Vertical alignment (VA) of a liquid crystal display (LCD) device with a stable pretilt angle has been achieved on ion-bombarded silicon nitride (SiN(x)) surfaces. The surface energy variation of the SiN(x) surface with the bonding conversion achieved via ion beam bombardment makes it possible to control the liquid crystal (LC) pretilt angle. X-ray photoelectron spectroscopy revealed that the vertical orientation of the LC molecules occurs on the SiO(2) surface and that this orientation is directionally transformed upon ion bombardment of SiN(x) thin films. Moreover, the upgraded electro-optical characteristics of VA-LCDs showed potential for high-performance LCD applications on modified SiN(x) surfaces. (C) 2011 Elsevier B.V. All rights reserved.