Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1523
標題: 薄膜應力與拋光應力對銅膜化學機械拋光行為影響之研究
A SYUDY ON THE EFFECTS OF FILM STRESS AND POLISHING STRESS ON COPPER CMP
作者: 謝耀儀
hsieh, yow yi
關鍵字: 膜濺鍍過程所殘留之應力;Film Stress;CMP
出版社: 機械工程學系
摘要: 
摘 要
化學機械拋光為半導體製程中最常用的平坦化製程,本文探討銅膜CMP拋光過程既有應力與外加應力對拋光製程材料移除之影響。前者為晶圓薄膜濺鍍過程所殘留之應力,後者為CMP拋光製程中所之施加應力。
本文以純腐蝕、純機械拋光及CMP拋光三組實驗進行分析。研究主要發現(1)沈積薄膜與退火後之薄膜均為張應力,張應力將使金屬鍵結受拉伸,進而促使腐蝕率增加。(2)退火後薄膜應力均增加,厚度為1,000nm與2,000nm銅膜之退火溫度愈高應力愈大;而厚度為1,500nm銅膜之退火溫度愈高應力反而下降。以相同退火溫度之實驗結果顯示,退火溫度為150°C及250°C時,薄膜應力愈大,導致較大的移除率。而退火溫度為200°C之銅膜,雖然應力愈大但移除率並沒有增加反而下降。(3)厚度為1,000nm銅膜之退火溫度愈高則應力愈大,對應的腐蝕速率也愈大。(4)以厚度1,000nm銅膜進行連續拋光,並量測其應力與厚度,結果顯示,當銅膜厚度低於450nm以下時,移除率明顯增加,當厚度低於此值時,既有應力將強烈影響移除率。(5)實驗顯示純機械拋光移除率甚低,其值小於20Å/min,顯示化學機械拋光之效應並非單純機械效應與化學效應之線性合成。

ABSTRACT
Chemical mechanical polishing (CMP) is the most commonly used process in the planarization of wafer surfaces. This thesis, from the stress viewpoint, investigates the effects of intrinsic stress and extrinsic stress on the removal rate of copper CMP. The former is the stress from the sputtering and annealing processes while the latter is the stress occurred in the polishing process.
Three types of experiments are designed and conducted in this thesis, including chemical corrosion, mechanical polishing, and CMP. Achievement of this study includes the following items: (1) The copper film after sputtering and annealing sustains tensile stress that intensifies corrosion rate. (2) Film stress increases after annealing. For copper film with 1,000 nm and 2,000 nm in thickness, the stress increases as the annealing temperature increases. For film of 1,500nm in thickness, the stress decreases with the annealing temperature. The corrosion rates of films with annealing temperature at 150C and 250C increase with film stress. But the rate decrease with film stress for copper film annealed at 200C. (3) The stress of 1,000nm thick copper film increases at high annealing temperature. Meanwhile, the corresponding corrosion rate increases. (4) Continuous polishing on 1,000nm copper film showed that the removal rate increases rapidly. The removal rate is strongly dependent upon film stress under this condition. (5) The removal rate of mechanical polishing, however, is relatively low. As the rate is less than 20/min, it indicates that the removal mechanism of CMP is not a simple superposition of chemical corrosion and mechanical polishing.
URI: http://hdl.handle.net/11455/1523
Appears in Collections:機械工程學系所

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