ZnO MESFETs for application to Intelligent Windows

这项研究的中心目标是在玻璃窗中制造电子电路，用于视觉显示、监控和控制目的：“透明电子”。电路由一种非常薄的类似半导体的材料(氧化锌：氧化锌)和薄的金属触点组成。这种材料如此之薄(10‘S纳米)，以至于大多数光线都能直接穿透。因此，“智能”可以被构建到窗户中。所使用的材料还提供了光学上的优势，即“低发射率”；其折射率有助于增强对太阳能的捕获，并减少建筑物的热损失。在玻璃涂层中引入电子功能的附加值可以为建筑物、汽车和飞机打开新一代玻璃窗；特别是用于平视显示器。最后一种应用目前使用的是含有铟的薄膜。这是一种非常昂贵的材料，所以用氧化锌取代它将降低成本，从而打开了这类产品的可获得性。氧化锌也是低毒的。我们将使用的器件称为金属半导体场效应晶体管(MESFET)。之所以选择这些器件，是因为它们非常简单，很容易制造。它们的工作电压也低于计算机和电话等中常见的金属氧化物场效应晶体管(MOSFET)。MESFET的使用避免了开发技术上非常具有挑战性的栅氧化物技术的需要。缺点是数字电路需要更复杂，因此需要占用更多空间。然而，电路的占地面积没有硅基芯片那么关键，因为电子产品是在大面积的面板上。然后，该项目涉及MESFET制造工艺的建立、预期电路的器件设计以及基本电路块和门阵列的设计和实现。

The central aim of the research is to produce electronic circuits into glass windows for visual display, monitoring and control purposes: 'transparent electronics'. The circuits are made from a very thin semiconductor-like material (ZnO: zinc oxide) and thin metal contacts. The materials are so thin (10's nm) that most of the light passes straight through. Thus 'intelligence' can be built into the window. The material used also offers optical advantages in that is 'low emissivity'; its refractive index serves to enhance the capture of solar energy and reduces the heat loss from the building. The added-value of introducing electronics capability into the glass coatings can open up a new generation of glass windows in buildings, cars and aeroplanes; especially for 'heads-up' displays. The last application is currently available using films containing indium. This is a very expensive material so its replacement with ZnO will bring down the cost and so open up the availabilty of such products. ZnO also has low-toxicity. The devices we will use are called metal-semiconductor field effect transistor (MESFET). These devices are chosen because they are very simple and easy to fabricate. They also operate at lower voltages than the more commonly used metal-oxide field effect transistor (MOSFET), which is found in computers and phones etc. The use of MESFETs avoids the need to develop a gate oxide technology which is very challenging technologically. The downside is that the digital circuits need to more complicated and so take up more space. However, the footprint of the circuits is less critical that for Si based chips, as the electronics is on large area panels. The project is then concerned with the establishment of a MESFET fabrication process, device design for the intended circuitry and finally design and realisation of basic circuit blocks and gate arrays.