Laser Micromachining of Silicon: A New Technology for Fabricating Tera Hertz Imaging Arrays

在设计低噪声、高效率、外差接收器和亚毫米波长本机振荡器时遇到的主要障碍之一是波导结构的质量和成本。在波长小于400微米的情况下，使用标准加工技术制造矩形波导结构、馈电喇叭和反短路变得极其困难。我们使用了一种新的激光铣削技术来制造高质量的太赫兹波导元件和馈电喇叭。一旦金属化，这种结构就具有标准波导组件的特性。与使用硅湿法刻蚀技术制作的波导组件不同，激光刻蚀的组件可以具有几乎任何横截面，从矩形到圆形。在计算机控制下，整个波导结构(包括波纹馈电喇叭！)在几个小时内就可以将亚毫米波混频器或倍增器制造成微米级公差。激光刻蚀允许将成功的波导倍增器和混频器设计直接调整到太赫兹频率。由于整个过程是由计算机控制的，因此制造亚毫米波导元件的成本大大降低。利用这种新的激光刻蚀工艺，可以很容易地构造出高性能的太赫兹频率的波导阵接收器。我们申请资金在亚利桑那大学建造一个激光微机械系统。该系统将用于继续我们将这一工艺应用于亚毫米波成像系统的研究。*

9800260WalkerOne of the main obstacles encountered in designing low noise, high efficiency, heterodyne receivers and local oscillator sources at submillimeter wavelengths is the quality and cost of waveguide structures. At wavelengths shorter than 400 micrometers, rectangular waveguide structures, feedhorns, and backshorts become extremely difficult to fabricate using standard machining techniques. We have used a new laser milling technique to fabricate high quality, THz waveguide components and feedhorns. Once metallized, the structures have the properties of standard waveguide components. Unlike waveguide components made using silicon wet-etching techniques, laser-etched components can have almost any cross section, from rectangular to circular. Under computer control, the entire waveguide structure (including the corrugated feedhorn!) of a submillimeter-wave mixer or multiplier can be fabricated to micrometer tolerances in a few hours. Laser etching permits the direct scaling of successful waveguide multiplier and mixer designs to THz frequencies. Since the entire process is computer controlled, the cost of fabricating submillimeter waveguide components is significantly reduced. With this new laser etching process, the construction of high performance waveguide array receivers at THz frequencies becomes tractable. We request funds to construct a laser micromachining system at the University of Arizona. The system will be used to continue our research into the application of this process to the fabrication of submillimeter-wave imaging systems.***