摘要:在奈米科技發展蓬勃的今日,許多科技產業都朝向奈米級尺寸的研究,而由於檢測技術乃是各項技術開發時之先行技術,因此檢測技術絕對是開發奈米技術中極為重要的一環。近場顯微技術是一突破光學繞射極限,以近場的方式獲取高解晰度的顯微技術,由於相關製作技術的突破以及相關光學現象的深入了解,乃使近場光學顯微技術的應用越來越廣泛。在沒有遠場繞射極限的限制下,此類技術可以觀測更小尺寸等級的待測物,再加上不須對試件做特殊表面處理、具有非接觸式的量測、不會傷害待測物等優點,此類技術之應用範疇日漸寬廣。近年來,由於奈米科技研究更朝向多元化的發展,因此除了待測物的表面輪廓與光學性質的瞭解日趨重要外,其動態資訊更是各項系統研發中極為重要的指標,因此如何建構一套奈米級多功檢測設備實屬迫切需要。有鑑於此,本計畫審視現行全球所發展的近場光學量測系統,在現有的應用近場光學架構中,提出研發具有奈米精度之動態檢測光學系統的計畫目標。
因此本計畫的目標在量測近場光學下之待測物的動態資料,藉由結合創新干涉技術與掃描式近場光學顯微鏡(Near-field Scanning optical microscopy, NSOM)來建構創
Abstract: With the rapid development of nanotechnology, the number of scientific industries focused their research on nanotechnology are increasing rapidly. As nano-metrology is typically the pre-requisite for developing various nanotechnologies, it played an ever more important role in all nanotechnology research efforts. The near-field microscopy, for example, is a kind of imaging technology with spatial resolution unlimited by the traditional optical diffraction limit. Due to better understanding of the near-field optic theory and the improvement of fabrication techniques in recent years, the applications of near-field microscopy have became more popular. One advantage of near-field microscopy is that it can observe sub-wavelength features without any sample surface preparation process a priori. Besides, it will not disturb or damage the sample due to its non-contact nature. Recently, the diverse development of nanotechnology demands the research in this field focus not only on how to map topographic and optical properties with extremely high spatial resolution, but also on multi-point dynamic measurements. It is to be noted that maintaining nanometer resolution in these new developments is a must as well. In order to perform further research on nanotechnology, there is an imminent need for a metrology system that can perform both static and dynamic measurement with nano-scale resolution. Therefore, after reviewing all state-of-the-art near-field metrology systems, this proposal plans to develop a nano-metrology system that has dynamic measurement ability.
One objective of this proposal is to use the Near-field Scanning Optical Microscopy (NSOM) to understand how the nano-scale vibration of the sample will disturb the evanescent wave in the near-field regime. After developing the theory needed to understand this disturbance, we will combine this theory with the Photon Tunneling Microscopy (PTM) technique to develop a full-field, nano-scale, dynamic metrology system. Traditionally, the near-field microscopy only measures the intensity of light, and the interferometer only measure the phase information in the far-field range. However, this proposal plans to combine these two technologies to get both the phase and the amplitude information of the evanescent wave in the near-field regime. In order to achieve very high signal to noise ratio, we will study heterodyne interferometry, quadrature detection methods adopted in circular polarization interferometry and phase recovery method to get accurate phase information. Then we can calculate the displacement and velocity of the sample’s vibration. In addition, the direction ambiguity problem can be solved as well. In short, this proposal plans to initiate a three-year approach to develop the theory, design, and know-how on constructions needed to develop a metrology system prototype that can measure nano-scale vibration in the near-field regime.