A method for forming a photomask includes receiving a mask substrate including a protecting layer and a shielding layer formed thereon, removing portions of the shielding layer to form a patterned shielding layer, and providing a BSE detector to monitor the removing of the portions of the shielding layer. When a difference in BSE intensities obtained from the BSE detector is greater than approximately 30%, the removing of the portions of the shielding layer is stopped. The BSE intensity in following etching loops becomes stable.

A method for forming a photomask includes receiving a mask substrate including a protecting layer and a shielding layer formed thereon, removing portions of the shielding layer to form a patterned shielding layer, and providing a BSE detector to monitor the removing of the portions of the shielding layer. When a difference in BSE intensities obtained from the BSE detector is greater than approximately 30%, the removing of the portions of the shielding layer is stopped. The BSE intensity in following etching loops becomes stable.

Method for the particle beam-induced etching of a lithography mask, more particularly a non-transmissive EUV lithography mask, having the steps of: a) providing the lithography mask in a process atmosphere, b) beaming a focused particle beam onto a target position on the lithography mask, c) supplying at least one first gaseous component to the target position in the process atmosphere, where the first gaseous component can be converted by activation into a reactive form, where the reactive form reacts with a material of the lithography mask to form a volatile compound, and d) supplying at least one second gaseous component to the target position in the process atmosphere, where the second gaseous component under predetermined process conditions with exposure to the particle beam forms a deposit comprising a compound of silicon with oxygen, nitrogen and/or carbon.

The inventive concept provides a mask treating apparatus. The mask treating apparatus includes a support unit configured to support and rotate a mask, the mask having a first pattern within a plurality of cells thereof and a second pattern outside regions of the plurality of cells; a heating unit including a laser irradiation module and a moving module, the laser irradiation module having a laser irradiator for irradiating a laser light to the second pattern, the moving module configured to change a position of the laser irradiation module; and a controller configured to control the support unit and the heating unit, and wherein when a treating position is divided into four equal parts from a first quadrant to a fourth quadrant based on a center of the mask, the laser irradiator is positioned at the fourth quadrant and the first quadrant in a direction linearly moving from a standby position to the treating position, positioned at the third quadrant in a direction which is perpendicular to the fourth quadrant, and positioned at the second quadrant in a direction which is perpendicular to the first quadrant, and wherein the controller controls a rotation of the support unit so the second pattern is positioned at the fourth quadrant.

A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, a photo catalytic layer disposed on the capping layer, and an absorber layer disposed on the photo catalytic layer and carrying circuit patterns having openings. Part of the photo catalytic layer is exposed at the openings of the absorber layer, and the photo catalytic layer includes one selected from the group consisting of titanium oxide (TiO.sub.2), tin oxide (SnO), zinc oxide (ZnO) and cadmium sulfide (CdS).

A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, a photo catalytic layer disposed on the capping layer, and an absorber layer disposed on the photo catalytic layer and carrying circuit patterns having openings. Part of the photo catalytic layer is exposed at the openings of the absorber layer, and the photo catalytic layer includes one selected from the group consisting of titanium oxide (TiO.sub.2), tin oxide (SnO), zinc oxide (ZnO) and cadmium sulfide (CdS).

A method involving determining an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model including a formula having a variable associated with a spatial property of the pattern or with an etch plasma species concentration of the etch step, and including a mathematical term including a natural exponential function to the power of a parameter that is fitted or based on an etch time of the etch step; and adjusting the patterning process based on the determined etch bias.

A method involving determining an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model including a formula having a variable associated with a spatial property of the pattern or with an etch plasma species concentration of the etch step, and including a mathematical term including a natural exponential function to the power of a parameter that is fitted or based on an etch time of the etch step; and adjusting the patterning process based on the determined etch bias.

A spin dry etching process includes loading an object into a dry etching system. A dry etching process is performed to the object, and the object is spun while the dry etching process is being performed. The spin dry etching process is performed using a semiconductor fabrication system. The semiconductor fabrication system includes a dry etching chamber in which a dry etching process is performed. A holder apparatus has a horizontally-facing slot that is configured for horizontal insertion of an etchable object therein. The etchable object includes either a photomask or a wafer. A controller is communicatively coupled to the holder apparatus and configured to spin the holder apparatus in a clockwise or counterclockwise direction while the dry etching process is being performed. An insertion of the etchable object into the horizontally-facing slot of the holder apparatus restricts a movement of the object as the dry etching process is performed.

A phase shift mask blank includes a transparent substrate, a phase shift layer, a first hard mask layer and an opaque layer. The transparent substrate is disposed on the transparent substrate. The first hard mask layer is disposed on the phase shift layer. The phase shift layer has an etching selectivity with respect to the first hard mask layer. The opaque layer is disposed on the first hard mask layer.