Estimation of overgrown semiconductor interfaces with buried fine metal patterns by using resonant properties of electron wave

在超晶格结构的量子效应器件中，异质结中的导带偏移对器件的特性有很大的影响。提出了一种利用共振隧穿二极管（RTD）测量导带偏移（ΔEc）的方法。当三势垒RTD处于非谐振状态时，势垒上的电子发射成为电流的主要成分，并受到ΔEc的限制。基于电子发射理论，可以通过测量200 K以上的电流-电压特性的温度依赖性来估计ΔEc。该方法被应用于GaAsP/GaAs TBRTD，Δec估计为约200 meV。该方法适用于势垒层存在应变的情况，量子能级的展宽是提高量子效应器件性能的关键参数之一。本文提出了一种利用双势垒RTD分别计算均匀展宽和非均匀展宽的方法，将双势垒RTD的透过率看作是一个洛伦兹函数和一个高斯函数的卷积。将该方法应用于GaAsP/GaAsDBRTDs，在G=8.4[meV]的情况下，分别估算出了Γh和Γi为3.3[meV]和7.4 [meV]。门依赖性表明，数据来源于一个耦合的量子系统，包括量子点和量子化的接触区域。

In quantum effect devices with superlattice structure, conduction band offset in heterojunction greatly affects the characteristics. We propose a method for evaluating the conduction band offset (ΔEc) by using resonant tunneling diodes (RTD). If the triple-barrier (TB) RTDs are off-resonance condition, thermionic emission over the barriers becomes a main component for a current, which is restricted by ΔEc. The ΔEc can be estimated by measuring temperature dependence above 200K of the current-voltage characteristics, based on thermionic emission theory. The method was applied for a GaAsP/GaAs TBRTD and the Δec was estimated as about 200 meV. This method is applicable for a case that the barrier layer has strain.A broadening of the quantum energy level (Γ) is one of a key parameter for improving quantum effect devices. We proposed a method for evaluating a homogeneous broadening (Γh) and inhomogeneous broadening (Γi) independently by using double-barrier (DB) RTD, where we regard the transmittance of DBRTD as the convolution of a Lorentzian and a Gaussian. The method was applied for GaAsP/GaAs DBRTDs, and the Γh, Γi were independently estimated as 3.3[meV] and 7.4 [meV] for G=8.4[meV] We fabricated a vertical GaInP/GaAs double barrier structure with a self-aligned buried tungsten gate providing lateral construction. The gate dependence indicates that the data originate from a coupled quantum system including a quantum dot and quantized contact regions.