使用表面微機電技術且CMOS相容的低溫製程下製作紅外線熱感應器

Abstract

過去幾年室溫型紅外線熱感應器已經被快速的發展成大尺寸焦面陣列，為了得到較高的解析度以及降低系統成本，與CMOS 半導體製程相容的表面微機電技術變得越來越重要，當元件的尺寸縮小，在感測層上的熱量散逸的情形變得更加嚴重。在本論文中，我們使用低溫且和CMOS半導體相容的製程實現了這個高熱絕緣的結構，在所有製程溫度皆低於400 ℃的情況下,紅外線熱感應元件底下的感測電路將不會受到損傷。我們藉由SCF的控制和經過熱處理的鋁犧牲層以及適當的溫度控制在以蒸散的乾燥方式下得到高可靠度以及高熱絕緣的紅外線熱感應元件

Over the past several years, uncooled infrared radiation (IR) detectors have been rapidly developed into large size focal plane arrays (FPA). In order to get higher resolution of thermal image and reduce the cost of the system, a CMOS compatible technology of surface micro-machining is more and more important. When the size of device scales down, the loss of heat absorbed by sensing film will become a serious problem. In this study, the high thermal isolation structure made with low temperature and CMOS compatible processes has been developed. The process temperature are all controlled below 400 ℃ which will not damage the IC below the bolometer. We used the control of SCF, an annealed process of aluminum sacrificial layer, and an appropriate control of temperature during evaporation drying to obtain the high reliability thermal isolation structure.