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

用于测量表面电荷、内部电场和相关基本特性的电荷分布探头

• 批准号: 9403456
• 负责人: Friedemann Freund
• 金额: $ 27.61万
• 依托单位: Phytron Instruments Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 1997-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9403456&HistoricalAwards=false
• 关键词: Charge; Distribution; Probe; Measurement; Surface

The main objective of the Phase II SBIR award is to develop a Fringe Field Charge Distribution Probe (FF-CDP) that is capable of performing measurements with moderate to high spatial resolution and extremely good long-term stability. Electric and electronic properties of insulators are difficult to measure by conventional methods which apply metal contacts to the insulator surfaces. This new technique has shown great potential. It allows one to measure, contact-free under minimum perturbation conditions, previously unmeasureable fundamental properties of materials, especially of materials with very low charge carrier concentrations. The technique relies on 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 fields. This method is sensitive to changes in the bulk polarization, due to structural changes, to phase transitions, and to defects that generate mobile charges. By applying a static electric field gradient and measuring the response as function of time, processes with long relaxation times, of the order of seconds to hours, can be assessed. Such processes are often due to charge carriers with low drift mobilities, which may play an important part in determining the long-term stability of insulators, ferroelectrics and other components of semiconductor devices.

第二阶段 SBIR 奖项的主要目标是开发一种边缘场电荷分布探针 (FF-CDP)，该探针能够以中等到高空间分辨率和极好的长期稳定性进行测量。 绝缘体的电气和电子特性很难通过在绝缘体表面施加金属接触的传统方法来测量。 这项新技术显示出巨大的潜力。 它允许人们在最小扰动条件下以非接触方式测量以前无法测量的材料的基本特性，特别是载流子浓度非常低的材料。 该技术依赖于电场梯度中的电介质极化。 通过对介电极化的各个分量进行解卷积，可以分离体和表面的贡献。 因此，可以获得关于表面电荷、它们的符号和密度以及它们相关的内部场的独特信息。 该方法对由于结构变化、相变以及产生移动电荷的缺陷而引起的体极化变化敏感。 通过施加静电场梯度并测量作为时间函数的响应，可以评估具有长弛豫时间（数秒到数小时）的过程。 这种过程通常是由于电荷载流子的漂移迁移率较低，这可能在确定绝缘体、铁电体和半导体器件其他组件的长期稳定性方面发挥重要作用。