Integrated Sensing Porous Silicon Integrated Sensor Arrays

传感器应该是灵敏的、选择性的、可逆的和廉价的。我们首次展示了一种基于稳定的多孔硅界面应用的高灵敏度、快速响应的电导测量设备。这种传感器在室温下以极低的偏置电压工作，现在能够检测气体HCl、NH3和NO(L.Seals等人，J.Appl。PHY.，91,2519(2002)]在10到100 ppm之间的水平(校准)。该传感器尚未优化，设计简单，响应速度快，是可逆的。它可以通过表面涂层进行选择，并可以通过测量电子设备集成到阵列中。传感器响应的关键是通过对改性的多孔硅表面进行化学金属化与硅进行低电阻接触，从而产生低于100O的接触电阻，而不是通常用多孔硅器件观察到的200kO-MO电阻。我们建议研究传感器响应随结构和界面变化的函数，并建立传感机制，以优化传感器设计，提高灵敏度、选择性和响应时间。作为提高灵敏度的一种手段，我们将研究微孔/纳米孔组合结构中表面形态对响应的影响。为了增加选择性，表面涂层和选择性膜将与传感器结合放置。或者，我们将传感器耦合到微型GC柱上作为检测器，或者在柱本身内以多阵列形式耦合。

A sensor should be sensitive, selective, reversible, and inexpensive. We have demonstrated, for the first time, a highly sensitive, rapidly responding, conductiometric device based upon the application of a stabilized porous silicon interface. This sensor, which operates at an extremely low bias voltage, at room temperature, is now able to detect gaseous HCl, NH3, and NO (L. Seals, et al, J. Appl. Phys., 91, 2519 (2002)] at a level between 10 and 100 ppm (calibrated). The sensor, which has not yet been optimized, is simple in design, operates with a rapid response and is reversible. It can be made selective with surface coatings and can be integrated into arrays with measurement electronics. The key to the sensor response is a low resistance contact made to the silicon through electroless metallization of a modified porous silicon surface, resulting in contact resistances of less than 100O's, rather than the 200 kO - MO resistances normally observed with porous silicon devices. We propose to investigate the sensor response as a function of structure and interface variation and establish the sensing mechanism in order to optimize sensor design and enhance sensitivity, selectivity, and response time. As a means of increasing sensitivity, we will study the effect of surface morphology, in a combined microporour/nanoporous structure, on response. To increase selectivity, surface coatings and selective membranes will be placed in combination with the sensor. Alternatively we will couple the sensor to a micro-GC column as a detector or in a multiple array format within the column itself.