Samsung's 40nm Flash Memory

Hwang Chang-gyu

Samsung President Hwang Chang-gyu has a law: The density of the top-of-the-line flash memory chips will double every 12 months [Remember the famous Moore's Law, which says the processing power of the state-of-the-art chips will double every 18 months].

Under the stewardship of Hwang, who took the reins of Samsung's semiconductor business in 2000, the company has been realizing the projection of its boss for the last 6 years: Samsung doubled the density of the world's top-line flash memory from 256Mb in 1999, to 512Mb in 2000, 1Gb in 2001, 2Gb in 2002, 4Gb in 2003, 8Gb in 2004, 16Gb in 2005 and 32Gb this year. The new chips could be combined to make a data-storage card of up to 64 gigabytes compared with the one, two and four gigabytes of capacity common to today's storage cards.

Yesterday at its annual press conference in Seoul, Hwang unveiled a world's first 40nm, 32Gb NAND flash memory chip. High-precision machines of Samsung Electronics can now etch circuits with 40-nanometer technology, roughly one-3,000th the thickness of a human hair, on the face of silicon wafers. The manufacturing process employed a new technology, called charge trap flash (CTF), to enhance the durability of the tiny chips.

Flash memory, especially NAND-type one, has become the mainstream data storage device in almost all digital cameras, MP3 players and multimedia cell phones thanks to its characteristics of fast-read access time and solid-state shock resistance and their ability to store data even when power is switched off. NAND flash is even entering the PC computing environment led by Samsung, which came up with a pair of NAND flash-empowered laptops in June. Up until now, memory devices for computers have been the main market of hard disk drives, and memory chips have not been in competition due to their relatively small storage capacity.

Samsung will roll out the 40nm flash memories sometime in 2008. It projects that the CTF-based NAND will be refined down to 20nm within a few years.

Related News: Samsung also unveiled a new type of memory chip that it said will allow digital devices to work faster by saving new data more quickly. The phase-change random access memory, or PRAM, is nonvolatile, meaning it will retain data even when an electronic device is turned off, and is about 30 times faster than conventional flash memory, Samsung said. The company showed off a 512-megabit prototype at a press conference. It is expected to be available in 2008.

Currently, two types of nonvolatile flash memory chips — NOR and NAND — are widely used in electronic devices. NOR chips are suitable for running software directly, but are slower and more expensive to manufacture. NAND chips are easier to make in larger capacities but are more suitable for big data files, such as MP3 music. On the other hand, the memory storage device in personal computers use DRAM, or dynamic random access memory, chips.