In the process of manufacturing microcircuits, some of the silicon wafers – round substrates up to 300 mm in diameter – inevitably turn out to be defective. Such plates can be reused, but until now China did not have the capacity to clean and recover used substrates. Since June of this year, China has launched its own production for the restoration of plates, which made the country less dependent on foreign partners.
Hefei Ultron Semiconductor Co’s 300 mm (12 in) silicon recovery plant began construction in March 2020. In December 2020, the plant was commissioned, and pilot production was launched in March. In June 2021, the company began fulfilling mass orders, the main one among which, according to local sources, was an application for the recovery of platinum for the production of 14nm semiconductors.
From this message, in particular, it follows that the level of defects in the production of 14-nm chips by SMIC is very, very high. This again confirms reports that China is not ready for truly mass production of 14nm solutions.
As for the production of Hefei Ultron Semiconductor, when it reaches full capacity, the company will be able to recover up to 1.68 million 300 mm wafers annually. This is a significant savings in the production of new chips and even in the case of plate refurbishment. Before that, orders had to be placed in Japan or other countries.
It should be noted that the work on the restoration of defective plates is a complex work that requires high-tech equipment and a “clean” room. The top layer of crystals with impurities must be removed with high precision and then the surface of the substrates must be re-polished. This is also part of an important infrastructure for creating a national chip production independent of imports in China or in any other country.