NAND makers reportedly struggle to improve QLC yields

QLC NAND promises to deliver memory with increased levels of storage capacity per cell, offering a 33% increase in storage potential over today’s TLC memory. Today, Samsung, Intel, Micron, Toshiba and Western Digital are all capable of manufacturing QLC memory, but sources from Digitimes have claimed that manufacturing yields are lower than expected, preventing the memory type from reaching the price points and manufacturing levels that are required to have a significant impact on the DRAM market. 

DigiTimes has reported that manufacturers are struggling to get their manufacturing yields to over 50%, which means that around half of the QLC NAND chips that are produced are non-functional or otherwise faulty. Increasing silicon yields is one of the ways that manufacturers can improve profitability, increasing their effective production rate (as more chip work), which increases their return on investment (getting more working chips from a single wafer means more profit).

Lower than expected manufacturing yields has led to an undersupply of QLC NAND, which has prevented most manufacturers from releasing QLC-powered SSDs. Beyond that, low manufacturing yields also make it possible that TLC NAND is more profitable to produce, giving QLC NAND no competitive value. 

If DigiTimes’ information is correct, it means that it will take a while before QLC NAND becomes a commonplace within the storage market, as yields will no doubt improve over time.