Characteristics of Nitrogen Doped Zr-Ti-Ni Thin Film Metallic Glass and Application to Ultra-Thin Diffusion Barrier

金屬玻璃這項特殊的材料是由熔融態金屬經由快速焠火得到的非晶態合金。金屬玻璃所擁有的優秀機械性質與因為非晶態結構而衍伸出地獨特性質諸如耐腐蝕與軟磁性等都吸引過去數十年來許多學者深入探索了許多金屬玻璃發展的可能性與成分。然而金屬玻璃的高技術取向製程與較差的延展性都大大限制了其在工業或大型應用上的可能性。作為改善這項困境的辦法，金屬玻璃薄膜成為目前金屬玻璃發展的新研究與應用方向。金屬玻璃薄膜具有金屬玻璃所有擁有的特性如機械性質、熱塑性與耐腐蝕性。更重要的是金屬玻璃薄膜製程遠比金屬玻璃簡單，利用合金靶材濺鍍製程即可製造出非晶態之金屬玻璃薄膜。金屬玻璃薄膜的簡易製程也使得吾人能夠輕易調整金屬玻璃薄膜成分以達到更佳的機械性質或是特殊的應用如醫療用植入性材料等。本實驗探討了氮參雜對於鋯鈦鎳金屬玻璃薄膜的影響。本實驗為了更進一步增進此鋯基金屬玻璃薄膜的機械性質，本實驗選擇在製程中通入氮來對氮化金屬玻璃薄膜性質做系統性的完整研究。實驗證實在金屬玻璃薄膜中參雜15.8%的氮原子就能將硬度提升至未含氮金屬玻璃的三倍左右。參入的氮原子會在玻璃基底形成叢聚，並能夠有效的強化薄膜強度。鋯鈦鎳金屬玻璃也被應用於銅矽介面的超薄擴散阻障層。本實驗在金屬玻璃中參雜0/15.8/20.9% 的氮來形成三種擴散阻障層，並探討其熱穩定性差異和失效機制。實驗證明鋯鈦鎳金屬玻璃具有優秀的熱穩定性，並能夠保持結構完整直到最高八百度退火後才失效。氮原子被證實能夠有效的阻止銅擴散過阻障層，並形成新的保護層以提升整體結構的熱穩定。Bulk metallic glasses (BMGs), which are fabricated by rapid quenching from melting metallic alloys, have developed for decades. Thanks to their amorphous structure, BMGs have excellent mechanical and many special properties. However the application of BMGs is restricted by their difficult process and poor ductility. Thin film metallic glass (TFMG) is a new research direction for metallic glass, which has almost all merits of BMGs. The major difference between BMGs and TFMGs is that it is easier to fabricate TFMGs than BMGs. In this thesis, the effect of doping nitrogen into Zr-Ti-Ni thin film metallic glass, which has great mechanical properties, was investigated systematically. Nitrogen- doping was proved to have obvious effect on Zr-Ti-Ni TFMGs’ mechanical properties and their microstructures. The hardness and scratch resistivity of Zr-Ti-Ni TFMG with 15.8% N content were much higher than nitrogen-free TFMG for three times, which was enhanced by solute clusters existed in amorphous matrix. The performance of Zr-Ti-Ni thin film metallic glass (TFMG) as a diffusion barrier between silicon and copper layers is also reported. TFMG diffusion barriers in 5 nm thicknesses with 0/15.8/20.9% nitrogen contents were proved to have great thermal stability and nitrogen atoms play the critical role for retarding barriers failure; i.e., the thermal stability of Zr based TFMG contained 20.9% N is better than other two kinds of TFMG.口試委員審定書 I 致謝 II 中文摘要 III Abstract IV Chapter 1 Preface 1 1.1 Preface 1 1.2 Motivation of Study 2 Chapter 2 Literature Review 4 2.1 Bulk Metallic Glasses (BMGs) 4 2.1.1 Properties of Bulk Metallic Glasses 4 2.2.2 Development and Application of Bulk Metallic Glasses 6 2.2 Thin Film Metallic Glass 11 2.2.1 Properties of Thin Film Metallic Glass 11 2.2.2 Development and Application of Thin Film Metallic Glass 14 2.3 Diffusion Barrier in Copper Metallization 17 2.3.1 Introduction 17 2.3.2 Barrier Material Choice 22 2.4 Principle of Sputtering 26 2.4.1 Sputtering theory and plasmas 26 2.4.2 RF sputtering and magnetron sputtering 27 2.5 Nanoindentation 30 2.5.1 Introduction 30 2.5.2 Basic Theory 31 Chapter 3 Experimental Process 35 3.1 Experimental flow 35 3.2 Deposition Processes 37 3.2.1 Target and Substrate Preparation 37 3.2.2 Sputtering System 37 3.2.3 Sputtering parameters 39 3.3 Analysis Equipment 43 3.3.1 Rapid Thermal Annealing (RTA) 43 3.3.2 Differential Scanning Calorimetry, (DSC) 43 3.3.3 Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometry (EDS) 44 3.3.4 X-ray Diffractometer (XRD) 44 3.3.5 Transmission Electron Microscopy (TEM) and Focus Ion Beam (FIB) 45 3.3.6 TEM samples preparation 45 3.3.7 Four-Point Probe (FPP) 46 3.3.8 Electron Probe X-Ray Microanalyzer (EPMA) 46 3.3.9 Nanoindentator 47 Chapter 4 Nitrogen-doped TFMG Properties 52 4.1 Background 52 4.2 Properties of Nitrogen-Doped Zr-Ti-Ni Thin Film Metallic Glasses 53 4.2.1 Composition and Thermal Properties 53 4.2.2 Crystallization Behavior 56 4.2.3 Cross-Section Morphologies 58 4.2.4 TEM Cross-Section Images 60 4.2.5 Mechanical Properties 62 4.2.6 Adhesion Scratch Test 70 4.3 Effects of Annealing of Nitrogen-Doped Zr-Ti-Ni Thin Film Metallic Glasses 74 4.3.1 XRD Phase Identification 74 4.3.2 Mechanical Properties 78 4.4 Conclusions 83 Chapter 5 Application in Diffusion Barrier 84 5.1 Background 84 5.2 Long Time Annealing Durability 85 5.2.1 Sheet Resistance Measurement 86 5.2.2 TEM Cross-Section Images 87 5.3 High Temperature Annealing Durability 89 5.3.1 Sheet Resistance Measurement 89 5.3.2 XRD Phase Identification 91 5.3.3 SEM Surface Morphology 96 3.3.4 TEM Cross-Section Images 99 3.3.5 Adhesion Test 106 5.4 Conclusions 108 References 10