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Artificially introduced atomic-level sensors enable measurements of the electric field within a working semiconductor device

Semiconductors lie at the heart of many of the electronic devices that govern our daily lives. The proper functioning of semiconductor devices relies on their internally generated electric fields. Being able to measure these fields on the nanoscale is crucial for the development of next-generation electronics, but present techniques have been restricted to measurements of the electric field at a semiconductor ' s surface.
A group of Takayuki Iwasaki, Mutsuko Hatano and
vacancy( NV) centers, a type of point defect that arises
colleagues at the Tokyo Institute of Technology, the Japan
when two neighboring carbon atoms are removed from
Science and Technology Agency( JST) and Toshiharu
the diamond lattice and one of them is replaced by a
Makino at the National Institute of Advanced Industrial
nitrogen atom.
Science and Technology( AIST) has reported a new method for sensing internal electric fields at the interior of operating semiconductor devices.
NV centers can be routinely created in diamond by means of ion implantation. A nearby electric field affects an NV center ' s energy state, which in turn can be probed by a
The technique exploits the response of an artificially
method called optically detected magnetic resonance
introduced single electron spin to variations in its
( ODMR).
surrounding electric field, and enabled the researchers to study a semiconductor diode subject to bias voltages of up to 150 V.
The researchers first fabricated a diamond p-i-n diode( an intrinsic diamond layer sandwiched between an electronand a hole-doped layer) embedded with NV centers. They
Iwasaki and co-workers applied their method to diamond, a
then localized an NV center in the bulk of the i-layer,
so-called wide-band-gap semiconductor in which the
several hundreds of nanometers away from the interface,
electric fields can become very strong-- a property
and recorded its ODMR spectrum for increasing bias
important for low-loss electronic applications. Diamond
voltages. From these spectra, values for the electric field
has the advantage that it easily accommodates nitrogen-
could be obtained using theoretical formulas. The
Scigazette | 21 | February, 2017