NH3-plasma treatment is used to improve the quality of the gate dielectric and interface. Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density. Four groups of MOS capacitors...NH3-plasma treatment is used to improve the quality of the gate dielectric and interface. Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density. Four groups of MOS capacitors and back-gate transistors with different gate dielectrics are fabricated and their C–V and I–V characteristics are compared. It is found that the Al2O3/HfO2 back-gate transistor with NH3-plasma treatment shows the best electrical performance: high on–off current ratio of 1.53 × 107, higher field-effect mobility of 26.51 cm2/V·s, and lower subthreshold swing of 145 m V/dec.These are attributed to the improvements of the gate dielectric and interface qualities by the NH3-plasma treatment and the addition of Al2O3 as a buffer layer.展开更多
A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transisto...A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transistor after the sulfur treatment on the MoS_(2) channel is greatly enhanced due to the reduction of the sulfur vacancies during vulcanization of MoS_(2).Furthermore, as compared to those transistors with HfO2 and SiO2 as the gate dielectric, the Al2O3-gate dielectric MoS_(2) FET shows a better electrical performance after the sulfur treatment, with a lowered subthreshold swing of 179.4 m V/dec,an increased on/off ratio of 2.11 × 10^(6), and an enhanced carrier mobility of 64.74 cm^(2)/V·s(about twice increase relative to the non-treated MoS_(2) transistor with SiO2 as the gate dielectric). These are mainly attributed to the fact that a suitable k-value gate dielectric can produce a dominant dielectric-screening effect overwhelming the phonon scattering, increasing the carrier mobility, while a larger k-value gate dielectric will enhance the phonon scattering to counteract the dielectricscreening effect, reducing the carrier mobility.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61774064)
文摘NH3-plasma treatment is used to improve the quality of the gate dielectric and interface. Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density. Four groups of MOS capacitors and back-gate transistors with different gate dielectrics are fabricated and their C–V and I–V characteristics are compared. It is found that the Al2O3/HfO2 back-gate transistor with NH3-plasma treatment shows the best electrical performance: high on–off current ratio of 1.53 × 107, higher field-effect mobility of 26.51 cm2/V·s, and lower subthreshold swing of 145 m V/dec.These are attributed to the improvements of the gate dielectric and interface qualities by the NH3-plasma treatment and the addition of Al2O3 as a buffer layer.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61774064,61974048,and 61851406)。
文摘A facile method of combining the defect engineering with the dielectric-screening effect is proposed to improve the electrical performance of MoS_(2) transistors. It is found that the carrier mobility of the transistor after the sulfur treatment on the MoS_(2) channel is greatly enhanced due to the reduction of the sulfur vacancies during vulcanization of MoS_(2).Furthermore, as compared to those transistors with HfO2 and SiO2 as the gate dielectric, the Al2O3-gate dielectric MoS_(2) FET shows a better electrical performance after the sulfur treatment, with a lowered subthreshold swing of 179.4 m V/dec,an increased on/off ratio of 2.11 × 10^(6), and an enhanced carrier mobility of 64.74 cm^(2)/V·s(about twice increase relative to the non-treated MoS_(2) transistor with SiO2 as the gate dielectric). These are mainly attributed to the fact that a suitable k-value gate dielectric can produce a dominant dielectric-screening effect overwhelming the phonon scattering, increasing the carrier mobility, while a larger k-value gate dielectric will enhance the phonon scattering to counteract the dielectricscreening effect, reducing the carrier mobility.
