Ultrathin compound semiconductor on insulator layers for high-performance nanoscale transistors.
Over the past several years, the inherent scaling limitations of silicon (Si) electron devices have fuelled the exploration of alternative semiconductors, with high carrier mobility, to further enhance device performance. In particular, compound semiconductors heterogeneously integrated on Si substrates have been actively studied: such devices combine the high mobility of III-V semiconductors and the well established, low-cost processing of Si technology. This integration, however, presents significant challenges. Conventionally, heteroepitaxial growth of complex multilayers on Si has been explored-but besides complexity, high defect densities and junction leakage currents present limitations in this approach. Motivated by this challenge, here we use an epitaxial transfer method for the integration of ultrathin layers of single-crystal InAs on Si/SiO(2) substrates. As a parallel with silicon-on-insulator (SOI) technology, we use 'XOI' to represent our compound semiconductor-on-insulator platform. Through experiments and simulation, the electrical properties of InAs XOI transistors are explored, elucidating the critical role of quantum confinement in the transport properties of ultrathin XOI layers. Importantly, a high-quality InAs/dielectric interface is obtained by the use of a novel thermally grown interfacial InAsO(x) layer (~1 nm thick). The fabricated field-effect transistors exhibit a peak transconductance of ~1.6 mS µm(-1) at a drain-source voltage of 0.5 V, with an on/off current ratio of greater than 10,000.
Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA.
Hyunhyub
H
Ko
Kuniharu
K
Takei
Rehan
R
Kapadia
Steven
S
Chuang
Hui
H
Fang
Paul W
PW
Leu
Kartik
K
Ganapathi
Elena
E
Plis
Ha Sul
HS
Kim
Szu-Ying
SY
Chen
Morten
M
Madsen
Alexandra C
AC
Ford
Yu-Lun
YL
Chueh
Sanjay
S
Krishna
Sayeef
S
Salahuddin
Ali
A
Javey