Abstract

Experimental studies of n⁺-GaAs/n⁰-GaAs/n⁺-GaAs isotype heterostructures with a 100-nm-thick wide-gap N⁰-AlGaAs barrier situated in the n⁰-GaAs region are carried out. It is shown that the current–voltage characteristic of the structures under study has a negative-differential-resistance (NDR) portion, with the transition to this region occurring with a time delay that may reach tens of nanoseconds. It is found that operation in the NDR region is associated with the onset of impact-ionization process. Numerical analysis in terms of the energy-balance model demonstrated that the transition to the NDR region is associated with the formation of an electric field domain that covers a part of the lightly doped region between the thin wide-gap N⁰-AlGaAs barrier and the heavily doped n⁺-GaAs layer and with the onset of impact ionization at the interface with the heavily doped n⁺-GaAs layer. A comparative analysis of the experimental data and the modeling results showed that, for the current–voltage characteristics of the heterostructures under study to be correctly described, the model should take into account the less pronounced ability of a heterojunction to restrict carrier transport in the barrier layer.

中文翻译：

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n + -GaAs / n 0 -GaAs / n + -GaAs同型异质结构中具有宽间隙AlGaAs薄阻挡层的载流子传输过程

摘要

n ⁺ -GaAs / n ⁰ -GaAs / n ⁺ -GaAs同种异质结构的实验研究，该结构具有位于n ⁰处的厚100纳米宽间隙N ⁰ -AlGaAs势垒-GaAs区域被执行。结果表明，所研究结构的电流-电压特性具有负微分电阻（NDR）部分，向该区域的过渡发生时延可能会达到数十纳秒。发现在NDR区域中的操作与碰撞电离过程的开始有关。根据能量平衡模型进行的数值分析表明，向NDR区域的过渡与电场域的形成有关，该电场域覆盖了薄的宽能隙N ⁰ -AlGaAs势垒与N原子之间的轻掺杂区域的一部分。重掺杂n ⁺ -GaAs层，并在与重掺杂n的界面处发生碰撞电离⁺ -GaAs层。对实验数据和建模结果的比较分析表明，为了正确描述正在研究的异质结构的电流-电压特性，该模型应考虑异质结限制势垒中载流子传输的较弱能力。层。