In this study, etching characteristics of oval-sbaped contact were investigated. The oval-shaped contact showed different etching characteristics compared to the circular contact. The long axis cross-section of oval-sbaped contact showed a more vertical profile and a less bowing compared to the short axis. To explain these phenomena, we simulated ion reflection from sloped oval-shaped hard-mask. From the simulation, we found that the ions reflected from hard-mask accumulated more toward short axis sidewall first. This ion accumulation and asymmetric charging explained the reason behind larger bowing and slopped profile phenomena of short axis. (c) 2006 Elsevier B.V. All rights reserved.