注氟MOSFET电离辐射响应特性

Ionizing Radiation Responses of MOSFET Implanted Fluorine

对氢氧合成栅氧化后注F的MOSFET进行了γ射线辐照试验,分析了不同注F剂量的MOSFET电离辐射响应特性。结果表明,在1×10^(15)～1×10^(16)F/cm^2F注量范围内,注F能够明显抑制辐射感生氧化物电荷和界面态的增长,且F注量越高,抑制能力越强,F的注入能减少工艺过程所带来的氧化物电荷和界面态。用Si一F结键替代其它在辐射过程中易成为电荷陷阱的应力键模型对实验结果进行了讨论。可以预测,F在Si/SiO_2界面附近和SiO_2中的行为直接与MOS结构的辐射响应相对应,而F的行为依赖于注F工艺条件。

r-ray irradiation effects on F implanted N-channel MOSFET with pyrogenetic gate oxides have been investigated. It is found that implanting F into gate oxides has an obvi-ous feature of restraining radiation-induced oxide charges and interface states in the dose of 1 × 1015-1 × 1016 F/cm2 ,and the higher F implantation dose, the better the restraining result is,the oxide charges and interface states due to fabrication can be reduced by means of F implantation. The radiation-induced charges and interface states are supressed by forming Si-F bonds to substitute the other strained bonds,which are easy to become charge traps under irradiation. It can be expected that the acts of fluorine on the interface of Si/SiO2 and in the SiO2 film are responsible to the radiation effects of MOS structures and depend on the technology of F implantation.