微米尺寸金屬盒子的製備與加熱頻譜量測

Abstract

在電燈被發明那一刻起，照明就成為人類生活中不可或缺的一部份，人類的發展也從此邁向新的紀元，隨著科技不斷的發展燈泡的壽命越來越長，同時也越來越亮，不過卻改變不了一個事實，那就是在燈泡發光的同時，大部分的能量是被轉換成熱能消耗掉了。傳統燈具，採用專用鎢絲燈為光源，壽命與耗能已漸不符合能源效益，為了使能量運用的效率提高，我們思考一個可以增強傳統黑體輻射特定波長的微結構，名為『金屬盒子』。 我們在矽晶片上設計並製作由金屬包覆介電質的金屬盒子結構，利用電磁學中空腔共振的原理，我們可以計算出元件增益的訊號。允許在共振腔內的電磁波稱為共振模態，而相應的波長稱為共振波長。 我們嘗試了壓印技術來製作元件，包括以熱壓印及以雷射輔助微米壓印，整個過程包括了曝光、顯影、蝕刻、蒸鍍等標準半導體製程。但最後並無法正確的製作出金屬盒子結構。故我們採用微影製程的方式完成金屬盒子的結構 為了使模擬更容易，我們也設計結構簡單的金屬盒子，尺寸包括1μm、2μm、3μm見方，高度分別為150nm、200nm。我們以這樣的尺寸做模擬所得的結果，初步印證了金屬盒子的可行性 我們模擬藉由改變元件的尺寸，可以調變加熱頻譜的增益訊號，在紅外光波段的實驗與模擬結果也能吻合，以這樣的構想，期望在可見光波段也能有增益的效果，這樣將可因應各種照明或光學應用上的需要。

Since light bulb was invented, lighting has become an essential part of the human civilization advancing towards a new century. Accompany with the unceasing development and advancement of science and technology, light-bulb’s life-span is extended and its brightness is increases. However, the great part of energy from the light bulb is heat. Traditional lights, which use tungsten lamp as the source of light, are not energy efficient in terms of life span and energy consumption. To make efficient use of energy for light, we investigate a microstructure to enhance specific signal of thermal radiation spectrum, named “metallic box”. We design and fabricate metallic box structures with dielectric cube wrapped by metal on the silicon wafer. Applying the theorem of cavity resonance through Maxwell’s equations and boundary conditions, we can calculate the specific spectrum of the component. The allowable EM waves are called resonance modes and the corresponding wavelengths are called resonance wavelengths. We had tried the imprint technology to fabricate the metallic box, including hot embossing and Laser pulse assisted imprint lithography, the whole process made by standard VLSI process such as exposure, development, dry etch, and evaporation. We could not fabricate the metallic box accurately by the imprint technology. So we use the conventional lithography technology to accomplish the metallic box. Our metallic boxes have simple resonant cavity structure for a complete simulation for verification of our design. The dimension of the dielectric cubes is designed to be 1μm、2μm、3μm in square, and their height is 150nm or 200nm. After simulating the metallic box with such dimensions, we prove the feasibility of metallic box preliminarily We can vary the dimension of metallic box to change the spectrum of thermal radiation. In infrared band, we can approximately match the experiment and the simulation. It is expected that we can enhance the signal in visible light band for future illumination and optical applications using this concept.