CVD Cu 基本沈積特性及矽化鉭障礙層的熱穩定性之研究

Abstract

本論文探討銅化學氣相沈積的基本特性及以矽化鉭當作銅的擴散障礙層運用。第一部份以一種液態有機金屬複合體Cu(hfac)TMVS +2.4%TMVS當作先驅物，進行銅化學氣相沈積，並且以成長溫度、壓力為因，探討銅化學氣相沈積的活化能，以及銅膜的電阻率、表面型態等性質。在擴散障礙層部分，我們以電性和物性的角度，探討很薄(5nm及10nm)的矽化鉭薄膜在抵擋銅原子擴散的能力。以TaSi2為標靶所沈積10nm厚度之TaSixNy其熱穩定性可達500℃，而厚度減半為5nm，其熱穩定性只可達400℃。

This studies the basic characteristics of Cu CVD and the thermal stability of TaSixNy diffusion barrier for Cu metallization. A liquid metalorganic compound of Cu(hfac)TMVS+2.4%TMVS us used as the precursor for the study of Cu CVD. For the study of Cu CVD, we investigate the growth rate, resistivity, surface morphology, and crystallinity of the Cu films with and without thermal annealing. For the barrier thermal stability of very thin sputtered TaSixNy, the Cu/TaSixNy(10nm)/p+-n junction diodes were able to sustain a 30 min thermal annealing at temperatures up to 500℃ without degradation of the devices electrical characteristics. For comparison, the thermal stability was reduced to 400℃ for the Cu/TaSixNy(5nm)/ p+-n junction diodes. Abstract (Chinese)……………………………………………………… i Abstract (English) ……………………………………………………… ii Acknowledge……………………………………………………………… iii Contents……………………………………………………………….……..iv Table Captions………………………………………………………….…vi Figure Captions……………………………………………………….….vii Chapter 1 Introduction…………………………………………….….1 1.1 Multilevel Metallization in ULSI…………………………….…...1 1.2 The Needs of Cu…………………………………………….…….1 1.3 Thesis organization………………………………………….…….3 Chapter 2 Cu CVD System Configuration……………….……4 2.1 Multi-chamber apparatus…………………………………….……4 2.2 Auto-Controlled System…………………………………………...5 2.3 Reaction of Precursor………………………………………………6 Chapter 3 Chemical Vapor Deposition of Cu from Cu(hfac)TMVS……………………………………….……8 3.1 Introduction…………………………………………………….….8 3.2 Experimental Procedures……………………………………….….8 3.3 Results and discussions……………………………………10 3.3.1 Activation Energy of Cu CVD……………………………..10 3.3.2 Characteristics of Cu Film……………………………….…11 3.4 Summary……………………………………………………….….13 Chapter 4 Annealing Effects of CVD Cu films………….…..14 4.1 Introduction……………………………………….……………….14 4.2 Experimental procedures……………………………………..……14 4.3 Result and discussion………………………………………….…..15 4.3.1 Film resistivity……………………………………………..15 4.3.2 Surface morphology and grain size…………………………16 4.3.3 XRD analyses……………………………………………….16 4.4 Summary……………………………………………………….….17 Chapter 5 TaSixNy as Diffusion Barrier of Cu…………….….19 5.1 Introduction…………………………………………………….….19 5.2 Experimental procedure……………………………………….…..19 5.3 Result and discussion……………………………………….…….21 5.3.1 Electrical measurement……………………………….……21 5.3.2 Material analysis……………………………………….…..22 5.4 Summary……………………………………………………….….23 Chapter 6 Conclusion and Future Work…………………….…25 6.1 Conclusion…………………………………………………….…..25 6.2 Future work…………………………………………………….….26