Deep-level transient spectroscopy for defect characterization in dielectric materials

用于介电材料缺陷表征的深能级瞬态光谱

• 批准号: 514161805
• 负责人: Privatdozent Dr. Martin Geller
• 金额: --
• 依托单位: Forschungsgruppe Experimentalphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/514161805?language=en
• 关键词: Deep; level; transient; spectroscopy; defect

The physical properties of solid-state materials are determined, to a large extent, by defects. This is especially true for the electrical properties of semiconductors and insulators, where a variety of methods have been established to characterize defects with respect to their optical and electrical properties. The most common electrical characterization method for semiconductors is the so-called deep level transient spectroscopy (DLTS), where controlled electrical charging and discharging within a depletion region gives access to two characteristic parameters (as a fingerprint of the defect): the capture cross section and the activation energy. As conventional DLTS is limited to defects in such a space charge (depletion) region of a Schottky or p-n junction, a method for electrical defect characterization in dielectric (insulating) materials is missing. Within this project, a new method to study deep defects in dielectric materials will be further developed and optimized to characterize defects in insulators such as Al2O3, SiO2, TiO2 and GaN. It is a special optoelectrical technique that uses the boxcar evaluation method from DLTS in combination with a conductive layer (a two-dimensional electron/hole gas) that replaces the charge depletion region. The newly developed technique, called optical 2D-DLTS here, will expand the tool set for investigating defect levels in (undoped) dielectric materials. The starting point of this project will be an extension of the temperature range and bandwidth of the method, followed by an optimization of the read-out detector, i.e. the two-dimensional hole gas at the surface of an epitaxial-grown diamond layer. The long-term goal is to establish the optical 2D-DLTS method as a versatile tool to study defects in a broad range of dielectrics, grown on different detector materials (diamond, GaAs, Si, etc.).

固态材料的物理性质在很大程度上由缺陷决定。这对于半导体和绝缘体的电学性质尤其如此，其中已经建立了各种方法来表征关于其光学和电学性质的缺陷。半导体最常见的电学表征方法是所谓的深能级瞬态谱（DLTS），其中耗尽区内的受控充电和放电可以获得两个特征参数（作为缺陷的指纹）：捕获截面和激活能。由于常规DLTS限于肖特基或p-n结的这种空间电荷（耗尽）区域中的缺陷，因此缺少用于电介质（绝缘）材料中的电缺陷表征的方法。 在该项目中，将进一步开发和优化研究电介质材料中深层缺陷的新方法，以表征绝缘体中的缺陷，如Al 2 O3，SiO2，TiO 2和GaN。它是一种特殊的光电技术，使用DLTS的boxcar评估方法，并结合导电层（二维电子/空穴气）来取代电荷耗尽区。新开发的技术，称为光学2D-DLTS在这里，将扩大工具集调查（未掺杂）电介质材料的缺陷水平。该项目的起点将是该方法的温度范围和带宽的扩展，然后是读出检测器的优化，即外延生长金刚石层表面的二维空穴气体。长期目标是建立光学2D-DLTS方法作为一种多功能工具来研究在不同探测器材料（金刚石，GaAs，Si等）上生长的各种晶体中的缺陷。