磁性FePt奈米點MIS電容的異值崩潰電壓的特性與分析

Abstract

在半導體的領域中，研究的主流往往是矽半導體、高介電材料、三五族復合物。多數被視為前段製程汙染物的磁性材料在半導體界上的應用則顯得特別的少，然而，我們發現磁性物質應用在金-氧-半電容中卻有增強電場電度的特殊現象。而本論文就以此現象進行分析與討論，用量子力學的觀點來解釋並以模擬軟體加以佐證。 本論文討論分為兩大部分，第一部分為磁性薄膜FePt的製備為分析，其中我們也探討了磁性與熱退火的關係，另一部分則在電容中埋入磁性奈米點，並探討其在極薄氧化層(34nm)中異常高的崩潰電壓(49.2V)，並以量子力學及COMSOL複合物理模擬軟體去解釋在磁場下電子的波函數發生的localize效應。藉由討論磁性奈米點金氧半電容的漏電現象來間接應證磁性物質在介電層中的載子傳輸機制的影響。

In the field of semiconductor, the main stream research is always on standard process, such as Si-based semiconductor, high-κmaterial, III-V compound semiconductor. However, the research of magnetic material applied in semiconductor is very rare. However, using magnetic effects into semiconductor, insulator, metal, superconductor related structures will open up a huge possibilities of new phenomena , new devices, new applications. In spite of that, we have found some novel characteristics in MIS capacitor with magnetic nanodot. This thesis we have found the anomalous breakdown strength and leakage of magnetic nanodot in insulator. We presented in two parts, one is focus on FePt magnetic films fabrication, the second is that embedded FePt magnetic nanodot in oxide in MIS structure. First, FePt and oxide are deposited layer by layer. After furnace annealing, FePt dispense in oxide and induce to vertical and parallel magnetic field. This Capacitor has the anomalous huge breakdown voltage about 49V was observed in MIS capacitors with 34 nm oxide layer. We can also find huge voltage strength and we try to explain this phenomenon by quantum mechanical simulations. On the other hand, fitting its leakage current density to find carrier transport mechanism .We also found that the wavefunction is localized under strong magnetic field in COMSOL simulation. Unfortunately, verification of leakage current reduces due to magnetic field has not been observed due to lack of comparison between second set of samples. It will be further explained in the future. The tunneling probability reduced result from magnetic field quantum confinement effect. Therefore, carriers transport with other model, which quantum respect could explain.