Controlling the Cerium Oxidation State During Silicon Oxide CMP to Improve Material Removal Rate and Roughness
Controlling the Cerium Oxidation State During Silicon Oxide CMP to Improve Material Removal Rate and Roughness
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DOI：
10.1149/2162-8777/ab8393
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发表时间：
2020-04-06
影响因子：
2.2
通讯作者：
Dunn, K.
中科院分区：
文献类型：
--
作者：
Netzband, C. M.;Dunn, K.
使用关于改变二氧化铈表面上的Ce 3 +%的机制所获得的知识来产生二氧化铈浆料，该二氧化铈浆料以比目前工业中使用的浆料更高的材料去除速率（MRR）和更低的抛光后粗糙度来抛光热氧化物。如梳齿模型所述，氧化物去除最容易发生在表面键较少的位置。这允许用具有高MRR的大尺寸（68 nm）颗粒制备浆料，同时获得等于小得多的颗粒（5 nm）的粗糙度值。过氧化氢的加入首先增加了颗粒表面上的Ce 3 +%浓度，然后降低了它。这种趋势被MRR和粗糙度所复制，最初有所改善，直到达到阈值，之后所有的指标都变差。pH的影响更为复杂，因为它以两种方式影响抛光过程，即通过控制与二氧化铈的化学反应速率以及二氧化硅水解的速率，这反过来又决定了化学和机械去除的容易程度。(C)2020作者（S）由IOP Publishing Limited代表电化学学会出版。
Knowledge obtained on the mechanism for altering the Ce3+% on the ceria surface was used to create ceria slurries that polished thermal oxide with higher material removal rate (MRR) and lower post-polish roughness than slurries that are currently being used in industry. As described by the tooth-comb model, oxide removal occurs easiest at sites with fewer surface bonds. This allows for slurries to be prepared with particles of large size (68 nm) that have high MRR while obtaining roughness values that are equal to those of much smaller particles (5 nm). The addition of hydrogen peroxide initially increases the Ce3+% concentration on the particle surface, then decreases it. This trend is replicated by both MRR and roughness with improvements initially, until a threshold is reached, after which all of the metrics got worse. The effect of pH was more complex, as it impacts the polishing process in two ways, by governing the rate of the chemical reaction with ceria and also the rate at which silica hydrolyzes, which in turn determines the ease with which both chemical and mechanical removal occurs. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.