ABSTRACT
This chapter reviews various approaches to create multilevel storage cells and associated challenges both for FG-NVM devices and CT-NVM devices. It discusses planar CT-MLC or UNSC cells. Now that the 20 nm product scalability has been successfully demonstrated through high volume production and 15 nm scalability challenges have been addressed, it would be reasonable to assume that the growth of such products will continue at equal or greater CGR up to 2020. The chapter discusses the scalability challenges and issues addressed from the SSD and application perspective in order to recognize the limitations and challenges that planar MLC-FGNAND FLASH need to address further down the road. Consequently, to address data integrity and reliability, technology dependent functions such as ECC and technology independent functions such as block management and drivers as well as advanced programming/reading algorithms, implementable in software/firmware had to be expanded.
