Development of a Quantitative Electrostatic Force Microscope

这笔拨款将帮助开发定量静电力扫描探针显微镜。该项目包括对商用超高真空扫描探针显微镜的改造和开发新的静电力显微镜模拟软件。该计划包括超高真空静电力显微镜测量以及描述尖端样品相互作用的有限元静电模拟软件的开发和测试，包括范德华和静电力贡献。这将使更多的定量了解纳米尺度的电荷分布和低迁移率的电子输运。该仪器的直接科学用途将用于加州理工学院/贝尔实验室/美国宇航局-喷气推进实验室的合作研究项目，旨在探测非易失性存储器应用中硅纳米颗粒结构中的电荷注入和存储。进行定量EFM所需的信息和软件将分发给材料研究界。电绝缘薄膜是集成电路和微机械设备等电子设备的关键和无处不在的部件。电子电荷的捕获，无论是有意的还是无意的，都是绝缘薄膜的一个共同特征。为了更好地了解绝缘薄膜的性能和可靠性，希望能够定量地测量电荷捕获的程度和机制。扫描探针显微镜技术，如静电力显微镜，为理解绝缘体中的电荷捕获开辟了新的前景，因为它们能够在纳米尺度的空间分辨率和总电荷灵敏度下到单电子水平进行测量。迄今为止，这种静电力显微镜测量已被用作定性而非定量的工具来理解绝缘体中的电荷捕获。本项目旨在通过测量和开发定量理解所需的仿真软件相结合，将静电力显微镜方法建立在牢固的定量基础上。研究结果将用于表征含有半导体纳米晶体的非易失性浮栅存储器件材料中的电荷捕获。这些材料和用它们制成的设备非常有希望成为下一代超密集、低功耗、非易失性“闪存”芯片的候选材料，就像现在广泛应用于便携式电子设备（如无线电话、寻呼机、电子相机和个人数字助理）的芯片一样。

0076486AtwaterThis grant will help develop quantitative electrostatic force scanning probe microscopy. The project includes modification of a commercial ultrahigh vacuum scanning probe microscope and development of new electrostatic force microscopy simulation software. The program comprised both ultrahigh vacuum electrostatic force microscopy measurements and development and testing of finite element electrostatic simulation software describing tip-sample interactions, including van der Waals and electrostatic force contributions . This will enable more quantitative understanding of nanometer-scale charge distributions and low mobility electronic transport. The immediate scientific use for the instrument will be in a collaborative Caltech/Bell Labs/NASA-JPL multi-investigator research program aimed at probing charge injection and storage in silicon nanoparticle structures for nonvolatile memory applications. Information and software needed to perform quantitative EFM will be disseminated to the materials research community.Electrically insulating thin films are critical and ubiquitous components of electronic devices such as integrated circuits and micromechanical devices. Trapping of electronic charge, whether by design or as an unintended effect, is a common characteristic of insulating thin films. It is desirable to be able to quantitatively measure the extent of and mechanisms for charge trapping in order to better understand the performance and reliability of insulating thin films. Scanning probe microscope techniques such as electrostatic force microscopy have opened a new vista in the understanding charge trapping in insulators because they enable measurement at nanometer-scale spatial resolution and total charge sensitivity down to the single electron level. To date, such electrostatic force microscopy measurements have been used as a qualitative but not a quantitative tool for understanding charge trapping in insulators. This project aims to put the electrostatic force microscopy method on a firm quantitative foundation, through a combination of measurements and development of simulation software needed for quantitative understanding. The results will be applied to characterize charge trapping in nonvolatile floating gate memory device materials containing semiconductor nanocrystals. These materials and the devices made with them are very promising candidates for the next-generation of ultradense, low-power nonvolatile "flash" memory chips like those now used widely in portable electronic devices such as wireless telephones, pagers, electronic cameras and personal digital assistants.