QLC NAND flash memory yields still an issue

Industry sources told DigiTimes that flash memory makers are still struggling to achieve yields of over 50 percent for QLC NAND flash memory. The site reports the market may get disrupted by a flood of substandard chips, similar to what happened with TLC. Yields of 3-bits-per-cell memory were unsatisfactory in 2018, and yields improved at a slower-than-expected pace:

NAND chip vendors had their 3D TLC NAND manufacturing yield rates improve at a slower-than-expected pace causing a build-up of substandard chip stocks earlier in 2018. The memory prices came under further downward pressure in the second quarter, as substandard chips began to flood the supply chain, the sources noted.

NAND chip vendors were unable to improve substantially their 3D TLC NAND yields until recently, the sources continued. Nevertheless, they are now struggling to improve their manufacturing yield rates for QLC NAND products, which were introduced earlier in 2018, to over 50%, the sources said.

The sources indicate the production of QLC NAND flash memory is a tougher-than-expected nut to crack.