SBIR Phase I: Development of Scanning Near Field Ultrasound Holography with Integrated Electronic Detection for Sub-Surface Nanomechanical Imaging

这个小型企业创新研究第一阶段项目将展示使用嵌入MOSFET的悬臂梁用于扫描近场超声全息(SNFUH)的悬臂梁偏转的集成电子检测的可行性。这种扫描探针显微镜(SPM)平台和扫描近场超声全息术的协同组合将提供纳米级的横向空间分辨率，并具有类似深度分辨率的潜力。SNFUH作为传统的单悬臂梁SPM平台的一部分，其性能受到限制，其中低频响应(~600 kHz)光学探测器限制了可实现的深度分辨率和吞吐量。我们建议通过开发一种全电子反馈方法来克服传统SPM平台的这一主要限制，以实现并行扫描和高分辨率SNFUH成像。这项拟议工作的核心在于“开箱即用”的创新--一种全电子的嵌入MOSFET的微悬臂梁，可以用标准的半导体技术制造。我们的初步设计已经显示出极好的灵敏度和~100 MHz的可用带宽。这项第一阶段的工作将证明高通量亚表面扫描的可行性。第二阶段的研究将集中于开发嵌入MOSFET的微悬臂梁的平行阵列。该项目更广泛的影响/商业潜力将是开发一种纳米级成像工具，该工具将立即应用于半导体行业的故障分析和工艺开发，并将在探索生物系统中工程纳米材料的相互作用方面找到用处。该工具将结合近场技术(原子力显微镜或AFM)的超高空间分辨率，以及使用超声波非破坏性地以概念简单的方式对光学致密材料(软质和硬质)内部的缺陷进行成像的能力。该项目的努力将直接导致开发一种嵌入MOSFET的高度并行的悬臂探头阵列，以及用于高分辨率和高通量SNFUH亚表面成像的全电子反馈控制。此外，我们将开发的集成电子检测方法也将应用于现有的AFM平台，从而降低它们的成本，简化它们的使用。

This Small Business Innovation Research Phase I project will demonstrate the feasibility of using MOSFET-embedded cantilevers for integrated electronic detection of cantilever deflection for scanning near-field ultrasound holography (SNFUH). This synergistic combination of the scanning probe microscopy (SPM) platform and scanning near-field ultrasound holography will provide nanoscale lateral spatial resolution, and has the potential for comparable depth resolution. The performance of SNFUH has been constrained by its implementation as part of a conventional single-cantilever SPM platform, where the low frequency response (~600 kHz) optical detector limited achievable depth resolution and throughput. We propose to overcome this major limitation to the conventional SPM platform by developing an all-electronic feedback approach to enable parallel scanning and high resolution SNFUH imaging. The core of the proposed work lies in the "out-of-the-box" innovation of an all-electronic MOSFET-embedded microcantilever that can be fabricated by standard semiconductor techniques. Our preliminary design has shown excellent sensitivity and a usable bandwidth of ~100MHz. This Phase I work will demonstrate the feasibility of high throughput sub-surface scanning. Phase II research will focus on developing a parallel array of MOSFET-embedded microcantilevers. The broader impact/commercial potential of this project will be the development of a nanoscale imaging tool which will be immediately applicable in the semiconductor industry for failure analysis and process development, and which will find utility in probing the interactions of engineered nanomaterials in biological systems. The tool will combine the ultrahigh spatial resolution of a near field technique (atomic force microscopy or AFM) with the ability to image defects inside optically dense materials (both soft and hard) using ultrasound, non-destructively and in a conceptually simple fashion. The project efforts will lead directly to the development of a highly parallel array of MOSFET-embedded cantilever probes coupled with all-electronic feedback control for high-resolution and high-throughput SNFUH sub-surface imaging. Furthermore, the method of integrated electronic detection which we will develop will also find application in existing AFM platforms, lowering their cost and simplifying their use.