Silver (Ag) film etching was studied with a focus on suppressing the surface roughness induced by Cl₂ and CF₄ plasmas. After Cl₂ plasma etching, roughening of the Ag surface was observed. From in situ x-ray photoelectron spectroscopy and atomic force microscopy analyses using a plasma beam system, the Ag surface was roughened with AgCl formation after Cl₂ plasma treatment before exposure to air. In capacitively coupled Cl₂ plasma, it seemed that many voids were formed on the Ag surface at a high bias power and cathode temperature. This was considered to be characteristic of agglomeration. In contrast, severe surface roughness was not observed after CF₄ plasma etching, even at a high bias power and cathode temperature. Secondary ion mass spectrometry analysis showed high chlorine accumulation near the Ag film surface after Cl₂ plasma etching. Possible agglomeration of the Ag film during Cl₂ plasma etching was volume expansion caused by chlorine accumulation assumed to enhance the compressive stress of the Ag film, and this resulted in increased boundary grooving and, finally, agglomeration. In contrast, fluorine accumulation was unlikely during CF₄ plasma etching, resulting in less Ag film stress, which suppressed grain boundary grooving and agglomeration.

中文翻译：

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使用卤素气体等离子体蚀刻银膜

研究银（Ag）膜蚀刻的重点是抑制由Cl ₂和CF ₄等离子体引起的表面粗糙度。在Cl ₂等离子蚀刻之后，观察到Ag表面的粗糙化。从原位X射线光电子能谱法和原子力显微镜使用等离子体束系统分析，银表面用氯后形成的AgCl粗糙化₂暴露于空气之前的等离子体处理。在电容耦合的Cl ₂等离子体中，似乎在高偏置功率和阴极温度下在Ag表面上形成了许多空隙。这被认为是聚结的特征。相反，CF ₄后未观察到严重的表面粗糙度等离子刻蚀，即使在高偏置功率和阴极温度下也是如此。二次离子质谱分析表明，在Cl ₂等离子体刻蚀之后，Ag膜表面附近有大量氯积累。在Cl ₂等离子蚀刻过程中，Ag膜可能发生的结块是由于氯的积累引起的体积膨胀，而氯的积累被认为会增强Ag膜的压应力，从而导致边界开槽增加，最终导致结块。相反，在CF ₄等离子体蚀刻过程中氟不太可能积累，从而导致较小的Ag膜应力，从而抑制了晶界开槽和结块。