A team of researchers from Taiwan and the University of California,
Berkeley, has harnessed nanodots to create a new electronic memory
technology that can write and erase data 10-100 times faster than
today’s mainstream charge-storage memory products. The new system uses a
layer of non-conducting material embedded with discrete
(non-overlapping) silicon nanodots, each approximately 3 nm across. Each
nanodot functions as a single memory bit. To control the memory
operation, this layer is then covered with a thin metallic layer, which
functions as a “metal gate.” The metal gate controls the “on” and “off”
states of the transistor. The results are published in the American
Institute of Physics’ (AIP) journal Applied Physics Letters.
“The
metal-gate structure is a mainstream technology on the path toward
nanoscale complementary metal-oxide-semiconductor (CMOS) memory
technology,” said co-author Jia-Min Shieh, researcher, National Nano
Device Laboratories, Hsinchu, Taiwan. “Our system uses numerous,
discrete silicon nanodots for charge storage and removal. These charges
can enter (data write) and leave (data erase) the numerous discrete
nanodots in a quick and simple way.”
The
researchers were able to achieve this new milestone in speed by using
ultra-short bursts of green laser light to selectively anneal (activate)
specific regions around the metal layer of the metal gate of the
memory. Since the sub-millisecond bursts of laser light are so brief and
so precise, they are able to accurately create gates over each of the
nanodots. This method of memory storage is particularly robust, the
researchers explain, because if an individual charge in one of the
nano-sites failed, it would barely influence the others. This enables a
stable and long-lived data storage platform.
“The
materials and the processes used for the devices are also compatible
with current main-stream integrated circuit technologies,” explains
Shieh. “This technology not only meets the current CMOS process line,
but can also be applied to other advanced-structure devices.”
Source: American Institute of Physics
