氧對鎳誘導非晶矽結晶的影響

Abstract

本篇論文研究金屬鎳誘發非晶矽測向結晶時氧的影響。在退火過程中，使用含氧的退火氣氛並不會對金屬誘發測向結晶的長度和成長速率有影響。而鎳薄膜中若有氧的存在，也不會對其金屬誘發測向結晶的速率有所影響。然而，含氧鎳薄膜卻會阻礙多晶矽的結晶作用大約四小時。這是因為含氧鎳薄膜需要一段醞核時期，在這醞核時期中，含氧鎳薄膜還原成足夠的鎳金屬，以便於進行接下來的非晶矽結晶步驟。 除此之外，金屬鎳與非晶矽間介面若有原生氧化矽(native oxide)的殘留，則更進一步的會影響醞核時期，使之增加到六小時，並且金屬誘發測向結晶的速率也會減少到2.2 μm/hr，而沒有原生氧化層殘留試片的結晶速率則為4.1 μm/hr。

Effects of oxygen on the growth of metal (Ni) induced lateral crystallization (MILC) of amorphous silicon have been investigated. It is found that the oxygen in the annealing ambient did not degrade the MILC length or growth rate. The oxygen existence in Ni film does not degrade the MILC growth rate either. However, it retards the nucleation of poly-Si for about 4 h. This is because that NiOx needed an incubation period to be reduced to nickel metal for the subsequent mediated crystallization of a-Si process. In addition, the native oxide contaminated in interface between Ni and a-Si has been studied. It would impede the NiO reaction with a-Si and retards the nucleation of poly-Si for about 6 hr. The MILC rate that is 4.1 μm/hr without native oxide in interface is degraded by the native oxide for about 2.2 μm/hr in comparison.