Effect of oxygen addition to an argon plasma on etching selectivity of poly(methyl methacrylate) to polystyrene
Effect of oxygen addition to an argon plasma on etching selectivity of poly(methyl methacrylate) to polystyrene
复制标题
氩等离子体中添加氧气对聚甲基丙烯酸甲酯对聚苯乙烯蚀刻选择性的影响
DOI：
10.1117/1.jmm.12.4.041309
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
H. Yoshida
中科院分区：
文献类型：
--
作者：
M. Satake;T. Iwase;M. Kurihara;N. Negishi;Y. Tada;H. Yoshida
抽象的。研究了在氩等离子体中加入氧气对聚甲基丙烯酸甲酯（PMMA）对聚苯乙烯（PS）的刻蚀选择性（以下称为“PMMA/PS刻蚀选择性”）的影响。PMMA/PS蚀刻选择性评价通过使用由氩气和氧气组成的电感耦合等离子体。在氩等离子体的情况下的蚀刻选择性被估计为3.9，这高于氧等离子体的蚀刻选择性（其为1.7）。腐蚀深度的时间依赖性表明，当腐蚀深度超过15 nm时，PMMA的腐蚀速率降低到初始值的一半以下。PMMA表面的X射线光电子能谱表明，蚀刻速率的降低是由氩离子轰击引起的氧浓度耗尽引起的。为了补偿氧浓度损耗，向氩等离子体中加入1%的氧。结果，抑制了PMMA蚀刻速率的降低，并且即使当蚀刻深度超过50 nm时也获得恒定的蚀刻速率。使用混合氩-氧等离子体来制造具有在25.5至77 nm范围内的全间距的PS掩模图案。
Abstract. The effect of oxygen addition to an argon plasma on the etching selectivity of poly(methyl methacrylate) (PMMA) to polystyrene (PS) (hereafter “PMMA/PS etching selectivity”) was investigated. The PMMA/PS etching selectivity was evaluated by using inductively coupled plasmas composed of argon and oxygen. The etching selectivity in the case of argon plasma was estimated to be 3.9, which is higher than that of oxygen plasma, which is 1.7. The time dependence of etching depth shows that the etching rate of PMMA is reduced to less than one half of its initial value after the etching depth exceeds 15 nm. X-ray photoelectron spectroscopy of the PMMA surface revealed that the reduction of etching rate is caused by a depletion of oxygen concentration by argon-ion bombardment. To compensate the oxygen-concentration depletion, 1% oxygen was added to the argon plasma. As a result, the reduction of PMMA etching rate was suppressed, and constant etching rate was obtained even when etching depth exceeded 50 nm. The mixed argon-oxygen plasma was used to fabricate a PS mask pattern with a full pitch in the range of 25.5 to 77 nm.