SBIR Phase II: Flux-Gated Spin-Dependent-Tunneling Sensors

这项小型企业创新研究二期项目旨在制造一种新型纳米技术自旋相关隧道（SDT）磁场传感器设备，该设备在低频下具有更高的信噪比性能。在大量的应用市场中，低频分辨率的提高是非常需要的。所提出的装置基于调制集成磁通集中器的磁导率和/或通过的磁通的创新方法。这些“磁通门控”（截断或扫描由SDT换能器感测的磁场）的方法采用片上微加工线圈结构。该项目探索了SDT设备固有的频率相关（或1/f）噪声的本质，并提供了一种集成的低功耗降噪方法。SDT技术处于磁阻传感器发展的前沿，部分原因是其磁阻可以是最好的巨磁阻器件的3倍以上，是当今市场上各向异性磁阻传感器的15倍以上。第二阶段的设备是基于新颖的专有概念，用于推进小型，固态，低成本，低功耗的磁场传感器。主要的需求是高分辨率的磁场传感器，这种传感器更具可现场性和成本效益。SDT技术提供了这种高分辨率的潜力，以及用于SDT微传感器的硅制造方法的低成本优势。这些传感器的应用包括无损检测、安全和监视以及磁介质验证。这些非常多样化的应用中的每一个都有一个共同的需求，即提出的小型，高灵敏度，低功率磁场传感设备。新设备将使这些领域扩展到小型便携式应用，并进入成本效益低场传感无法实现的领域。

This Small Business Innovation Research Phase II project seeks to fabricate a novel nanotechnology spin-dependent tunneling (SDT) magnetic field sensor device with increased signal-to-noise performance at low frequencies. The increased resolution at low frequencies is greatly desired in a large number of application markets. The proposed device is based on innovative methods of modulating the permeability of, and/or the flux through, integrated flux concentrators. These methods of "flux gating" (chopping or sweeping the magnetic field which is sensed by the SDT transducers) are employed using on-chip, microfabricated coil structures. The project explores the nature of frequency-dependent (or 1/f) noise that is intrinsic to SDT devices, and offers an integrated low-power method of noise reduction. SDT technology is at the leading edge of magnetoresistive transducer development due, in part, to the fact that its magnetoresistance can be more than 3 times that of the best giant magnetoresistive devices, and more than 15 times that of the anisotropic magnetoresistive sensors on the market today.The devices for this Phase II is based on novel and proprietary concepts for the advancement of small, solid-state, low-cost, low-power magnetic field sensors. The primary need is for high-resolution magnetic field sensors that are more fieldable and cost effective. SDT technology offers this high-resolution potential as well as the low-cost advantages of silicon fabrication methods used for SDT micro-sensors. Applications for these sensors include non-destructive testing, security and surveillance, and magnetic media validation. Each of these very diverse applications share a common need for the small, highly sensitive, low power magnetic field sensing devices being proposed. The new devices will enable each of these areas to expand into small portable applications and into areas where cost effective low-field sensing has not been possible.