16:00 〜 18:00
▲ [25p-P10-1] Development of TEM-MCBJ method and measurement of piezoresistive effect for semiconductor nanowires
キーワード：In situ TEM, Si NW, Stretching
As a typical semiconductor material, silicon (Si) has extensive commercial applications in the areas of semiconductor devices and integrated circuits. In recent decades, with miniaturization of electronic devices, the development and analysis of Si nanowires (NWs) have been vigorously carried out. Si crystal has low ductility at room temperature, while it has been found to be more deformable when their characteristic sizes are reduced to below 100 nm, showing much higher elasticity compared to their bulk. As concerned with the electronic structure, the bandgap and carrier mobility of Si NWs are expected theoretically to be modified by elastic deformation. Recently, the Si NWs showed a large piezoelectric effect by stretching compared to their bulk. However, the relationship between stress (strain) and resistivity has not been systematically investigated. Thus, it has been still required to investigate the relationship between the strain and electronic properties of Si NWs.
In this research, we will investigate the relationship between the strain and electronic properties of a Si NW, by measuring the electrical conductance simultaneously with observing the atomic structure. To realize it, we designed and fabricated an in-situ TEM holder equipped with a mechanically controllable breaking junction (MCBJ) setup, called TEM-MCBJ holder.
To evaluate the stability of the TEM-MCBJ holder, we carried out an in situ stretching test of Si nanowire. The TEM image showed clear lattice fringes, indicating that the holder is stable enough to obtain the atom-resolved TEM images. In-situ deformation processes and electrical measurements were carried out in the TEM. And the relationships between the applied voltage and electrical current (I-V curves) during stretching were measured. We found that the conductance decreased with increasing the tensile strain. Such a phenomenon is not consistent with the previous reports.
In this research, we will investigate the relationship between the strain and electronic properties of a Si NW, by measuring the electrical conductance simultaneously with observing the atomic structure. To realize it, we designed and fabricated an in-situ TEM holder equipped with a mechanically controllable breaking junction (MCBJ) setup, called TEM-MCBJ holder.
To evaluate the stability of the TEM-MCBJ holder, we carried out an in situ stretching test of Si nanowire. The TEM image showed clear lattice fringes, indicating that the holder is stable enough to obtain the atom-resolved TEM images. In-situ deformation processes and electrical measurements were carried out in the TEM. And the relationships between the applied voltage and electrical current (I-V curves) during stretching were measured. We found that the conductance decreased with increasing the tensile strain. Such a phenomenon is not consistent with the previous reports.