Thermally Driven Self-Limiting Atomic Layer Etching of Metallic Tungsten Using WF6 and O2
| Autor: | Paul C. Lemaire, Gregory N. Parsons, Wenyi Xie |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Transistor Analytical chemistry chemistry.chemical_element Self limiting 02 engineering and technology Quartz crystal microbalance Tungsten 021001 nanoscience & nanotechnology 01 natural sciences law.invention Metal chemistry law Etching (microfabrication) visual_art 0103 physical sciences Thermal visual_art.visual_art_medium General Materials Science 0210 nano-technology Layer (electronics) |
| Zdroj: | ACS Applied Materials & Interfaces. 10:9147-9154 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.7b19024 |
| Popis: | The semiconductor industry faces a tremendous challenge in the development of a transistor device with sub-10 nm complex features. Self-limiting atomic layer etching (ALE) is essential for enabling the manufacturing of complex transistor structures. In this study, we demonstrated a thermally driven ALE process for tungsten (W) using sequential exposures of O2 and WF6. Based on the insight gained from the previous study on TiO2 thermal ALE, we proposed that etching of W could proceed in two sequential reaction steps at 300 °C: (1) oxidation of metallic tungsten using O2 or O3 to form WO3(s) and (2) formation and removal of volatile WO2F2(g) during the reaction between WO3(s) and WF6(g). The O2/WF6 etch process was experimentally studied using a quartz crystal microbalance (QCM). We find that both the O2 and WF6 ALE half reactions are self-limiting, with an estimated steady-state etch rate of ∼6.3 A/cycle at 300 °C. We also find that etching of W proceeds readily at 300 °C, but not at temperatures lower tha... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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