Top Chinese memory chip maker YMTC makes another design breakthrough, defying US sanctions

Yangtze Memory Technologies Corporation (YMTC), China’s leading flash memory chip manufacturer, has achieved a significant technological breakthrough despite US sanctions, amid Beijing’s push for technological self-sufficiency, according to a report by TechInsights.

YMTC has implemented its new Xtacking4.0 memory chip design in its highest-density 3D NAND chip, which was discovered in the commercial ZhiTai TiPro9000 solid-state storage device, according to a recent report from Canadian integrated circuit (IC) research firm TechInsights.

The chip features a dual-deck structure – a lower deck with 150 gates and an upper deck with 144 gates – totalling 294 gates. It uses what is known as a hybrid-bonding technique to join two wafers together.

Following last year’s release of Xtacking4.0 devices such as YMTC’s 160-layer product, industry observers anticipated the company would incorporate this architecture into products with higher layer counts.

This new design surpasses the sophistication of its predecessor, which had a total of 180 gates. While featuring a modified internal layout, its most notable achievement is storage density, with an industry-first capacity of over 20 gigabits per square millimetre. TechInsights estimates the design contains around 270 active memory layers.

“The important takeaway is that China’s YMTC has beaten the competition to market,” said TechInsights senior analyst Jeongdong Choe, who wrote the report. “With the new Xtacking4.0 technology, YMTC appears to have found a way to overcome the current ban with this new chip.”