Samsung Reportedly Improves Yield of DRAM for HBM3E and HBM4

According to reports that South Korean media outlet citing internal sources, Samsung Electronics' DS division has recently increased the yield of its 10nm-class fifth-generation (1b) DRAM, used in the core chips of HBM3E, to 92% (based on cold test). In addition, the yield of sixth-generation (1c) DRAM, to be installed in HBM4, has been raised to over 75%.

Samsung initially struggled to further improve the yield of its 1c DRAM after reaching around 60%. However, it appears to have achieved rapid yield improvement in a short period by deploying a dedicated technical team of 400–500 people on the actual mass production line while simultaneously “ramping up” production volume, thereby realizing on-site improvements.

The 1b DRAM chip, which has now reached a 92% yield, is assessed as having a "mature" yield, with defect rates controlled near zero. This means Samsung has secured an overwhelming cost advantage over competitors and possesses a well-established manufacturing capability to supply defect-free products in large volumes to major global tech customers in a timely manner.

According to sources, the top priority for the 1c DRAM process is to raise its yield to the level of the 1b DRAM (92%) as quickly as possible.

However, if the general strike planned by the union for the 21st comes true and production personnel leave their jobs shortly after having improved the yields of 1c and 1b DRAM, the process stability would collapse. In that case, significant time and money would be required to return to the target yield levels, and the hard-won gains in yield improvement could be all in vain.