通过理论计算,对比分析了不同界面层对金属与n型锗(Ge)接触的影响。结果表明,界面层有利于降低费米能级钉扎效应,使金属与n型Ge接触的电子势垒高度降低。然而,由于界面层与Ge的导带之间存在带阶,界面层额外增加了不利的隧穿电阻。优化...通过理论计算,对比分析了不同界面层对金属与n型锗(Ge)接触的影响。结果表明,界面层有利于降低费米能级钉扎效应,使金属与n型Ge接触的电子势垒高度降低。然而,由于界面层与Ge的导带之间存在带阶,界面层额外增加了不利的隧穿电阻。优化选择合适的界面层材料,降低电子势垒高度的同时减小隧穿电阻,有利于减小比接触电阻率。采用厚度为1.5 nm的Zn O作界面层,电子势垒高度为0.075 e V,比接触电阻率为2×10-8Ω·cm2,比无界面层的0.26Ω·cm2降低了7个数量级。展开更多
The electrical properties of Ni0.95Pt0.05-germanosilicide/Si1_xGex contacts on heavily doped p-type strained Sil-xGex layers as a function of composition and doping concentration for a given composition have been inve...The electrical properties of Ni0.95Pt0.05-germanosilicide/Si1_xGex contacts on heavily doped p-type strained Sil-xGex layers as a function of composition and doping concentration for a given composition have been investigated. A four-terminal Kelvin-resistor structure has been fabricated by using the conventional com- plementary metal-oxide-semiconductor （CMOS） process to measure contact resistance. The results showed that the contact resistance of the Ni0.95Pt0.05-germanosilicide/Sil-xGex contacts slightly reduced with increasing the Ge fraction. The higher the doping concentration, the lower the contact resistivity. The contact resistance of the samples with doping concentration of 4×10^19 cm^-3 is nearly one order of magnitude lower than that of the sam- ples with doping concentration of 5 × 10^17 cm^-3. In addition, the influence of dopant segregation on the contact resistance for the lower doped samples is larger than that for the higher doped samples.展开更多
We have studied erbium germanosilicide (ErSiGe) Ohmic contacts on n-type Si_(1-x)Ge_x substrates with differing Ge concentrations (0≤x≤0.3).Thin layers of Ti (20 nm)/Er (20 nm) were deposited on Si_(1-x)Ge_x substra...We have studied erbium germanosilicide (ErSiGe) Ohmic contacts on n-type Si_(1-x)Ge_x substrates with differing Ge concentrations (0≤x≤0.3).Thin layers of Ti (20 nm)/Er (20 nm) were deposited on Si_(1-x)Ge_x substrates and then post-annealed at 600°C for 60 s to form a stable ErSiGe film.The structures of the ErSiGe films and ErSiGe/Si_(1-x)Ge_x interfaces were characterized by Transmission Electron Microscopy measurements (TEM).The TEM images showed that the thicknesses of ErSiGe films and the Si_(1-x)Ge_x substrates were about 60 and 50 nm,respectively.The ErSiGe/Si_(1-x)Ge_x structure had a smooth interface.Moreover,no agglomeration or Ge segregation was observed.The contact resistivity of the ErSiGe/Si_(1-x)Ge_x structures was measured by the specially designed four-terminal Kelvin structures.When the Ge concentration of Si_(1-x)Ge_x substrates increased from 10% to 30%,the specific contact resistivity (c) slightly decreased from 9.0×10 7 ·cm 2 to 7.4×10 7 ·cm 2,indicating that the Ge concentration is not the main effect on the c of the ErSiGe/Si_(1-x)Ge_x Ohmic contacts.展开更多
文摘通过理论计算,对比分析了不同界面层对金属与n型锗(Ge)接触的影响。结果表明,界面层有利于降低费米能级钉扎效应,使金属与n型Ge接触的电子势垒高度降低。然而,由于界面层与Ge的导带之间存在带阶,界面层额外增加了不利的隧穿电阻。优化选择合适的界面层材料,降低电子势垒高度的同时减小隧穿电阻,有利于减小比接触电阻率。采用厚度为1.5 nm的Zn O作界面层,电子势垒高度为0.075 e V,比接触电阻率为2×10-8Ω·cm2,比无界面层的0.26Ω·cm2降低了7个数量级。
基金Project supported by the National Natural Science Foundation of China(No.11004251)the Development Foundation of China University of Petroleum(Beijing)(No.01JB021)
文摘The electrical properties of Ni0.95Pt0.05-germanosilicide/Si1_xGex contacts on heavily doped p-type strained Sil-xGex layers as a function of composition and doping concentration for a given composition have been investigated. A four-terminal Kelvin-resistor structure has been fabricated by using the conventional com- plementary metal-oxide-semiconductor （CMOS） process to measure contact resistance. The results showed that the contact resistance of the Ni0.95Pt0.05-germanosilicide/Sil-xGex contacts slightly reduced with increasing the Ge fraction. The higher the doping concentration, the lower the contact resistivity. The contact resistance of the samples with doping concentration of 4×10^19 cm^-3 is nearly one order of magnitude lower than that of the sam- ples with doping concentration of 5 × 10^17 cm^-3. In addition, the influence of dopant segregation on the contact resistance for the lower doped samples is larger than that for the higher doped samples.
文摘We have studied erbium germanosilicide (ErSiGe) Ohmic contacts on n-type Si_(1-x)Ge_x substrates with differing Ge concentrations (0≤x≤0.3).Thin layers of Ti (20 nm)/Er (20 nm) were deposited on Si_(1-x)Ge_x substrates and then post-annealed at 600°C for 60 s to form a stable ErSiGe film.The structures of the ErSiGe films and ErSiGe/Si_(1-x)Ge_x interfaces were characterized by Transmission Electron Microscopy measurements (TEM).The TEM images showed that the thicknesses of ErSiGe films and the Si_(1-x)Ge_x substrates were about 60 and 50 nm,respectively.The ErSiGe/Si_(1-x)Ge_x structure had a smooth interface.Moreover,no agglomeration or Ge segregation was observed.The contact resistivity of the ErSiGe/Si_(1-x)Ge_x structures was measured by the specially designed four-terminal Kelvin structures.When the Ge concentration of Si_(1-x)Ge_x substrates increased from 10% to 30%,the specific contact resistivity (c) slightly decreased from 9.0×10 7 ·cm 2 to 7.4×10 7 ·cm 2,indicating that the Ge concentration is not the main effect on the c of the ErSiGe/Si_(1-x)Ge_x Ohmic contacts.
