What does nanometer means in processors? Photolithography?

Hello friends and welcome back to your own tech guide: Techanalysia. With smartphones launching every month on regular basis with new features added to them, then there is one term you've crossed paths whenever you see a launching of a smartphone or an ad on a webpage, on YouTube, and any social media platform you use. That term is "nm" which stands for "nanometer". You may have seen this:

• The X smartphone launches with this latest X processor based on the 7nm/10nm/12nm/14nm process.

Photolithography process definition

In the past few years, this "nm" term has been around quite a bit, yet there is a lot of confusion among most of the users. So today here we try to minimize that bit of confusing part in the smartphone industry. So without further delay, let's get started.

As I told you previously in my articles, smartphone CPUs are designed using millions of tiny transistors, which are combined to make electrical switches that switch on and off to perform calculations. This clearly requires power to function all this. So if you make a transistor small it will consume less amount of power. All this is because the capability to store electric charge decreases.

Last year, in 2019, Apple launched its X series of  Smartphones (iPhone XS, iPhone XS max) with A12 Bionic mobile processors. This series was the first smartphone series to be featured with a "7nm" fabrication process chip. After this, chipset giants Qualcomm and Huawei also released their "7nm" mobile SoCs namely Snapdragon 855, 855+, and Kirin 980 respectively. 

CPUs are being manufactures using this process called the 'Photolithography process', where an image of a CPU is etched onto a piece of silicon. The method of how all this is done is called the 'Process Node'. The calculation of being how small these transistors can be made is measured in "nm". The first-ever transistor was made notably measured in 10µm, which means a micrometer in 1971. It was a small size though, but it can't stand against the transistors we are using today with current-generation technology.

Small transistors are more power-efficient, they can do more & more calculations without causing any heat issues, which is in fact a limiting factor for CPU performance. It also allows manufacturers to shrink the die size, with further reduces overall cost and increases the density on the same size,(this means more transistors in the same small size). 

So by shrinking the size of transistors, we can imbed more transistors in the chip area. when we shrink a transistor it changes completely two important aspects of SoCs. Performance & Efficiency.

• With the decreased size of the transistor, we can put a lot of them in the same unit area. This way we can achieve better processing power from the same sized processor. 
• These small transistors require very minimal power to function which reduces the overall power consumption of SoC. Less requirement of power results in less heat generation thus allowing manufacturers to increase clock speed further. 

So, What are these terms "7nm, 10nm, 12nm, 14nm...." actually?

These, 7nm, 10nm, 12nm, 14nm, 20nm, values actually represent the fabrication technology used to manufacture them, instead of the size of the transistor. In the past, the gate pitch of a transistor was extracted the same as fabrication technology (nm value), but in today's era, this is demolished. In today's era, it's just become a marketing gimmick for companies who manufacture them. There is no definite standard to calculate these values. Different companies have different methods to calculate this. For example, 

• The 10nm from TSMC (Taiwan Semiconductor  Manufacturing Company) is not equal to that of Samsung's 10nm.
• Intel's 10nm is similar to TSMC's 7nm. 
• And believe it or not, Intel's 10nm ＞ 7nm of Samsung and TSMC.

So, nowadays these all 7nm, 10nm, 12nm, 14nm,...are no more in the game anymore, nowadays, how many transistors a manufacturer can put on a small size say, a millimeter square area (mm²).

So, what matters now? 

Transistor Density

• Transistor density means the total number of transistors per mm square area.
• Measured in (MTr/mm²) which stands for millions of transistors per square millimeter.
• The fabrication process with higher transistor density is what matters now the most. 

For Example: 

• In Apple's 7nm process the transistor count is 96.49 MTr/mm².
• In Intel's 10nm process this count goes up to 100.8 MTr/mm².
• In AMD's Ryzen 3000 7nm process this goes up to 95 MTr/mm².
• In TSMC's 7nm process the transistor count is 96.5 MTr/mm².
• In TSMC's 10nm process the count is 60.3 MTr/mm².

So, I hope this might clear some things about "nanometer" and "transistor density" in smartphone SoCs.

The biggest impact of reducing the size of transistors will be on the smartphone industry. Some major manufacturers already launched the "7nm" fabrication technology for making smartphone SoCs. Some reports claimed that two major Semiconductor manufacturers "TSMC" & "Samsung" are already locking horns in the race of next-generation "5nm" SoCs. 

Reports also claimed that Samsung might have lost Qualcomm's 5nm chip orders to TSMC. And TSMC will start making off 5nm iPhones & Qualcomm's 5nm SoCs in Q2 2020.

Conclusion

So that's it for today folks, I hope you learned something new today like, what is a nanometer? And what photolithography process is? 

If you liked what you learned today then tell me in the comment section down below and share it with your friends.