低電阻率自我鈍化型銅銦合金薄膜之固溶特性及電性研究

Structural and passivate behaviors of Cu(In) thin film

謝馨儀(HsinYi Hsieh)

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2006年)

摘要

目前TFT-LCD製程中，Al導線因稍高電阻率、低熔點、與玻璃之熱膨脹係數差異致使容易產生高時間延遲與突出物生長現象，此缺點嚴重限制其應用於大尺寸TFT-LCD與高畫素及高畫像品質之面板發展。本研究製備低電阻率、具有自我鈍化能力之Cu(In)合金薄膜，希望能取代傳統鋁金屬導線以應用於TFT-LCD之積層元件。

實驗利用磁控共濺鍍法(co-sputter)，在康寧Eagle2000玻璃基板上製備380nm之CuInx (x =1.5-5 at.% )薄膜，並對Cu(In)合金薄膜做快速退火熱處理而產生In2O3/Cu/SiO2結構，以獲得低電阻率、高附著性與自我鈍化之銅薄膜。

由相結構分析中，除Cu與In2O3 結晶相外並無其他介金屬化合物生成，Cu(1.9 at.% In)薄膜於50 mTorr氧氣氛圍熱處理600˚C 10分鐘下得到研究中之最低電阻率為2.83 μΩ-cm，且在不同氧氣氛壓下做快速退火熱處理，發現In成分之增加將有助於在氧氣氛圍下自我鈍化效果的提升。由附著性測試可得Cu(In)薄膜對玻璃基板之附著性有非常顯著的提升，且於電漿沉積SiNx介電層過程，In2O3之生成能有效保持介面之完整性。

並列摘要

Aluminum and its alloys thin films are currently used as the primary gate line and date line on thin-film transistor because of their relatively low resistivity and self-passivated characteristics. Aluminum, however, suffers from major limitation such as electromigration and stress relaxation (introducing hillock and whisker), inducing an open-circuit failure. In the development of large-area and high resolution active matrix liquid crystal displays (AMLCDs), several drawbacks of aluminum thin film must be resolved. This work aims at preparing a low resistivity, high adhesion and self-passivated Cu alloy thin film, which will be potentially adopted at gate, source/drain on TFT-LCD.

Cu-In (1.5-5 at.%) films were prepared on Corning Eagle2000 glass substrate using a co-sputtering method, and subsequent annealing of the film in a range of 200-600°C for 10-30 min. Self-passivated copper in the form of In2O3/Cu/SiO2 has obtained when the Cu(In) alloy film was annealed at an elevated temperature. Post-annealed Cu(In) thin alloy films induce the the formation of In2O3/Cu bilayer and/or nanostructure.

Only copper diffraction peaks were detected for the as-deposited film.However, formation of In2O3 phase was observed when the film was annealed at a temperature above 400˚C . Among the studies, Cu(1.9 at. % In) thin film exhibits a lowest resistivity of 2.83 μΩ-cm.

The “scotch tape test” is used to evaluate the adhesion between Cu(In) film and glass substrate. The stacked film exhibits low resistivity, good adhesion to SiO2 and excellent passivation capability.

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