藉由金屬奈米粒子的表面電漿子共振特性（surface plasmon resonance, SPR）以提升矽基太陽能電池吸收效率行之有年，其中以離子束合成法（ion beam synthesis, IBS）最受矚目且被廣泛研究，但該方法卻擁有諸多缺點：（一）離子佈植所造成輻射損傷，致使材料產生難以回復的缺陷，甚至造成材料的非晶化現象；（二）植入的高濃度金屬離子將影響單晶材料的磊晶再成長（epitaxial regrowth）等。有鑑於此，本論文研究旨於開發與探討另一新穎製程，即利用氦離子佈植先行於單晶矽內部產生空腔，再行鍍上金屬薄膜並經由該等空腔對金屬原子發生化學吸附（chemisorption）、異質磊晶成長（heterogeneous epitaxial growth）效應，形成金屬奈米粒子於單晶矽內。本研究進而改變各階段的製程參數，再配合穿透式電子顯微鏡與二次離子質譜儀分析，進一步探討該製程的物理機制。研究結果顯示，室溫 40 keV 氦離子佈植於單晶矽形成空腔的臨界劑量為 9×1015 ions/cm2，且須產生空腔才具有形成金屬奈米粒子之能力；金屬原子於空腔壁上發生異質磊晶，乃因間隙金屬原子對空腔的化學吸附驅動力與形成金屬矽化物驅動力競爭下的熱力學結果；此外，空腔工程的退火溫度對於空腔的發展影響甚大，當退火溫度為 750°C 時，單晶矽內將殘留較多的穩定空腔予以形成金屬奈米粒子，當退火溫度高達 950°C 時，單晶矽內的輻射損傷因大量修復，僅殘留較少的穩定空腔，致形成較少金屬奈米粒子。

The surface plasmon resonance (SPR) effects arising from metal nanoparticles has been employed used to enhance the absorption efficiency in silicon-based solar cells for years. Ion beam synthesis is the widely-accepted method for forming metal nanoparticles, but holds some disadvantages. First, the radiation damage due to ion implantation causes lots of unrecoverable defects within material and even results in amorphization. Second, the epitaxial regrowth of single crystal material would be greatly affected by the high concentration of metal atoms implanted in material. In order to overcome the above shortcomings, this study aimed to investigate a novel process. In the process, helium ions are implanted into monocrystalline silicon to create cavities, and then induces a chemical adsorption reaction of metal atoms in cavity wall through a metal diffusion process. The results revealed that, the threshold fluence to form cavities by 40 keV helium ion implantation at room temperature is 9×1015 ions/cm2. In addition, the cavities are also the prerequisite for the formation of metal nanoparticles in silicon. The hetero-epitaxial growth of metal atoms on the cavity wall is thermodynamically allowed, which means that the heterogeneous epitaxy of metal atoms on the cavity wall is more preferable than the formation of metal silicide. Furthermore, the annealing temperature of the cavity engineering has a dramatic impact on the development of the cavities. The use of annealing of 750°C will produce more of stable cavities to form metal nanoparticles than that of 950°C.

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