In this work, thermally evaporated aluminum (Al) was used as hardmask (HM) to obtain silicon microchannels (SiMCs), using an Inductively Coupled Plasma - Reactive Ion Etching (ICP-RIE) system, in SF6/Ar gas mixture environment. The channel depth must be greater than 50 μm, with a high aspect ratio. For this, Al HM lines were defined by photolithography and by Al wet etching on a silicon substrate. To improve the resistance against the ICP-RIE etching process, the Al HMs were treated with four different conditions: i) Al HM without treatment step (control sample); ii) with plasma nitridation (AlN/Al structure); iii) with thermal annealing (annealed Al film); iv) with plasma nitridation and annealing (annealed AlN/Al structure). After 100 min of ICP-RIE etching process, SiMC with depths of 90.6 μm, 95 μm, 91.2 μm, and 109 μm, respectively, were measured using a scan profiler system. As the main result, the annealed AlN/Al structure presented a high resistance against the ICP-RIE etching for 100 minutes. Furthermore, Scanning Electron Microscopy (SEM) images indicate an etch uniformity on the walls and bottom of the channels for all the samples. This parameter is a mandatory requirement to obtain the integrated microchannel liquid-cooling technology for heat sinks in photovoltaic cells and Complementary Metal-Oxide-Semiconductor microprocessors.

中文翻译：

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使用不同铝硬掩模通过 ICP-RIE 等离子蚀刻工艺定义硅微通道


在这项工作中，采用热蒸发铝 (Al) 作为硬掩模 (HM)，在 SF6/Ar 混合气体环境中使用感应耦合等离子体 - 反应离子蚀刻 (ICP-RIE) 系统获得硅微通道 (SiMC)。通道深度必须大于50μm，具有高深宽比。为此，通过光刻和硅基板上的铝湿法蚀刻来定义铝 HM 线。为了提高对 ICP-RIE 蚀刻过程的抵抗力，用四种不同的条件处理 Al HM： i) 没有处理步骤的 Al HM（对照样品）； ii) 等离子氮化（AlN/Al 结构）； iii) 热退火（退火铝膜）； iv) 等离子氮化和退火（退火 AlN/Al 结构）。经过 100 分钟的 ICP-RIE 蚀刻过程后，使用扫描轮廓仪系统测量了深度分别为 90.6 μm、95 μm、91.2 μm 和 109 μm 的 SiMC。主要结果是，退火后的 AlN/Al 结构对 ICP-RIE 蚀刻 100 分钟表现出高耐受性。此外，扫描电子显微镜 (SEM) 图像表明所有样品的通道壁和底部的蚀刻均匀性。该参数是获得光伏电池和互补金属氧化物半导体微处理器散热器的集成微通道液体冷却技术的强制性要求。