Abstract: A method for correcting pattern critical dimension (CD) in a photomask includes forming a multilayer structure over a substrate by stacking at least two thin films capable of forming a compound by application of energy from an energy source; forming a light-shielding layer over the multilayer structure; forming a light-shielding layer pattern that selectively exposes the multilayer structure by selectively etching the light-shielding layer; detecting a correction region requiring a CD correction by measuring a CD of the light-shielding layer pattern; and forming a compound, by which the CD is corrected by a transmittance difference between the multilayer structure and the correction region, by applying an energy to a region of the multilayer structure corresponding to the detected correction region to react the thin films.

Abstract: A photomask comprises: a light transmitting substrate; patterns disposed over the light transmitting substrate to define a light transmitting region; and a light transmittance control layer disposed between the light transmitting substrate and the patterns having a relatively high light transmittance in a first control layer region overlapping a first portion of the light transmitting region adjacent to a poor pattern having a size larger than a normal size than in a second control layer region overlapping a second portion of the light transmitting region between normal patterns having a normal size.

Abstract: Disclosed herein is a method of correcting defects in photomasks. According to one embodiment, a light absorption layer is formed on a photomask where pin hole defects occur in a light blocking layer, and light absorption patterns are formed on the pin hole defect portions by selectively etching the light absorption layer. According to another embodiment, a light absorption layer is formed on a backside of a photomask having pin hole defects in a light blocking layer, and light absorption patterns are formed on the backside of the photomask substrate corresponding to a region having pin hole defects by etching the light absorption layer.

Abstract: A method for fabricating a photomask includes forming a light blocking layer, a hard mask layer, and a resist layer on a transparent substrate, forming a resist pattern to selectively expose the hard mask layer by removing the resist layer selectively, forming a hard mask pattern by etching the exposed hard mask layer using the resist pattern as an etch mask, exposing the hard mask pattern by removing the resist pattern; measuring a critical dimension of the exposed hard mask pattern, correcting the measured critical dimension of the hard mask pattern to correspond to a critical dimension of a target pattern, forming a light blocking pattern by etching the exposed light blocking layer using the corrected hard mask pattern as an etch mask, and removing the hard mask pattern.

Abstract: A photomask is formed on an etch target layer of a transparent substrate using a blank mask that includes a carbon layer and an oxide layer. The carbon layer and the oxide layer are disposed on the etch target layer. The oxide layer is formed into an oxide layer pattern by photolithography for selectively exposing the etch target layer. A carbon layer pattern is formed by etching the carbon layer using the oxide layer pattern. An etch target layer pattern is formed by etching the etch target layer using the carbon layer pattern as a hard mask. Therefore, a sufficient thickness of the carbon layer can be etched using a thin oxide layer pattern employing the etch selectivity characteristics of the oxide layer and the carbon layer. Furthermore, the etch target layer pattern can have a predetermined vertical profile. The carbon layer pattern can be removed using oxygen plasma without damaging the underlying etch target layer pattern.

Abstract: A method for repairing a bridge in a photo mask includes disposing a phase shift layer pattern and a light shielding layer pattern over a transparent substrate with the phase shift layer pattern disposed between the transparent substrate and the light shielding layer, forming a resist layer over the entire surface of the photo mask having a defective pattern causing a bridge between neighboring portions of the phase shift layer pattern; exposing the defective pattern by etching the resist layer; and removing the exposed defective pattern.