微小機電梳狀結構致動器之研製

Abstract

本文主旨在研製微小機電梳狀結構致動器，其目的在利用電壓來控制致動 器微米級的位移。此制動器的位移量與兩個電極（一個為固定，另一各式 可移動的）的電場耦合效率、複晶矽的磷摻雜濃度及低應力薄膜的控制有 關。為增加電場的耦合，使用非等向性的活性離子蝕刻，獲得垂直的複晶 矽剖面，並且，由增加磷的摻雜濃度可加強電場強度，以增加兩電極的吸 引力。另外，用1050℃的高溫度退火以降低薄膜應力，防止在移去犧牲層 後薄膜與基板的吸附效應。結果，我們證實此種致動器的研製，有幾微米 的移動。 This thesis presents the comb actuators in surface micromachining. The goal ofthis thesis is to establish a foundation for electrostatically exciting and sensing suspended transducer elements based on comb-drive structure, with the viewpoint on potential resonant sensor and actuator applications. Anisotropic etching with RIE process is used to improve electric field coupling. Besides, high phosphorus-doped concentration can offer more free electron to build up high electric attractive force between two electrodes. To avoid sticking problem, the low stress of thin film is needed. LPCVD polysilicon annealed at 1050℃ was adopted for the reduction of film stress.