形成矽化鎳時在矽化鎳與矽接面處離子活化相關研究

Abstract

在先進互補式金氧半導體元件裡，當接觸尺寸縮小至奈米等級，源極及汲極的接觸電阻也會隨之增加。因此，金屬矽化物的技術應用在源極及汲極已經被開發用來同時降低接觸電阻及接面寄生電阻。在奈米金氧半場效電晶體的製造中，矽化製程是必須的，為了抑制源極及汲極的超淺接面形成所產生的短通道效應。所以，是否具有與矽基材完好介面特性的金屬矽化物，是在製造奈米尺寸的元件時重要的製程考量。在本論文中，我們主要探討離子佈植入矽化鎳再經由後續不同條件的退火製程後，所呈現出的活化量及電特性的研究。吾人實驗結果顯示矽化鎳經兩階段退火有助於介面狀態的改善，並且使活化的摻雜物朝介面堆積，接面呈現歐姆接觸(Ohmic Contact)。但是硼摻雜物當退火溫度超過550 ℃ 30 sec會發生短暫增強擴散(Transient Enhanced Diffusion)使硼向矽基材擴散,磷摻雜物則有不會發生此種現象。具有較強的溫度免疫力，可適用於高溫製程。硼則是具有較好的低溫活化能力。

In advanced CMOS devices, as contact dimensions scale down to nanometer range, contact resistance of source and drain is increased correspondingly. As a result, the technique of metal silicides for poly gate and source/drain has been developed to reduce the contact resistance and the parasitic junction resistance as well. In nanometer MOSFET fabrication, this silicidation process requires considering to suppress short channel effect (SCE) when forming the ultra shallow source and drain junction. Therefore, metal silicides owning a perfect interfacial property with Si above an ultra-shallow junction is considered as a critical module toward the realization of nano-scale CMOS. In the thesis, we want know the amount of activation and electro-characteristics by different thermal process. The experiments show that nickel silicide interface state improved by two-step rapid thermal annealing (RTA) process. And the activation dopant accumulates toward the interface. The junction presents ohmic contact. The implanted boron sample occur transient enhanced diffusion result in boron diffuse toward silicon substrate above 550 ℃ 30 sec. This phenomenon does not occur in the implanted phosphorous sample. Has the strong temperature immunity, suitably in high temperature process. However the boron has good activation ability atlow temperature.