臺灣博碩士論文加值系統

本研究利用超高真空直流磁控濺鍍沉積系統，在氬氣及氮氣分壓分別固定3×10-1 Pa、2.66×10-2 Pa的反應性氣氛下，濺擊鈦靶(及鋁靶)，以在熱二氧化矽(Si/SiO2)基材上，生長厚度僅20 nm之TiN及Ti0.96Al0.04N、Ti0.92Al0.08N薄膜，並對這三種薄膜試片施加恆溫(350oC~550oC)、30分鐘之氧氣熱處理，以分析Al摻雜對於薄膜抗熱氧化性之差異。
相對片電阻分析及同步輻射X光繞射(XRD)分析結果顯示：經過450oC氧化處理以後，TiN薄膜已局部氧化成金虹石相(Rutile-TiO2)，並造成整體片電阻之激烈上升，而Ti0.92Al0.08N薄膜的片電阻僅微幅上升0.2倍，且XRD分析顯示並未產生任何TiO2。此外，二次離子質譜(SIMS)及高解析X光光電子能譜術(HR-XPS)兩種元素縱深分析顯示，經過相同的高溫氧氣環境處理以後，TiN薄膜內部之擴散程度已明顯的大於在Ti0.92Al0.08N的擴散程度，致使後者具有較高的殘留N元素訊號(O元素訊號則相對地較低)。鋁含量稍微降低的Ti0.96Al0.04N之抗氧化能力雖略遜於Ti0.92Al0.08N，但亦優於TiN。這些發現証實鋁摻雜可以有效提升TiN薄膜的高溫熱化學安定性及抗氧化能力。X光反射率比對分析證實：經450oC氧氣熱處理後的TiN與Ti0.92Al0.08N薄膜試片具有明顯差異之反射率週期與振幅，這些差異可能與TiAlN的Al產生偏析，或表面氧化層差異有關。TiAlN之抗氧化機制仍待澄清。

This study used reactive co-sputtering to deposit thin films of TiN and aluminum-minor-doped TiN (Ti0.96Al0.04N and Ti0.92Al0.08N) with a thickness of 20 nm on thermally oxidized SiO2 layer on p-type, (100) silicon. All the films were deposited under an optimal reactive atmosphere of fixed argon (3.0×10-1 Pa) and N2 (2.66×10-2 Pa), and were subsequently subjected to isothermal oxidized (O2) annealing at temperatures ranging from 350 to 550°C for 30 min. Doing so allows the resistance of the films against oxidization to be analyzed using x-ray diffraction (XRD), sheet-resistance measurement, second ion mass spectroscopy (SIMS), high-resolution x-ray photoelectron spectroscopy (HR-XPS), and x-ray reflection measurements.
After annealing at 450°C, TiN thin film was partially transformed into rutile-TiO2, and thus caused a marked increase in film’s overall sheet resistance by eight times. However, the phase (and the overall sheet resistance) of Ti0.92Al0.08N thin film remained as normal even after the identical annealing. Regarding the oxidization resistance, the Ti0.96Al0.04N (with reduced amount of Al) thin film is inferior to Ti0.92Al0.08N thin film, but outperforms TiN. These findings imply that doing a lightly amount of Al indeed can elevate the oxidization resistance of the nitride films. While the spectra of x-ray reflectivity between the samples of TiN and Ti0.92Al0.08N thin films differ significantly, the mechanism of strengthening oxidization by Al doping remains to be clarified.

