ST tips Hua Hong deal to support ‘China-for-China’ strategy

European chip giant STMicroelectronics NV has revealed it is transferring its 40nm embedded non-volatile memory (eNVM) CMOS logic process to foundry Hua Hong Semiconductor Ltd. (Shanghai, China) as part of its ‘China-for-China’ strategy.

Hua Hong, sometimes known as HH Grace, is China’s second largest foundry after Semiconductor Manufacturing International Corp. (SMIC). The manufacturing process technology transfer will see 40nm STM32 microcontrollers being manufactured at Hua Hong’s Wuxi 300mm-diameter wafer fab under a foundry service by late 2025, ST said.

The move is intended to allow seamless second-sourcing of ST’s microcontrollers and improved sales into China said Reme El-Ouazzane, president of the microcontrollers business group at ST, during the company’s ‘Capital Markets Day’ held in Paris, last week.

“We have been, we are and will continue to see a decoupling of the supply chain in years to come. And this is why close to 18-months ago we took the strategic decision to enable our eNVM 40nm generation to be manufactured in China end-to-end,” said El-Ouazzane.

“We are using the exact same mask set to produce the wafers in Crolles or – moving forward – in China at HH Grace, the partner we have selected for this initiative,” he added.

At the Capital Markets day detailed presentations were made to financial analysts. It come shortly after ST had published disappointing financial results including a drop of 43.3 percent in microcontroller sales year-on-year.

ST’s senior management was asked during a Q&A session of the meeting how ST intellectual property would be protected during and after such a transfer.

El-Ouazzane said that the technology was being carefully deployed with much use of encrypted data files. He added that Hua Hong already has an embedded flash non-volatile memory process on 40nm CMOS. “We are not accelerating something they are already having. But using our process [for ST products] is much more efficient for many reasons.”

El-Ouazzane stressed during his presentation: “We are not talking about designing our product twice; against our own PDK [physical design kit] and then against the Chinese foundry’s PDK. That would be woefully inefficient.”

Fabio Gualandris, in charge of quality, manufacturing and technology at ST, added that testing of ICs coming off the production line is an essential part of production and that ST’s test routines are developed elsewhere and would be brought to China and deployed at a separate location away from the fab in China that is under ST’s control.

Not PCM but similar to SiC

ST has embedded phase change memory as a digital logic option on 28nm CMOS and 18nm fully-depleted silicon-on-insulator and is one of very few companies to offer this but, at least for now, this is not part of the technology transfer.

ST already has a share in a joint venture 200mm wafer fab in Chongqing with Sanan Optoelectronics for silicon carbide (SiC) devices.

That fab was intended to use Sanan supplied wafers and ST’s process technology exclusively to produce power devices for ST in support of Chinese demand for car electrification and industrial power and energy applications.