| 摘要: | 此論文研究主題主要是針對離子佈植對於鎳合金矽化物之影響，其中，因也許多文獻提到含鉑的鎳合金矽化物形成於矽基板上可以改善熱穩定性的特點，因此，在本研究當中的兩個子題皆以此為對照組。在第一個子題，首先先針對含鈦的鎳合金矽化物形成於預離子佈植之矽基板(PAI-Si)上之生成反應進行研究。從實驗中，發現含鈦的鎳合金矽化物形成於矽基板上，因為鈦猶如一中間層，會使鎳不容易擴散，而提早二矽化鎳(NiSi2)的生成，且退火溫度越高，根據熱力學定理，則二矽化鎳會變為一平整面，藉此改善其電性。此外，含鈦的鎳合金矽化物形成於預離子佈植之矽基板上，可發現經由低溫退火後也會有二矽化鎳相，其原因為預離子佈植之基板，表面會變為非晶質，而降低二矽化鎳成核所需的能量，另一方面，非晶質的矽也會讓鎳的擴散變快，因此，具有低電阻的矽化鎳(NiSi)生成，但再經由更高溫的退火，金屬鎳反應完之後，則二矽化鎳又開始生成，但因其非晶質矽與結晶矽之介面含有離子佈植的氙，而影響二矽化鎳的成長，因此其介面較為不平整，因此使用添加鈦的鎳合金在預離子佈植的矽基板上形成鎳合金矽化物，不僅使低電阻的矽化鎳的製程溫度變大，也可以進一步改善蕭基能障高度。 在第二個子題部分，在鎳-鐿矽化物形成於矽基板之探討的部分。從結果得知，利用鐿的添加，不僅可以生成含有低功函數的鎳-鐿矽化物，也進一步改善因為在鉑-矽系統中，NiSi薄膜經由高溫退火之後會變為島嶼狀的熱穩定性之缺點，而提升元件的可靠性。另一方面，利用碳的離子佈植製程，而在矽化過程中，因為碳不溶於矽化物，而在矽化物與矽基板之間的累積，以改善薄膜的熱穩定性，因此若能善加利用含鐿的鎳矽化物及碳離子佈植兩者所擁有的優點，定能有效改善矽化物在元件中的可靠度。 The research topics that effect of ion implantation on nickel alloy silicide. Reportedly, the thermal stability of Ni silicides was improved by the introduction of Pt atom. For comparison, the Ni-Pt /Si samples were also prepared at the same conditions. Frist, one of this study investigates the formation of Ni-Ti silicide on preamorphization implanted Si ( PAI-Si). The system of Ni-Ti silicide formed on the Si substrate, the NiSi2 was the only silicide phase. This study proposes a mechanism that Ti-just interface, effectively hindering the Ni atom diffuse into Si substrate. Furthermore, according to the theorems of thermodynamics, a flat (100) interface was formed at high temperature. In addition, the Ni-Ti silicide formed on PAI-Si substrate, the NiSi2 was formed at low temperature. The NiSi2 phase formed completely through the amorphous silicon and stopped at the crystalline substrate. It did not penetrate further due to the absence of a driving force, which, in the case of reaction with amorphous silicon, is provided by an excess free. However, the rough interfaces of amorphous silicon and crystalline silicon with ion implantation of Xe, which will affect the growth of nickel disilicide. For the Ni-Ti silicide formed on PAI-Si substrate, not only larger the low-resistance nickel silicide process temperature but also improving the Schottky barrier height. On the other hand, the formation of Ni-Yb alloy silicides on Si substrate has been systematically investigated in this study. The presence of Yb atoms can form with a low work function of Ni-Yb silicides and suppress the agglomeration of silicide films at high temperature. In addition, the process of carbon ion implantation in the Ni-Yb alloy films, the carbon is not soluble in the silicide. It is likely that carbon segregates to the silicide/ Si interfaces to improve the thermal stability of the film. If we can combine the process of Ni-Yb alloy silicides and carbon ion implantation we will be able to effectively improve the silicide in the component reliability. |