摘要……………………………………………………………………I
Abstract………………………………………………………………III
目錄……………………………………………………………………IV
圖目錄…………………………………………………………………VI
表目錄………………………………………………………………IX
第1章、前言…………………………………………………………1
第2章、文獻回顧與研究動機…………………………………………5
2.1反應性磁控濺鍍TiN薄膜特性………………………………5
2.1.1反應性磁控濺鍍原理…………………………………5
2.1.2 TiN微結構、物理性質與應用………………………6
2.2 Al摻雜之TiN薄膜衍生之抗氧化薄膜應用…………………8
2.2.1 Al摻雜之TiN薄膜結構與特性……………………8
2.2.2製TiAlN硬膜於高溫抗氧化之應用…………………9
2.2.3 TiAlN擴散阻礙層在銅製程之應用…………………11
2.2.4 TiAlN抗電極氧化薄膜於DRAM之應用…………12
2.3研究主題…………………………………………………14
第3章、實驗步驟………………………………………………………22
3.1薄膜試片製備與後續氧化處理…………………………22
3.1.1薄膜沉積………………………………………………22
3.1.2後續氧化處理…………………………………………23
3.2試片分析………………………………………………24
3.2.1 TiN及TiAlN薄膜氧化現象與分析………………24
3.2.2 TiN及TiAlN薄膜之抗氧化機制探討…………………25
3.3分析儀器簡介………………………………………………26
第4章、結果與討論…………………………………………………42
4.1薄膜基本特性………………………………………………42
4.2薄膜抗熱氧化特性－電性分析……………………………44
4.3薄膜抗熱氧化特性－相與結構分析(XRD/XAS)…………45
4.4薄膜抗熱氧化特性－SIMS縱深分佈分析…………………48
4.5薄膜抗熱氧化特性－HR-XPS縱深分佈分析……………51
4.6薄膜抗熱氧化特性－反射率分析…………………………55
第5章、結論…………………………………………………………72
參考文獻………………………………………………………………74
圖 目 錄
圖1.1 DRAM之結構示意圖……………………………………………4
圖2.1 TiN平衡相圖…………………………………………………16
圖2.2晶體結構示意圖(a)TiN；(b)TiAlN………………………17
圖2.3 Al元素在TiAlN薄膜內之三種高溫擴散行………………18
圖2.4模擬MIM元件示意圖…………………………………………19
圖2.5腐蝕電位(Ecorr)對應腐蝕電流(Icorr)之極化曲線分析圖 (a)剛沉積TiN薄膜(b)剛沉積TiAlN薄膜…………………………20
圖3.1超高真空濺鍍系統結構示意圖………………………………32
圖3.2高溫水平管爐示意圖…………………………………………33
圖3.3薄膜特性掌握與抗熱氧化評估流程之示意圖…………………34
圖3.4傳統掠角X光繞射儀分析熱處理前後之TiN薄膜試片繞射圖譜………………………………………………………………35
圖3.5階梯量測薄膜厚度的示意圖…………………………………36
圖3.6四點探針量測薄膜片電阻示意圖………………………36
圖3.7典型之X光反射率實驗配置示意圖……………………37
圖3.8在Si基材上沉積10 nm之Pt與30 nm之Ti薄膜之理論X光反射率曲線…………………………………………………37
圖3.9本實驗使用之掠角XRD分析示意圖………………………38
圖3.10材料表面二次離子產生示意圖……………………………38
圖4.1沉積速率與電阻率對應Al靶功率之關係圖………………57
圖4.2剛沉積薄膜之平視野穿透式電子顯微照片：（a）TiN明場與暗場(右下插圖)影像,（b）TiAlN明場與暗場(右下插圖)影像………………………………………………………………58
圖4.3片電組相對變化量(rRs/Rs)對應氧氣氛退火溫度曲線( Rs = 剛沉積試片電阻、Rs = 退火前、後片電阻差)關係圖。(a)Si/SiO2/TiN、(b) Si/SiO2/ Ti0.96Al0.04N、(c) Si/SiO2/ Ti0.92Al0.08N……………………………………………………59
圖4.4 TiN薄膜在不同氧氣退火溫度之XRD繞射圖譜……………60
圖4.5 (a)TiN薄膜，經O2/550oC/30 min.氧氣環境熱處理後之Ti K-edge吸收光譜(17C光束線)、(b)文獻所示之TiO2 Ti K-edge吸收光譜。…………………………………………………………61
圖4.6 Ti0.92Al0.08N薄膜在不同氧氣退火溫度之XRD繞射圖譜………………………………………………………………62
圖4.7 氧氣退火熱處理30 min.之Si/SiO2/TiN試片SIMS縱深圖譜。(a)剛沉積、(b) 350oC、(c)450oC及(d)550oC…………………63
圖4.8 氧氣退火熱處理30 min.之Si/SiO2/ Ti0.96Al0.04N試片SIMS縱深圖譜。(a)剛沉積、(b) 350oC、(c)450oC及(d)550oC……………64
圖4.9 氧氣退火熱處理30 min.之Si/SiO2/ Ti0.92Al0.08N試片SIMS縱深圖譜。(a)剛沉積、(b) 350oC、(c)450oC及(d)550oC…………65
圖4.10氧氣退火熱處理30 min.之Si/SiO2/ TiN試片HR-XPS縱深圖譜。(a)剛沉積、(b) 425oC、(c) 450oC………………………66
圖4.11氧氣退火熱處理30 min.之Si/SiO2/ Ti0.96Al0.04N試片HR-XPS縱深圖譜。(a)剛沉積、(b) 450oC……………………………67
圖4.12氧氣退火熱處理30 min.之Si/SiO2/ Ti0.92Al0.08N試片HR-XPS縱深圖譜。(a)剛沉積、(b) 425oC、(c) 450oC………………68
圖4.13 Si/SiO2/ TiN與Si/SiO2/ Ti0.92Al0.08N試片經過450oC氧氣退火熱處理30 min.之反射率分析曲線。…………………………69

表 目 錄
表1.1用於DRAM之高介電常數材料…………………………………4
表2.1 Al含量與結構關係……………………………………………21
表2.2 TiAlN應用於傳統熱機械硬膜、DRAM中之抗電極氧化薄膜、與本實驗室所研究之擴散阻礙層之比較………………21
表3.1 SCⅠ與SCⅡ成分及主要優缺點………………………………40
表3.2反應性濺鍍沉積Ti(Al)N薄膜之整體製程條件……………40
表3.3四點探針電阻率換算修正因子對照表………………………41
表4.1剛沉積TiN、Ti0.96Al0.04N及Ti0.92Al0.08N薄膜之原子百分比…………………………………………………………70
表4.2 450oC氧氣退火熱處理後之TiN、Ti0.96Al0.04N及Ti0.92Al0.08N薄膜表面原子百分比…………………………………71
表4.3 450oC氧氣退火熱處理後的TiN、Ti0.96Al0.04N及Ti0.92Al0.08N薄膜濺擊深度為75 sec之原子百分比………………71
表4.4 450oC氧氣退火熱處理後的TiN、Ti0.96Al0.04N及Ti0.92Al0.08N薄膜濺擊深度為130 sec之原子百分比……………71

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