage is full of professional instruments.
This is obviously the laboratory with the "garage face".
Even before making chips, his father specially invited a 40-year-old senior engineer in the semiconductor industry to test the "garage" for the little brother to see if the position of the plug board was reasonable, whether it was easy to cause fires and so on.
The little brother relied on a pile of rags from the second-hand market to directly rub out a chip, which can be called the strongest garbage guy in history.
But it is undeniable that his family environment has helped him a little bit, so that he has enough confidence to do this, whether successful or not.
What's the point of spending $50,000 on a $1 chip?
To quote a blogger, "Others think it's an impossible thing, I think I can do it, I just do it, I don't think I'm going to succeed, and I think keep learning is the biggest challenge." ”
In the face of a new field, what we are gradually missing is not exactly what the little brother said, those who should have disobedience and self-confidence as young people.
Author: yx Editor: Surface Cover: Xuanxuan
bibliography:
YouTube – "Z2" - Upgraded Homemade Silicon Chips
Making Microchips at Home - Cooking with Jeri Part1
CCTV News - What is a chip IC?
Tiger Sniffing Net – A 22-year-old boy who builds a chip in an underground garage