磁性FePt薄膜MIM結構的崩潰電壓之特性

Abstract

磁性物質的研究及應用相當的廣泛，因此我們想將磁性物質加入半導體製程中，我們所選用的磁性物質為FePt，FePt具有相當大的晶格異向性、飽和磁化量和熱穩定性，我們發現磁性的FePt在MIM結構中具有增加崩潰電壓之效果，因此對其現象進行分析與討論。 本論文探討的內容主要分成三個部分，第一部分為磁性FePt薄膜的製程，我們可以發現FePt的磁性會受到FePt比例、退火的溫度、時間及不同方式退火所影響，因此我們經由實驗找出最佳化的條件，並將此條件加入MIM結構中。第二部分為Ta阻擋層對電性的影響，Fe有相當大的擴散速率，當擴散至絕緣層中時，會導致絕緣層漏電流增加，在磁性FePt MIM結構中加入Ta阻擋層可有效的避免Fe擴散至SiO2中。最後一部分為探討磁性FePt MIM結構之電性，電子穿隧機率在磁場下會降低，可使磁性FePt MIM結構之漏電流減少，產生高崩潰電壓，並以理論計算結果加以佐證。

Recently, there are a lot mounts of investigations about magnetic martial. In this magnetocrystalline anisotropy and saturated magnetization and of FePt are larger than other magnetic martial and chemical stability is better than others. We obtained a very high breakdown voltage in MIM structure with FePt. In this thesis, we will analyze and discuss this phenomenon. We can separate our research to three parts. First part is the fabrication of FePt. From the experimental results, we recognize atomic ratio of FePt, annealing temperature, time and various methods of annealing will affect the magnetism of FePt, and we also obtain the optimized conditions of process. In the second part, we recognize Ta can become the blocking layer to reduce the diffusion of Fe. In the last part, we discuss electrical characteristics of MIM capacitor. And we obtain higher breakdown and lower electron tunneling probability under magnetic field.