半導體元件是由數層不同的厚度且材質互異的薄膜所構成，鎢薄膜做為柱塞(Plug)的用途，化學機械拋光(Chemical Mechanical Polishing, CMP)是半導體製程中全面平坦化(Global Planarization)的方法。但薄膜經CMP之後，表面材料移除同時伴隨有殘留應力的變化，殘留應力對薄膜結構及材料性質具有關鍵的影響。本研究量測鎢薄膜殘留應力，探討鎢薄膜化學機械拋光對其影響。研究方法規劃化學機械拋光與電化學拋光(Electrochemical Polishing, ECP)兩組實驗，以低掠角繞射法(Grazing Incidence X-Ray Diffraction, GIXRD)量測薄膜次表面殘留應力，將量測結果由LabView7.0軟體編輯程式，計算殘留應力值，計算結果與分析軟體(PANalytical X'Pert Stress)比較結果一致，計算值誤差來自不同的近似方式。化學機械拋光殘留應力量測結果，薄膜CMP殘留應力分佈為張應力的狀態，隨著深度的增加而遞減，次表面由於拋光液與薄膜之間化學作用生成氧化物，同時也受到磨料顆粒刮損的影響產生次表面破壞，由GIXRD檢測結果，次表面變質層分佈約21.3nm。電化學拋光殘留應力量測結果，薄膜ECP殘留應力分佈隨著深度的增加而遞減，次表面因為電解過程中受到電化學作用，電解液與薄膜之間生成氧化物，次表面變質層分佈約16nm。比較薄膜CMP與薄膜ECP殘留應力分佈曲線，去除移除厚度變化的影響，得知薄膜CMP製程參數殘留應力。由實驗設計，改變下壓力與相對轉速，得到薄膜CMP殘留應力變化的迴歸方程式作為預測式。未來研究可應用GIXRD量測不同材料薄膜殘留應力梯度的分佈，作為化學機械拋光製程參考，改善薄膜拋光後的品質。

Thin film layers with different properties and thickness are deposited on substrates for fabricate the semiconductor components. Tungsten thin film is usually as a plug. Chemical Mechanical Polishing (CMP) is widely applied in the semiconductor process to removal material for good planarization. But material property and residual stress state are affected by CMP process. This research is to estimate the residual stress of tungsten thin film deposited on the silicon wafer and investigate the effect induced by CMP. The Grazing Incidence X-Ray Diffraction (GIXRD) method is used in the research to measure the residual stress from CMP and electrochemical polishing (ECP) experiments. Residual stress is calculated by a developed method by Labview program and compared that with that by the PANalytical X'Pert Stress software. Results are very close and residual is from different fitting method. Residual stress distribution measurement results after CMP experiment are tensile and decrease gradually. The transition zone reveals the chemical oxidization layer interacted by slurry and the subsurface damage scratched by abrasive during CMP process. Results from ECP experiment reveal the chemical oxidization layer and the subsurface residual stress distribution affected during ECP process. From the residual stress distribution curves of W-films by CMP and ECP, the residual stress induced by abrasive reaction process can be obtained. Finally the regression model provides the estimation of residual stress due to the variation after CMP process. The residual stress distribution results of tungsten thin film can further be a reference in the CMP process to achieve desired thin films.

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