Charge Distribution Probe for the Measurement of Surface Charges, Internal Electric Fields and Related Fundamental Properties of Dielectric Materials

绝缘体的电气和电子性能是很难的 为了通过传统的方法进行测量， 绝缘体表面。 一项新技术显示出巨大的潜力。 它能够确定非接触的、以前无法测量的 材料的基本性质，特别是具有 非常低的电荷载流子浓度和半导体。 的 该技术包括测量电介质极化， 电场梯度 通过对各种成分进行反卷积 在介电极化中，体和表面贡献可以 分开 因此，获得关于表面的唯一信息 电荷，它们的符号和密度以及它们的相关 内场 该方法还高度敏感于 体极化例如可以由 缺陷和产生移动的费用。 通过应用静态 电场梯度和测量响应作为一个函数， 时间，具有长弛豫时间的过程，秒级 小时，可以进行评估。 这种过程可能是由于电荷 然而，具有非常低的漂移迁移率的载流子可以起到 决定电子产品长期稳定性的重要部分 器件或铁电体。 研究的目的是 开发一种电荷分布探针，使人们能够执行 高空间分辨率的测量，并确定 薄绝缘体层的电子性质。

The electric and electronic properties of insulators are difficult to measure by conventional methods which apply metal contacts to the insulator surfaces. A new technique has shown great potential. It enables determination of contact-free, previously unmeasurable fundamental properties of materials, especially of materials with very low charge carrier concentrations and of semiconductors. The technique consists of measuring the dielectric polarization in an electric field gradient. By deconvoluting the various components of the dielectric polarization, bulk and surface contributions can be separated. Thus, unique information is obtained about surface charges, their sign and density as well as their associated internal field. The method is also highly sensitive to changes in the bulk polarization such as may be caused by the dissociation of defects and generation of mobile charges. By applying a static electric field gradient and measuring the response as a function of time, processes with long relaxation times, of the order of seconds to hours, can be evaluated. Such processes may be due to charge carriers with very low drift mobilities which, however, may play an important part in determining the long-term stability of electronic devices or ferroelectrics. The objective of the research is to develop a Charge Distribution Probe which allows one to perform measurements with high spatial resolution and determine the electronic properties of thin insulator layers.