Why they do this can be only guessed, but it is a fact that SMIC has made chips using a 7 nm FinFET CMOS process very similar to the TSMC 7 nm process.
This has been discovered by studying with an electron microscope some samples of ASICs made at SMIC for crypto mining.
This story has been reported in a large number of publications and it is possible to buy a detailed report with the result of the investigations about the secret 7 nm process of SMIC.
Because of the similarities with the TSMC process, and because it is known that SMIC has hired former TSMC employees, it is believed that SMIC might have copied various parts of the TSMC process, which could be a reason to not bragg about it.
However such copying is not as simple as non-specialists may believe. I have worked in semiconductor manufacturing, and even if you have all the details about how a technological process is done in another plant, when using other equipment you will not be able to reproduce the results without a lot of tweaking and changes.
Having stolen information about how the competition does it is helpful and it can shorten a lot the development time, but it cannot replace the need for a team of competent engineers, able to develop such a process by themselves, even if in a longer time.
This has been discovered by studying with an electron microscope some samples of ASICs made at SMIC for crypto mining.
This story has been reported in a large number of publications and it is possible to buy a detailed report with the result of the investigations about the secret 7 nm process of SMIC.
Because of the similarities with the TSMC process, and because it is known that SMIC has hired former TSMC employees, it is believed that SMIC might have copied various parts of the TSMC process, which could be a reason to not bragg about it.
However such copying is not as simple as non-specialists may believe. I have worked in semiconductor manufacturing, and even if you have all the details about how a technological process is done in another plant, when using other equipment you will not be able to reproduce the results without a lot of tweaking and changes.
Having stolen information about how the competition does it is helpful and it can shorten a lot the development time, but it cannot replace the need for a team of competent engineers, able to develop such a process by themselves, even if in a longer time.