ChangXin Memory Technologies (CXMT), a leading memory maker from China, has begun to mass produce HBM2 memory, reports DigiTimes. If the report is accurate, then CXMT has begun mass production of memory crucial for AI and HPC processors about two years ahead of the expected timeframe.
Earlier this year we reported that CXMT began to acquire tools necessary to make high-bandwidth memory (HBM) products and typically it takes at least a year, more likely two, to start mass production with decent yields. CXMT has ordered equipment from suppliers in the U.S. and Japan, with U.S. companies like Applied Materials and Lam Research receiving export licenses to supply fab tools. Producing HBM involves a complex process, including the building and testing of memory devices (which are larger than the commodity DRAMs that CXMT typically produces), base dies, and then final assembly.
Apparently, China’s desire for self-sufficiency in memory technology is so high that CXMT began to produce HBM2 memory well ahead of schedule, albeit with unknown yields.
HBM stands out as the top performer in terms of bandwidth due to its 1024-bit wide interface and relatively high data transfer rates, which we are talking about ranging from approximately 2 GT/s to 3.2 GT/s per pin in the case of HBM2. It’s wide interface and vertical stacking design mean that producing HBM devices does not necessitate the latest lithography technology, but requires sufficient manufacturing capacity as HBM DRAM ICs are physically larger than typical commodity DRAMs that CXMT makes. In fact, leading global DRAM manufacturers often use established technologies for their HBM2E and HBM3 products, so we would expect something similar from CXMT.
However, HBM production requires advanced packaging techniques. Connecting eight or twelve memory devices vertically using small through silicon vias (TSVs) is a complex process. Still, despite this complexity, assembling an HBM-like known-good stacked die (KGSD) module is actually less challenging than manufacturing a DRAM device using 10nm-class process technology.
With HBM2 production today, CXMT still lags behind global competitors like Micron, Samsung, and SK hynix in DRAM technology, as these companies are already mass-producing HBM3 as well as HBM3E memory and are gearing up to mass-produce HBM4 with 2048-bit interfaces in the next couple of years.
But for China in general, HBM2 is a crucial technology for its advanced AI and HPC processors. Huawei’s Ascend 910-series processors use HBM2 memory and producing such memory domestically is a big deal for the Chinese tech industry.
