Thermal Selective Vapor Etching of TiO2: Chemical Vapor Etching via WF6 and Self-Limiting Atomic Layer Etching Using WF6 and BCl3
Thermal Selective Vapor Etching of TiO2: Chemical Vapor Etching via WF6 and Self-Limiting Atomic Layer Etching Using WF6 and BCl3
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DOI：
10.1021/acs.chemmater.7b00985
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发表时间：
2017-08-22
影响因子：
8.6
通讯作者：
Parsons, Gregory N.
中科院分区：
文献类型：
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作者：
Lemaire, Paul C.;Parsons, Gregory N.
受控的薄膜蚀刻对于亚10 nm半导体器件的进一步发展是必不可少的。氧化物的气相热蚀刻对于实现高深宽比特征的高度共形蚀刻是有吸引力的。我们表明，六氟化钨（WF6）可用于选择性地蚀刻非晶TiO 2膜与其他氧化物，包括Al 2 O 3。采用石英晶体微天平（QCM）、椭圆偏振光谱仪、X射线光电子能谱（XPS）和热力学模型研究了WF6对TiO2的化学气相刻蚀（CVE）。XPS结果显示了在蚀刻过程中在TiO2膜上形成的WOxFy层的证据，其可以充当表面活性剂层以帮助实现TiO2的钝化。通过WF6的TiO2的直接CVE强烈地依赖于温度，其中蚀刻在220 ℃下容易进行，但在T
Controlled thin film etching is essential for further development of sub-10 nm semiconductor devices. Vapor-phase thermal etching of oxides is appealing for achieving highly conformal etching of high aspect ratio features. We show that tungsten hexafluoride (WF6) can be used to selectively etch amorphous TiO2 films versus other oxides including Al2O3. Chemical vapor etching (CVE) of TiO2 by WF6 was studied with quartz crystal microbalance (QCM), spectroscopic ellipsometry, X-ray photoelectron spectroscopy (XPS), and thermodynamic modeling. The XPS results show evidence for a WOxFy layer that forms on of the TiO2 films during the etch process, which may act as a surfactant layer to help enable fluorination of the TiO2. Direct CVE of TiO2 by WF6 is strongly temperature dependent, where etching proceeds readily at 220 degrees C, but not at T