The core sequence: A nanoscale fluorocarbon-free silicon plasma etch process based on SF6/O2 cycles with excellent 3D profile control at room temperature

Autor: Roy Cork, Henri Jansen, Peixiong Shi, Flemming Jensen, Meint J. de Boer, Vy Thi Hoang Nguyen, Pele Leussink, Chantal Silvestre, Kechun Ma, Jörg Hübner
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: ECS journal of solid state science and technology, 9(2):024002. The Electrochemical Society Inc.
Nguyen, V T H, Silvestre, C, Shi, P, Cork, R, Jensen, F, Hubner, J, Ma, K, Leussink, P, de Boer, M & Jansen, H 2020, ' The CORE Sequence: A Nanoscale Fluorocarbon-Free Silicon Plasma Etch Process Based on SF 6 /O 2 Cycles with Excellent 3D Profile Control at Room Temperature ', ECS Journal of Solid State Science and Technology, vol. 9, no. 2, 024002 . https://doi.org/10.1149/2162-8777/ab61ed
ISSN: 2162-8769
DOI: 10.1149/2162-8777/ab61ed
Popis: This study focuses on the development of a fluorocarbon-free directional silicon etching process, called CORE (Clear, Oxidize, Remove, and Etch) in which a switching sequence of SF6 and O2 is operated at room temperature. This distinguishes it from the old-fashioned room temperature and cryogenic mixed RIE processes as CORE enables a higher selectivity, creates pattern independency of etching profiles and works excellent at room temperature. The CORE process resembles the well-known SF6-based Bosch process, but the usual C4F8 inhibitor is replaced by O2 oxidation with self-limiting characteristics. Therefore the CORE result is similar to Bosch, however has the advantage of preventing the pile-up of fluorocarbon deposits at the topside of deep-etched or nano-sized features. At the same time, process drift is minimized as the reactor wall is staying perfectly clean. The CORE process has shown an excellent performance in high aspect ratio (3D) nanoscale structures with an accurate and controllable etch rate between 1 and 50 nm min−1 (and SiO2-selectivity of ca. 35) using the etch-tool in the RIE-mode. By adding the ICP source (DRIE-mode), a directional etch rate up to 1 μm min−1 (at 50 sccm SF6 flow) and selectivity >200 for SiO2 is possible.
Databáze: OpenAIRE