Plasma interactions with high aspect ratio patterned surfaces: ion transport, scattering, and the role of charging

• Published in: Thin solid films 2000-10, Vol.374 (2), p.175-180
• Main Authors: Giapis, K.P, Hwang, G.S
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Lithography, masks and pattern transfer; Materials science; Microelectronic fabrication (materials and surfaces technology); Microtrenching; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma applications; Plasma etching; Semiconductor; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sidewall bowing; Surface cleaning, etching, patterning; Surface treatments
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(00)01149-4

Etching of a patterned semiconductor surface in a plasma depends strongly on the transport of ion and neutral species between the features. Factors altering ion scattering at the sidewalls of high aspect ratio features, such as ion temperature, mask erosion, and charging, influence significantly the final profile shape. Models to describe the inelastic and reactive scattering at various surfaces, coupled to ion trajectory calculations in the sheath and between features, are used to illustrate the contribution of these factors to microtrenching and sidewall bowing. A transition in the profile shape from exhibiting microtrenching to having a rounded bottom is predicted as a result of plasma-induced charging in very high aspect ratio insulating masks.