An alternative methodology in Schottky diode physics
An alternative methodology in Schottky diode physics
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DOI：
10.1063/1.4922974
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发表时间：
2015-06-28
影响因子：
3.2
通讯作者：
Dawson, P.
中科院分区：
文献类型：
--
作者：
Mitra, J.;Feng, L.;Dawson, P.
自1938年肖特基的原始工作以来，肖特基结二极管的制造和电气特性已经被广泛研究了四分之三个世纪。这项研究打破了这种研究的高度标准化制度，并提供了一种替代方法，促进了灵巧肖特基结在化学和热感测等领域的新颖、更有效的应用。与标准肖特基二极管配置的核心区别是，金属电极的电阻与底层半导体相当或更高。此外，通过记录器件的四探针电阻-温度（R-D-T）特性来完成完整的电特性，其中电源和传感仅通过金属电极完成，而不是直接通过半导体。重要的是，这导致探测一个名义上的无偏结，同时消除了对半导体欧姆接触的需要。特征R-D-T图分别显示了低温和高温下两个不同的高（金属）和低（半导体）电阻区域，它们由一个宽度为DT的交叉区域连接，在这个交叉区域内存在较大的负温度电阻系数。R-D-T特性对肖特基势垒高度高度敏感；因此，在固定温度下，R-D对势垒高度的微小变化有明显的响应，例如由界面上化学物质（例如H-2）的吸收引起的势垒高度变化。建立了一个理论模型来模拟R-D-T数据，并应用于具有一定金属电极电阻范围的Pd/p-Si和Pt/p-Si肖特基二极管。分析给出了接近完美的拟合实验R-D-T特性，得到了作为拟合参数的结特性。建模不仅有助于阐明底层物理，而且有助于理解所讨论的应用所必需的参数空间。虽然主要的应用仅限于一个相对狭窄的范围（DT）为给定类型的二极管，替代方法是普遍适用于所有金属半导体组合形成肖特基触点。(C) 2015 AIP出版有限责任公司
The fabrication and electrical characterization of Schottky junction diodes have been extensively researched for three-quarters of a century since the original work of Schottky in 1938. This study breaks from the highly standardized regime of such research and provides an alternative methodology that prompts novel, more efficient applications of the adroit Schottky junction in areas such as chemical and thermal sensing. The core departure from standard Schottky diode configuration is that the metal electrode is of comparable or higher resistance than the underlying semiconductor. Further, complete electrical characterization is accomplished through recording four-probe resistance-temperature (R-D-T) characteristics of the device, where electrical sourcing and sensing is done only via the metal electrode and not directly through the semiconductor. Importantly, this results in probing a nominally unbiased junction while eliminating the need for an Ohmic contact to the semiconductor. The characteristic R-D-T plot shows two distinct regions of high (metal) and low (semiconductor) resistances at low and high temperatures, respectively, connected by a crossover region of width, DT, within which there is a large negative temperature coefficient of resistance. The R-D-T characteristic is highly sensitive to the Schottky barrier height; consequently, at a fixed temperature, R-D responds appreciably to small changes in barrier height such as that induced by absorption of a chemical species (e.g., H-2) at the interface. A theoretical model is developed to simulate the R-D-T data and applied to Pd/p-Si and Pt/p-Si Schottky diodes with a range of metal electrode resistance. The analysis gives near-perfect fits to the experimental R-D-T characteristics, yielding the junction properties as fit parameters. The modelling not only helps elucidate the underlying physics but also helps to comprehend the parameter space essential for the discussed applications. Although the primary regime of application is limited to a relatively narrow range (DT) for a given type of diode, the alternative methodology is of universal applicability to all metal-semiconductor combinations forming Schottky contacts. (C) 2015 AIP Publishing LLC.