Nitride -based Cold Cathodes for Microdevice Applications

该项目开发了能够在近大气压和化学活性环境下工作的氮基冷阴极电子发射器，并为这些设备制定了商业上可行的制造技术。今后将重点研究纳米硼/氮化碳（BN/CN）材料。即使在相对高压的环境下，它们也具有低导通场强和高发射电流，是场发射极器件的优秀候选者。两者都表现出优异的化学、热和机械稳定性，高溅射电阻，因此阴极寿命更长。它们与传统的硅衬底兼容，允许直接与激励电路，放大器和信号调节器的设备集成。它们是金刚石和其他碳基薄膜的优越替代品，更容易沉积和定型，并且更耐氧气和水蒸气的侵蚀。一些关键的电子性质将通过生长后修饰技术得到优化。离子注入和x射线和准分子激光照射将用于降低阈值电压，而不会对发射稳定性产生有害的变化。我们还将模拟这些薄膜中的电子发射过程。我们的模型将涵盖从衬底到发射层的电子注入，电子在材料中的传输，最后发射到真空中。当然，我们希望研究的建模和表征阶段能够相互反馈，最终形成一种有效的设备设计工具。该项目的最后阶段将是开发基于氮化物的压力传感器。与目前的技术相比，这些微传感器可以在几十年的压力下进行精确、准确和可重复的压力测量。它们还具有在腐蚀性和高温环境中集成的潜力。最后，驱动和传感电子器件可以集成在同一个芯片上，比目前传统的电容式和压电式传感器要简单得多。

The project develops nitride-based cold cathode electron emitters capable of operating under near-atmospheric pressure and in chemically active environments, and works out commercially feasible fabrication techniques for these devices. Efforts will be concentrated on nanocrystalline boron/carbon nitride (BN/CN) materials. These are excellent candidates for field emitter devices, with low turn-on field strengths and high emission currents, even in relatively high-pressure regimes. Both show excellent chemical, thermal, and mechanical stability, high sputtering resistance, and, therefore, longer cathode lifetimes. They are compatible with conventional silicon substrates, allowing straightforward device integration with excitation circuitry, amplifiers, and signal conditioners. They are superior alternatives to diamond and other carbon-based thin films, being easier to deposit and pattern, and more resistant to attack by oxygen and water vapor. Some of the critical electronic properties will be optimized by post-growth modification techniques. Ion implantation and irradiation with x-rays and excimer lasers will be used to lower the threshold voltage, without detrimental changes to emission stability.We will also model the electron emission process in these films. Our model will cover electron injection from the substrate to the emitting layer, electron transport through the material, and finally emission into the vacuum. Naturally, we expect the modeling and characterization phases of the study to feedback to each other, ultimately resulting in an effective tool for device design.The final stage of the project will be development of a nitride-based pressure sensor. In contrast to current technologies, these microsensors should allow precise, accurate and reproducible pressure measurements over many decades of pressure. They also have the potential for integration in corrosive and high temperature environments. Finally, the drive and sensing electronics, which could be integrated on the same chip, can be significantly simpler than what is currently needed by conventional capacitive and piezoelectric sensors.