Toshiba and Sandisk to scrap 2D NAND fab for 300mm 3D NAND

May 22, 2014 // By Julien Happich
Toshiba Corporation announced it will demolish its No. 2 semiconductor fabrication facility (Fab 2) at Yokkaichi Operations, a NAND Flash memory plant in Mie prefecture, Japan, to replace it with a new fab on the same site, dedicated to 3D NAND.

The company also entered into a non-binding memorandum of understanding with SanDisk Corporation to invest jointly in the new facility and secure space for converting existing Toshiba and SanDisk 2D NAND capacity to 3D NAND beginning in 2016.

The building of Fab2 which ended its 200mm wafer production in 2010, is currently used as an office building, and after its demolition (due to start this month), construction of a new fab should begin in September 2014, with a target completion date of Summer 2015.

Toshiba expects to begin mass production of 3D memory in the 2nd Half of FY2015, relying on existing equipments from nearby Fab3 and Fab4. The company will then transition to Fab2 to convert more 2D NAND capacity to 3D NAND as the clean room investments are finalized.

Although Toshiba's Bit Cost Scalable (BiCS) memory technology may have evolved since its first presentation in 2007, it is still under development and its full specifications are yet to be finalized. Late 2012, the company announced that it had 16-layer prototype devices based on a 50nm diameter vertical channel.

Toshiba's Bit Cost Scalable memory architecture.


Construction of the initial cleanroom is expected to be complete in time for 2016 output, with large-capacity products gradually shifting to 3D memory. But the company will keep some capacity for 2D memory to address market demand and will take further ramp up decisions on capacity conversion ramp and equipment investment from there.

The new fab will have a quake absorbing structure and an environmentally friendly design that includes LED lighting throughout the building. It will also be equipped with the latest energy saving manufacturing equipment, which will secure productivity advances while lowering power consumption. Highly efficient use of waste heat will help to lower fuel consumption and cut CO2 emissions by 15% compared to Fab 5, currently the most advanced fab on the Yokkaichi site.

Toshiba and SanDisk will, through joint ventures,