Resistive-metal-electrode Schottky diodes for temperature sensing

用于温度传感的电阻金属电极肖特基二极管

• 批准号: EP/G000433/1
• 负责人: Paul Dawson
• 金额: $ 10.99万
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG000433%2F1
• 关键词: Resistive; metal; electrode; Schottky; diodes

Schottky diodes, which comprise a metal electrode deposited on a clean semiconductor surface, are perhaps the simplest of all semiconductor devices. There is an inbuilt potential barrier which means that it is much easier to pass current in one direction through the device than in the opposite direction. In other words the device has a rectifying action and from that it derives its great utility. This assumes that the current is driven across the barrier i.e. one of the electrical contacts to the outside world is attached to the metal electrode and the other to the semiconductor substrate. Here we consider what happens if the resistance of the metal electrode itself (let's call it Rm) is measured while the temperature of the device is changed. What we have noticed is that as the temperature increases the apparent value of Rm decreases quite substantially over a limited temperature interval of ~50K. In preliminary work on PtSi/p-Si diodes (platinum silicide or PtSi is a type of metal and p-Si is 'doped' silicon in which the majority current carriers are holes, rather than electrons) a factor of up to 5 drop in Rm has been observed in the temperature range 100-150K. The reason is that at low temperature (< 100K) the current carriers in the metal are confined to the metal electrode by the built-in potential barrier. However, as the temperature increases the current carriers (electrons in the metal and holes in the semiconductor) can progressively start to cross the barrier between the two - what this means is that the semiconductor opens up as a parallel current carrying channel and so Rm decreases. In fact Rm is now really the resistance of the semiconductor wafer in parallel with the metal electrode. There is a proviso, which is that the metal electrode should have a higher resistance than the semiconducting substrate. This is kind of the wrong way round but can be arranged if the metal electrode is very thin (<10 nm); in fact Rm can be very much greater than the resistance of the semiconductor substrate if it is also long and narrow (width 1 micron or less). Since this is not normally the case and electrical measurements are normally taken across the barrier, there appears to have been something of a blind-spot regarding this effect in semiconductor device research. This preliminary project aims to exploit and enhance the effect so that the observed change in resistance, Rm, is a factor of 100 or 1000 or perhaps even more.In effect the device will be an extremely sensitive temperature sensor and that is the immediate application that is envisaged. Temperature sensors form a crucial component in various control circuits and are used widely in the PC, automotive and communications sectors. The temperature range in which the resistance change occurs depends on the height of the potential barrier which in turn depends on the specific metal-semiconductor combination. The good news is that the range of such combinations and of corresponding potential barriers is such that the temperature sensitive window can probably be designed to fall anywhere in the range from 50K to 500K (or let's say approximately -225oC to +225oC). Longer term, we think that such devices could be also adapted to highly sensitive gas sensing.

肖特基二极管，包括沉积在干净的半导体表面上的金属电极，可能是所有半导体器件中最简单的。有一个内置的势垒，这意味着它是更容易让电流在一个方向通过设备比在相反的方向。换句话说，这个装置有一种矫正作用，并由此获得了巨大的效用。这假设电流被驱动穿过阻挡层，即，到外部世界的电接触中的一个被附接到金属电极，而另一个被附接到半导体衬底。在这里，我们考虑如果在设备温度变化的同时测量金属电极本身的电阻（我们称之为Rm）会发生什么。我们注意到，随着温度的升高，在~ 50 K的有限温度区间内，Rm的表观值显著降低。在PtSi/p-Si二极管的初步工作中（硅化铂或PtSi是一种金属，p-Si是“掺杂”硅，其中大多数载流子是空穴，而不是电子），在温度范围内观察到Rm下降高达5倍100- 150 K。这是因为在低温下（<100 K），金属中的载流子被内建势垒限制在金属电极上。然而，随着温度的升高，载流子（金属中的电子和半导体中的空穴）可以逐渐开始越过两者之间的势垒-这意味着半导体作为平行的载流通道打开，因此Rm减小。实际上，Rm现在实际上是与金属电极并联的半导体晶片的电阻。有一个限制条件，即金属电极应具有比半导体衬底更高的电阻。这是一种错误的方式，但如果金属电极非常薄（<10 nm），则可以设置;事实上，如果半导体衬底也很长且窄（宽度为1微米或更小），则Rm可以比半导体衬底的电阻大得多。由于通常情况下情况并非如此，并且通常在屏障上进行电气测量，因此在半导体器件研究中关于这种效应似乎存在盲点。该初步项目旨在利用和增强这种效应，使观察到的电阻变化Rm为100或1000甚至更大。实际上，该器件将是一个非常灵敏的温度传感器，这是设想的直接应用。温度传感器是各种控制电路中的关键部件，广泛应用于PC、汽车和通信领域。发生电阻变化的温度范围取决于势垒的高度，而势垒的高度又取决于特定的金属-半导体组合。好消息是，这样的组合和相应的势垒的范围是这样的，温度敏感窗口可能被设计成落在50 K到500 K（或者说大约-225 ° C到+225 ° C）范围内的任何地方。从长远来看，我们认为这种设备也可以适用于高灵敏度的气体传感。

项目成果

The electrical characterization and response to hydrogen of Schottky diodes with a resistive metal electrode-rectifying an oversight in Schottky diode investigation

具有电阻金属电极的肖特基二极管的电气特性和对氢的响应——纠正肖特基二极管研究中的疏忽

• DOI: 10.1088/0022-3727/44/12/125101
• 发表时间: 2011
• 期刊: Applied Physics
• 作者: Dawson P

An alternative methodology in Schottky diode physics

• DOI: 10.1063/1.4922974
• 发表时间: 2015-06-28
• 期刊: JOURNAL OF APPLIED PHYSICS
• 影响因子: 3.2
• 作者: Mitra, J.;Feng, L.;Dawson, P.
• 通讯作者: Dawson, P.

Unusual photoresponse of indium doped ZnO/organic thin film heterojunction

• DOI: 10.1063/1.4704655
• 发表时间: 2012-04
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: S. Vempati;Saraswathi Chirakkara;J. Mitra;P. Dawson;K. Nanda;S. .. Krupanidhi

High sensitivity (1 ppm) hydrogen detection using an unconventional Pd/n-InP Schottky device.

使用非常规 Pd/n-InP 肖特基器件进行高灵敏度 (1 ppm) 氢检测。

• DOI: 10.1088/0953-8984/23/42/422201
• 发表时间: 2011
• 期刊: an Institute of Physics journal
• 作者: Feng L