TRANSFER OF SILICON THIN FILMS WITH SIO2 AND HFO2 TO C-PLANE SAPPHIRE: THE SUBSTRATE THICKNESS EFFECT ON THE FERROELECTRIC HAFNIA PROPERTIES
V.A. Antonov1, V.P. Popov1, S.M. Tarkov1, A.V. Miakonkikh2, A.A. Lomov2, K.V. Rudenko2
1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Valiev Institute of Physics and Technology, Russian Academy of Sciences, Moscow, Russia
Keywords: hydrogen transfer, silicon-on-sapphire, hafnium dioxide (hafnia), interlayer mechanical stresses, ferroelectricity
Abstract
Structural, electric, and optical studies of silicon-on-sapphire substrates with silicon and hafnia nanolayers have been carried out depending on the substrate thickness. It is shown that the biaxial tensile stress induced in the intermediate HfO2 layer - as a result of the heat treatment of such structures, due to the large difference in the thermal expansion coefficients between the layers of silicon, sapphire and hafnium dioxide, - stimulates the current hysteresis in the SOS-pseudo-MOSFET channel. It is found that a decrease in the mechanical stress in hafnium dioxide leads to an increase in the coercive field and ferroelectric switching at low fields in hafnia nanolayers.
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