利用離子佈植/電漿植入於矽化鎳 N+/P 接面與複晶矽鍺閘極之研究

Abstract

在本論文中，我們主要探討矽化鎳的材料特性應用在元件上，熱穩定性是一大缺點，因此我們使用鈦和鋯金屬來改善矽化鎳的熱穩定性。在之前的研究，對P+/N接面而言，鋯金屬覆蓋於矽化鎳上對片電阻有明顯改善，為了使鋯金屬覆蓋層能運用在CMOS製程上，我們探討它對N+/P接面的影響。N+/P接面形成藉由砷離子佈植，含鋯的多層結構對接面的漏電流有些微的改善。但對藉由磷離子佈植形成的接面，含鈦的多層結構會大幅的改善接面的電性。此外，我們也探討利用PH3電漿植入方法形成淺接面對矽化鎳的影響。對PH3電漿植入的阻值，我們可以得到最佳條件。在鈦和鋯多層結構金屬應用於矽化鎳研究上，我們發現含鋯的多層結構能有效改善矽化鎳造成的漏電流，這是由於鋯金屬可以抑制矽化鎳結塊的發生。在第四章的實驗結果發現，氮離子的植入能有效改善矽化鍺的熱穩定性,歸因於氮離子的植入可抑制結塊現象。

In this thesis, we have studied the material properties of nickel silicide and the application for devices. Thermal stability of nickel silicide is poor. Hence, we use Titanium and Zirconium capping layers to improve the thermal stability of nickel silicide. It had been reported that the sheet resistance of p+/n junctions could be improved with Zr-capped nickel silicide. In order to apply Zr-capping layer in CMOS process, we investigated the influence of nickel silicide with Zr-capping layer on n+/p junctions. The n+/p junctions were implanted by arsenic in this experiment. It is observed the Zr-capped nickel silicide exhibit slight improvement in junction leakage current. On the contrary, Ti-capped nickel silicide had been shown to be extremely effective in improving the electrical characteristics of phosphorous implanted n+/p junctions. We also investigated the effects of nickel silicide on PH3 plasma immersed shallow junction. Then the optimum sheet resistance could be achieved for PH3 plasma immersion. Furthermore, it is observed the junction leakage current can be effectively reduced by using Zr-capped NiSi due to prohibited agglomeration in Zr capping. Besides, we also studied Ni germano-silicide on poly-SiGe with N2+ implantation. The obtained results suggest that nitrogen implantation can enhance thermal stability of nickel germano-silicide. That is because the N2+ implanted could suppress the agglomeration of nickel silicide.