ZnO thin film transistor with high-k NbLaO/SiO2 bilayer gate dielectric was fabricated by sputtering, and the temperature dependence of the electrical properties of the device was investigated in the temperature range of 293–353 K for clarifying thermally activated carrier generation and carrier transport mechanisms in the conducting channel. With the increase in the temperature, the transfer curve shifts toward the negative gate voltage direction with a negative shift of the threshold voltage, an increase in the off-state current and the subthreshold slope, and a significant increase in carrier mobility. The decrease in the threshold voltage is originated from the formation of oxygen vacancy and the release of free electrons in the ZnO channel, and the formation energy can be estimated to be approximately 0.3 eV. In both subthreshold and above-threshold regimes, the temperature dependence of the drain current shows Arrhenius-type dependence, and the activation energy is around 0.94 eV for a gate voltage of 2 V, reducing with the increase in the gate voltage. The temperature dependence of the ZnO film resistance also exhibits an Arrhenius-type behavior, indicating that the thermal activation conduction process is the dominant conduction mechanism in the ZnO film. Two types of thermal activation conduction processes are observed in the 303–373 K temperature range. This is explained in terms of the existence of two types of deep donors that are consecutively excited to the conduction band as the temperature increases.

中文翻译：

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具有高 k NbLaO 栅极电介质的 ZnO 薄膜晶体管的电特性的温度依赖性

通过溅射制备具有高 k NbLaO/SiO2 双层栅极电介质的 ZnO 薄膜晶体管，并在 293-353 K 的温度范围内研究了器件电学特性的温度依赖性，以阐明热激活载流子的产生和载流子传输传导通道中的机制。随着温度的升高，转移曲线向负栅极电压方向移动，阈值电压负移，关态电流和亚阈值斜率增加，载流子迁移率显着增加。阈值电压的降低源于氧化锌通道中氧空位的形成和自由电子的释放，形成能估计约为0.3 eV。在阈值以下和阈值以上两种状态下，漏极电流的温度依赖性都显示出阿伦尼乌斯型依赖性，并且对于 2 V 的栅极电压，活化能约为 0.94 eV，随着栅极电压的增加而降低。ZnO 薄膜电阻的温度依赖性也表现出 Arrhenius 型行为，表明热激活传导过程是 ZnO 薄膜中的主要传导机制。在 303-373 K 温度范围内观察到两种类型的热激活传导过程。这是根据存在两种类型的深施主来解释的，它们随着温度的升高而连续激发到导带。2 V 的栅极电压为 94 eV，随着栅极电压的增加而降低。ZnO 薄膜电阻的温度依赖性也表现出 Arrhenius 型行为，表明热激活传导过程是 ZnO 薄膜中的主要传导机制。在 303-373 K 温度范围内观察到两种类型的热激活传导过程。这是根据存在两种类型的深施主来解释的，它们随着温度的升高而连续激发到导带。2 V 的栅极电压为 94 eV，随着栅极电压的增加而降低。ZnO 薄膜电阻的温度依赖性也表现出 Arrhenius 型行为，表明热激活传导过程是 ZnO 薄膜中的主要传导机制。在 303-373 K 温度范围内观察到两种类型的热激活传导过程。这是根据存在两种类型的深施主来解释的，它们随着温度的升高而连续激发到导带。在 303-373 K 温度范围内观察到两种类型的热激活传导过程。这是根据存在两种类型的深施主来解释的，它们随着温度的升高而连续激发到导带。在 303-373 K 温度范围内观察到两种类型的热激活传导过程。这是根据存在两种类型的深施主来解释的，它们随着温度的升高而连续激发到导带。