| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 98 === How to control the growth of epitaxial silicide has been an issue for many years. If we can control silicide islands to grow into the shape we want, the application of silicide may have breakthrough on many fields, such as optoelectronics industry and semiconductor industry. We don’t discuss with lithography here, but talking about self-growth. Trying to control the self-growth of nickel disilicide to produce ordered structure is our main purpose.
However, we must understand the growth mechanism of nickel discilide in order to control its growth. In this thesis, we study factors which affect the growth of nickel disilicide. In previous research, it has been confirmed that the growth of nickel disilicide is govern by kinetics, and its shape distribution is related to probability. From finite element method, we have known that the height of the structure has significant influence on the relationship between strain energy of the structure and its aspect ratio. If we can change and fix the height of the islands, maybe we can change their shape distribution. Based on this reason, we try to control the height of the islands. In this thesis, we use strained-Si and SOI (silicon on insulator) as substrates to achieve our purpose. By using the thin substrates, we can force all the islands to grow into truncated-hut structure with the same height.
The experimental results have showed that the thickness of the substrate will affect the shape distribution of the islands. The islands which grew on strained-Si are different from which grew on SOI. On strained-Si, the growth of nickel disilicide may be affected by stress field, so the islands grew into irregular shape. On the other hand, the islands grew on SOI are narrower and longer than which grew on Si.
By using the thin substrates, we have achieved the goal of changing the shape distribution of nickel disilicide. Through these experimental results, we have a better understanding of how to control the growth of the islands. Although we can’t control all the islands to grow into the same shape with the same size and same orientation, we still believe that the results provided here will make contributions to the future.
|
|---|
