應用碳化鈦導電薄膜於微機電碰撞開關之可行性研究

Abstract

本論文研究重點在探討將碳化鈦鍍膜應用於微機電碰撞開關上之可行性，目標在增加碰撞開關使用壽命，並防止元件在常溫下氧化。 首先針對碳化鈦進行基本性質研究後發現，在30奈米相同厚度下碳化鈦鍍膜耐磨耗能力是鎳金屬鍍膜的2倍，硬度是鎳金屬鍍膜的3倍。在抗氧化、導電率等方面碳化鈦鍍膜使用環境溫度應低於200℃，超過300℃時碳化鈦薄膜則完全氧化，且當隨著碳化鈦薄膜厚度增加，薄膜受溫度變化造成的電阻值波動越不明顯。 在此進一步設計一測試結構，並分別濺鍍碳化鈦與鎳金屬薄膜，進行碰撞磨耗及氧化保護實驗，發現濺鍍30奈米厚度的碳化鈦薄膜可比濺鍍鎳金屬薄膜的元件碰撞壽命提高7倍以上，經過100℃加熱後濺鍍碳化鈦薄膜比濺鍍鎳金屬薄膜的元件氧化時間延長2倍以上，且碳化鈦薄膜厚度增加，可進一步延長氧化時間。

This study, we present an inertial switch which employing titanium carbide (TiC) protective thin film to increase abrasion resistance, and simultaneously, autoxidation. Our objective is to enhance the life cycle of inertial switch. Both 30 nanometer film thickness, TiC has better performance than Nickel in Microhardness and Microscratch tests. TiC coating shows Vickers hardness values increased by 300% than Nickel coating. And the volume of material removed, TiC coatings is 50% lower than Nickel coating. The isothermal oxidation and conductivity of TiC film was carried out at low temperature of 100-500℃ at atmospheric. Results shows that the TiC film at temperature higher than 300℃ will completely oxidized, temperature lower than 200℃ the conductivity varies unobvious. We also found that the resistance fluctuates according to the temperature change decrease when film thickness rising. Design an MEMs switch for impact fatigue test and oxidation protect test. Impact fatigue test shows, both 30 nanometer thickness, coating TiC can improve the switch life cycle 700% than coating Nickel. And oxidation protect test shows, both 30 nanometer thickness, coating TiC can prolong oxidation time over 200% than coating Nickel.