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TAP TIMES -34- AUGUST 2022
Ultrathin capacitor could First discov-
enable energy-efficient chips ered more than
80 years ago,
BERKELEY, Calif. — The silicon-based barium titanate
computer chips that power our mod- (BaTiO3) found
ern devices require vast amounts of use in various
energy to operate. capacitors for
electronic cir- Electronic microscope images show
Despite ever-improving computing effi- cuits, ultrasonic the precise atom-ty-atom structure
ciency, information technology is projected generators, of a barium titanate thin film sand-
to consume around 25% of all primary transducers, wiched between layers of strontium
energy produced by 2030. and even so- ruthenate metal to make a tiny ca-
nar. pacitor. (LBL)
Need for computing power
Researchers in the microelectronics and Orientation flip-flopped
materials sciences communities are seek- Crystals of the material respond quickly to
ing ways to sustainably manage the global a small electric field, flip-flopping the ori-
need for computing power. entation of the charged atoms that make
up the material in a reversible but perma-
The holy grail for reducing this digital de- nent manner even if the applied field is
mand is to develop microelectronics that removed.
operate at much lower voltages, which
would require less energy and is a primary This provides a way to switch between the
goal of efforts to move beyond today’s proverbial “0” and “1” states in logic and
state-of-the-art CMOS (complementary memory storage devices — but still re-
metal-oxide semiconductor) devices. quires voltages larger than 1,000 millivolts
(mV) for doing so.
Non-silicon materials with enticing proper-
ties for memory and logic devices exist; Seeking to harness these properties for
but their common bulk form still requires use in microchips, the Berkeley Lab-led
large voltages to manipulate, making them team developed a pathway for creating
incompatible with modern electronics. films of BaTiO3 just 25 nanometers thin –
less than a thousandth of a human hair’s
Thin-film alternatives width — whose orientation of charged
Designing thin-film alternatives that not atoms, or polarization, switches as quickly
only perform well at low operating voltag- and efficiently as in the bulk version.
es but can also be packed into microelec-
tronic devices remains a challenge. “We’ve known about BaTiO3 for the better
part of a century and we’ve known how to
Now, a team of researchers at Lawrence make thin films of this material for over 40
Berkeley National Laboratory (Berkeley years. But until now, nobody could make
Lab) and UC Berkeley have identified one a film that could get close to the structure
energy-efficient route by synthesizing a or performance that could be achieved in
thin-layer version of a well-known material bulk,” said Lane Martin, a faculty scientist
whose properties are exactly what’s need- in the Materials Sciences Division (MSD) at
ed for next-generation devices. Berkeley Lab. next page
