【作者】 陈二柱；

【导师】 施卫；

【作者基本信息】 西安理工大学 ， 微电子学与固体电子学， 2002， 硕士

【摘要】 在兼顾电脉冲功率和带宽两方面，光电导开关是最有效的微波辐射源。然而，由于GaAs材料的固有特性，半绝缘GaAs光电导开关在其工作性能上有明显的优点，特别是在一定的光能和电场阈值条件下，GaAs光电导开关能产生Lock-on效应现象，所以GaAs光电导开关的器件研究和实际应用开发成为光电导开关研究者所关注的焦点。然而到目前为止，没有一种完善的理论模型，能对半绝缘GaAs光电导开关中发现的Lock-on效应进行较全面的解释。 作者测试了半绝缘GaAs光电导开关在线性、非线性以及从线性到非线性过渡的临界状态模式下输出的电脉冲波形，特别是反复测量了开关在临界状态下的偏置电场阈值和Lock-on电场强度。本文基于GaAs等Ⅲ—Ⅴ族化合物半导体的转移电子理论，结合半绝缘GaAs光电导开关中特有的Lock-on效应的研究，提出了类似于耿畴(高场畴或偶极畴)的单极电荷畴理论模型，对光电导开关Lock-on效应的各种现象给出了理论解释。由于单极电荷畴内电场强度增大，从而导致开关体内载流子雪崩倍增和辐射复合，引发了Lock-on效应的特有现象。当触发光脉冲消失后，单极电荷畴内雪崩电离和辐射复合在开关体内形成了载流子高导电通道，成为了载流子倍增的源泉，控制着Lock-on电流。应用单极电荷畴模型数值计算了Lock-on效应的光、电时间延迟和载流子的渡 西安理工大学硕士学位论文越速度（丝状电流穿越开关间隙的速度），所得计算结果与实验测试结果基本吻A 利川半绝缘GaAs光屯导开关的超快光l匕11向应灯性，成功地应川下纳秒激光脉冲展宽试验中，证明了开关可厂泛应川在超快光电响应和光电反馈网络中。更多还原

【Abstract】 THE TRANSIENT STUDY ON GALLIUM ARSENIDEPHOTOCONDUCTIVE SWITCHES Speciality: Microelectronics Candidate: (signature) Supervisor: (signature)As far as the power and band width of electronic pulses are concerned, optically controlled Photoconductive Semiconductor Switches (PCSS’s) are the most effective microwave radiant sources. Due to the intrinsic characteristics of the GaAs material, Semi-insulating (SI) GaAs PCSS’s have more obvious advantages in the performance of both high power and ultra-fast switching than those PCSS’s made of other materials. The GaAs PCSS’s can take on the particular phenomenon of Lock-on effect when the thresholds of activating optical energy and bias field, which the devices demand, are meted simultaneously. Accordingly, the great importance was attached to the device research and application of the GaAs PCSS’s. Up to the present, there are no reliable theories that can correctly account for the observed transient characteristics produced by the Lock-on effect.The electronic pulse waveform of linear, non-linear and the critically transiting switching modes outputted from the SI-GaAs PCSS’s was observed and measured. Especially, we repeatedly measured the bias field thresholds and Lock-on field of the critical transiting mode from the linear to non-linear state. Based on the transferred-electron theory of the III-V compound semiconductor and the research on the Lock-on effect of the SI-GaAs PCSS’s, this paper proposes the monopole charge domain model similar to the Guun or high-field domain to explain the peculiar switching phenomena occurring in the Lock-on mode theoretically. Owing to the field enhancement in the domain, the avalanching gain and recombination radiation are induced and the switches occur the special phenomenon of the Lock-on effect. When the triggering light goes, the avalanche impact ionization and recombination radiation in the domain result in the formation of the carriers’ conductive channel in the body of the devices and control the current of the Lock-on switching. Based on the theory mode, the delay time between the beginning of optical illumination and the onset of Lock-on switching was calculated, and the transiting speed of electrons, the traversing velocity of the current filament, was obtained as well. The calculated results matched well the experimental results.Taking advantage of the ultra-fast response characteristics of the devices, SI-GaAs PCSS’s are successfully applied to the broadening test of nanosecond laser pulses. Our tests show that the switches could be used in the ultra-fast photoelectric response and the photoelectric feedback net.更多还原