矽基超寬頻紅外光譜偵測器之研究

Abstract

二十一世紀是高科技產業急速起飛的一個世紀，在我們的生活周遭充斥著高科技下的產物，諸如手機及各式穿戴裝置等，這些高科技產品的出現帶給人們極大的便利，但同時人們生活的環境也因科技工業的蓬勃發展逐漸惡化，如同時常佔據新聞版面的空污、汙水排放及食安等問題，也因為這樣人們越來越注重生活的安全、健康與品質。為了因應這樣的環境變化，即時偵測便開始顯得重要，而現今的偵測設備多半有體積過大、昂貴或是精準度不高等問題，因此本論文意在開發一種紅外光偵測器，有利於隨身攜帶、偵測種類多元且精準度高之微型光譜儀系統。 本論文以寬頻紅外波段偵測做為目的，並以矽基金屬半導體光二極體作為主體進行偵測，以不同的基板類型及金半接觸電極並搭配不同的入射方式進行嘗試，成功研製出電性穩定且於1550奈米波段下有極高光電響應之近紅外光偵測元件。接著，我們引入局域表面電漿共振的現象，利用正倒立金字塔具漸變式腔體長度的方式誘發寬頻的共振，並利用COMSOL模擬軟體進行模擬，而後成功利用氫氧化鉀蝕刻的方式，製作出週期為4至12微米不等之倒立金字塔陣列結構及週期4至6微米微米不等之正立金字塔陣列結構。最後將金半光二極體與正倒立金字塔進行結合，藉由局域表面電共振強化元件的光電響應及偵測範圍，在1.55微米光通訊波段以週期4微米之正立金字塔陣列元件得到1878.9 nA/mW的響應強度，而在4.16微米波段部分，利用金字塔局限的效應，藉由光場在金字塔金屬腔壁上共振並產生熱能以進行偵測，並於週期6微米之正立金字塔陣列元件得到最大電流變化率4.609×10-1 nA/ms，成功研製出超寬頻之矽基金半光偵測器。

With high-tech industry taking off rapidly in 21st century, we are surrounded by high-tech products such as mobile phones and various wearable devices which bring a lot of convenience to the people. However, with the development of technology industry flourishes, the environment is getting worse. Therefore, people pay more attention to the safety, health and the quality of living. In order to solve the changes in environmental, instant detection has become vary important. Nonetheless, most of the detection equipment has some problems, like a large volume, expensive or not accurate. In this thesis, a mid-infrared detector is demonstrated for the concept of the miniature spectrometer system which is portable, multi-detection high precision. In our study, the Si-based metal-semiconductor diode to detect the infrared light source is studied. Through the metal selection, fabrication process and measurement method, the performance of the device is enhanced. The photodetector, which has stable IV characteristics and high sensitivity at 1550 nm laser signal, is developed. Then, the phenomenon of localized surface plasmon resonance (LSPR) is explored through the upright/inverted pyramid to induce the broadband resonance and the simulation software (COMSOL) is used to simulate the distribution of electromagnetic field. Afterwards, the periodic upright/inverted pyramid array structures are successfully manufactured by using a potassium hydroxide etching method. Finally, the metal-semiconductor photodiode and the periodic upright/inverted pyramid array structure are combined to achieve the broadband infrared detectors by the phenomenon of localized surface plasmon resonance. The results show that the response of 4 µm UPA device can reach 1878.9 nA/mW at 1550 nm laser signal and the current variation rate of 6 µm UPA device can reach 4.609×10-1 nA/ms at 4.16 µm light source. In summary, the broadband infrared detector is successfully developed.