【摘要】 基于等离子轰击和射频磁控溅射技术,制备了HfO₂/SrTiO₃结构的全氧化物场效应晶体管（FET）,并研究了其栅极漏电性质。该全氧化物晶体管的制备工艺均在室温条件下完成,包括Ar⁺轰击在SrTiO₃单晶表面产生的导电沟道,溅射生长非晶HfO₂薄膜作为栅极介质层。实验发现溅射工艺中的氧分压对HfO₂栅极漏电性质的影响显著。当氧氩分压比从1∶10增加到1∶2时,HfO₂栅极的漏电密度明显降低。对变温漏电数据的分析表明,HfO₂栅极的漏电以空间电荷限制电流（SCLC）机制为主导。对于低氧分压制备的栅极,其SCLC漏电机制的特征温度（T_t）和缺陷密度（N_t）分别为796 K和5.3×10¹⁸ cm^-3。而氧分压提高后,栅极SCLC漏电的T_t降低为683 K,同时N_t下降为1.2×10¹⁸ cm^-3。T_t的变化表明缺陷在禁带中分布发生变化,引起漏电-电压关系（J-U^m）中的指数项m减小,有效地降低了栅极漏电,显著提高了HfO₂/SrTiO₃场效应晶体管的性能,使其开关比达到10⁴。更多还原

【Abstract】 This article investigated the leakage properties of the all-oxide field-effect transistors（FET） based on HfO₂/SrTiO₃ structure, which was fabricated at room temperature. The conducting channel on the surface of SrTiO₃ single crystal was formed by the Ar⁺ bombardment. The amorphous HfO₂ gate was deposited by radio frequency sputtering. The oxygen partial pressure during the sputtering plays a crucial role to determine the leakage property of HfO₂ gate dielectrics. By increasing the oxygen partial pressure from 1∶10 to 1∶2, the leakage current density is reduced significantly. From 150 K to 300 K, the leakage of HfO₂ gate dielectrics is dominated by space charge limiting current（SCLC）. At lower oxygen partial pressure, the characteristic temperature（T_t） of SCLC and the defect density（N_t） are extracted to be 796 K and 5.3×10¹⁸ cm^-3 respectively. By increasing the oxygen partial pressure, T_t is reduced to 683 K, and N_t is reduced to 1.2×10¹⁸ cm^-3. Reduction of T_t is due to the change of trap distribution in energy band, which leads to the decrease of exponential term m（J-U^m）. The improvement of leakage is mainly caused by the change of exponential term m by increasing the oxygen partial pressure. This improves the performance of the HfO₂/SrTiO₃ FET, for example, with enhanced On-Off ratio up to 10⁴.更多还原