Toshiba is trying to challeng rival Samsung Electronics by manufacturing the first 64-layer 3D NAND flash memory chips in the third quarter of this year. Samsung is also expected to release the same type of products a qyuarter later.

The world’s first 3D NAND memory chip was manufactured by Samsung in 2013. Storage cells are stacked vertically resulting in significantly improved memory capacity and speed compared to flash memories. A 64-layer 3D NAND flash memory chip, in particular, has an important significance in that it exceeds the productivity and performance of planar NAND flash memory to a large extent, whereas the costs per capacity of 24-, 32- and 48-layer chips exceed that of planar NAND flash memory.

Toshiba started making 3D NAND chips last spring. The Japanese company is also planning to boost the ratio of 3D NAND production by investing five trillion won or so. The ratio is to be increased from 0% to 50% between last year and next year and then to at least 80% in 2018.

Although both Toshiba and Samsung are producing 3D NAND chips based on charge trap flash, they follow a different approach. Samsung stacks control gates in a vertical direction and uses TANOS whereas Toshiba uses SONOS. It is said that Toshiba’s method is advantageous in terms of the number of stacked layers but disadvantageous in process simplicity and productivity.