利用微機電技術設計與製造微波開關元件

Abstract

本論文將著重在改善微波開關元件，利用微機電技術而能建構在矽晶片上，我們設計了新的製程，成功的實現利用微機電技術以製造出微波開關元件，新的製程對於各層膜間的不平整和浮板在壓力的影響下的翹曲問題都有改善，整個結構都是利用鋁這個材料，且低於攝氏300度，所以，可以做在製程的後段，甚至可以做在化合物半導體上。 我們以相同的製造過程來製造出兩種類型微機電微波開關元件，包含有平行式和連續式以相互比較，電容吸引和獨立支撐臂是平行式和連續式的代表結構，他們在最近的微波開關領域有長足的發展，而且扮演著不同的吃重角色。我們的微波開關元件是做在微帶線上的，但是，經由設計，可以輕易的轉換到其他電路設計上（像是共平面波導式）。 微波開關元件，基本上是用來改變無線電波或是微波信號，但是，他們也可以應用在微波相轉換電路上，還有許多其他種類的應用。且由於他們具有許多的優點又適合更高的頻段，所以，我們可以用來取代傳統的正-本-負(p-i-n)二極體或是場效二極體。

The thesis is focused on the exploration of how to improve the structure of RF switch devices on silicon structure by MEMS technology. A new process was designed to fabricate these MEMS switches. This process improves the sticking effect and stress on membrane. The whole structure was constructed with aluminum under 300oC, and we can fabrication it on back end process, even could fabricate on compound substrate. We will compare to two types of RF MEMS Switches (parallel and series) in the same process. Capacitive and Cantilever are the stand type for parallel and series types. They have promoted exciting advancements in the field of microwave switching recently and play different role in MMIC. Our structure of RF MEMS Switch is fabricated at microstrip on silicon wafer, but we can easily design to fabricate at different kind of electric circuit design (like CPW). These switches can be used to change RF or microwave signal basically. But they can also used to RF signal phase shifter circuit and many other kinds of applications. RF MEMS switches will be used to replace traditional p-i-n diode or FET devices by their good characteristics at high frequency.