Abstract: A photomask mask assembly includes a reflective photomask and a protection structure. The reflective photomask includes a substrate and a reflective multilayer on a first substrate surface of the substrate at a front side of the reflective photomask. The protection structure is on a second substrate surface of the substrate at a backside of the reflective photomask, and is detachable from the reflective photomask at a temperature below 150 degree Celsius.

Abstract: A reflective photomask includes a substrate with a substrate layer of a low thermal expansion material. The substrate layer includes a main portion of a first structural configuration and an auxiliary portion of a second structural configuration of the low thermal expansion material. The auxiliary portion is formed in a frame section surrounding a pattern section of the substrate. A multilayer mirror is formed on a first surface of the substrate. A reflectivity of the multilayer mirror is at least 50% at an exposure wavelength below 15 nm. A frame trench extending through the multilayer mirror exposes the substrate in the frame section. The auxiliary portion may include scatter centers for out-of-band radiation.

Abstract: A reflective photomask includes a substrate with a substrate layer of a low thermal expansion material. The substrate layer includes a main portion of a first structural configuration and an auxiliary portion of a second structural configuration of the low thermal expansion material. The auxiliary portion is formed in a frame section surrounding a pattern section of the substrate. A multilayer mirror is formed on a first surface of the substrate. A reflectivity of the multilayer mirror is at least 50% at an exposure wavelength below 15 nm. A frame trench extending through the multilayer mirror exposes the substrate in the frame section. The auxiliary portion may include scatter centres for out-of-band radiation.

Abstract: A method of manufacturing a photomask includes forming a mask pattern with a critical mask feature on a photomask. Shape information which is descriptive for an outline of the critical mask feature is obtained from the photomask. The shape information contains position information identifying the positions of landmarks on the outline relative to each other. The landmarks may indicate local curvature extrema, points of inflexion, sharp bends in the curvature and/or local curvature-change maxima in the outline of the mask feature, respectively. The shape information may enable a shape metrology which is not completely based on rectangular approximations of mask features.

Abstract: A method of manufacturing a photomask includes forming a mask pattern with a critical mask feature on a photomask. Shape information which is descriptive for an outline of the critical mask feature is obtained from the photomask. The shape information contains position information identifying the positions of landmarks on the outline relative to each other. The landmarks may indicate local curvature extrema, points of inflexion, sharp bends in the curvature and/or local curvature-change maxima in the outline of the mask feature, respectively. The shape information may enable a shape metrology which is not completely based on rectangular approximations of mask features.

Abstract: An EUV mask set and method of manufacturing is disclosed. In one embodiment, a set of EUV mask blanks is inspected to obtain information about defects in each of the EUV mask blanks. From the obtained information, a set of complementary functional portions is determined, wherein each functional portion is assigned to one of the EUV mask blanks and does not contain any of the defects. The functional portions of the EUV mask blanks of the EUV mask blank set complement one another to form a virtual image area corresponding in size to image areas of the EUV mask blanks. A predefined mask pattern is provided on the EUV mask blanks. Information identifying position and shape of the functional portions is used to control an illumination process for imaging the predefined mask pattern onto a target.

Abstract: An EUV mask set and method of manufacturing is disclosed. In one embodiment, a set of EUV mask blanks is inspected to obtain information about defects in each of the EUV mask blanks. From the obtained information, a set of complementary functional portions is determined, wherein each functional portion is assigned to one of the EUV mask blanks and does not contain any of the defects. The functional portions of the EUV mask blanks of the EUV mask blank set complement one another to form a virtual image area corresponding in size to image areas of the EUV mask blanks. A predefined mask pattern is provided on the EUV mask blanks. Information identifying position and shape of the functional portions is used to control an illumination process for imaging the predefined mask pattern onto a target.

Abstract: A lithographic mask comprises a first layer including grooves, a second layer including regions, sections and a groove-like structure that encloses the sections. The first and second layers are formed so as to reduce electrical potential differences within the second layer. A method of forming a lithographic mask includes forming first and second layers to dispose the second layer over the first layer, patterning the second layer to comprise sections, a region, and a groove-like structure enclosing the sections, and forming grooves in the first layer at portions not covered by the second layer. The first and second layers are formed to reduce potential differences within the second layers during the step of forming the grooves in the first layer.

Abstract: A first exposure dose for a shot area based upon layout data is determined. A correction dose compensating a dose deviation between a first point in time, at which a control unit configured to control a shot time period of a particle beam writing apparatus considers a charged particle beam as having reached a nominal current density, and a second point in time, at which the charged particle beam has actually reached a nominal current density, at a target substrate is determined.

Abstract: An EUV mask comprises a substrate, a reflective multilayer on the substrate, a phase-shifting material disposed above the multilayer in at least one first portion of the substrate, and a masking material disposed above the multilayer in second portions of the substrate and corresponding to mask patterns of an EUV mask. There is also provided a method for repairing an EUV mask including a substrate, a reflective multilayer on the substrate and at least one defect beneath or within the multilayer. The method includes the steps of determining the position of a defect area of the substrate, in which a phase-shift difference of an exposure radiation is caused by the defect, and depositing a phase-shifting material above the multilayer in at least one first portion of the substrate, the first portion at least partially comprising the defect area.

Abstract: Methods for producing a photomask or layer or stack patterning include applying two resists to a layer, a layer stack, or a mask substrate (collectively “the layer”). Sensitivity of the first resist with respect to the exposure dose is greater than sensitivity of the second. Both resists are subjected to an exposure dose in defined regions of the layer surface, the dose varying locally between first and second doses. The first dose is chosen to expose the first resist but not the second. The second dose is chosen to expose the second resist. After a first development of the second and of the first resist the layer is etched at the uncovered locations for a first time. After complete removal of the second resist and a second development of the first resist, the layer is etched. As a result, it is possible to produce structures of different depths in the layer.

Abstract: A method of determining an exposure dose for writing a pattern using an electron beam writer determines a target dose in the exposure region to obtain a predetermined energy deposition in a specific position of the exposure region, the predetermined energy deposition being larger than a reference energy deposition in the non-exposure region. The target dose is locally increased in a marginal region of the exposure region (the marginal region being adjacent the exposure boundary) to a value that obtains an energy deposition in the marginal region higher than the predetermined energy deposition. Optionally, the target dose can be locally decreased in an intermediate region of the exposure region (the intermediate region being adjacent the marginal region) to a value that obtains an energy deposition in the intermediate region smaller than the predetermined energy deposition. Also provided is an exposure device for carrying out the method.

Abstract: A method of cleaning a surface of a photomask by removing contaminants from its surface that includes placing the photomask in a vessel, which is held under an elevated pressure and feeding a supercritical fluid, in particular, CO2 in a supercritical state, to the vessel. An additive, such as alcohol, water ketones, esters, surfactants, and organic solvents, can be added to the fluid. The vessel can be held under a pressure higher than the critical pressure of the fluid and at a temperature higher than the critical temperature of the fluid.

Abstract: A first exposure dose for a shot area based upon layout data is determined. A correction dose compensating a dose deviation between a first point in time, at which a control unit configured to control a shot time period of a particle beam writing apparatus considers a charged particle beam as having reached a nominal current density, and a second point in time, at which the charged particle beam has actually reached a nominal current density, at a target substrate is determined.

Abstract: An EUV mask comprises a substrate, a reflective multilayer on the substrate, a phase-shifting material disposed above the multilayer in at least one first portion of the substrate, and a masking material disposed above the multilayer in second portions of the substrate and corresponding to mask patterns of an EUV mask. There is also provided a method for repairing an EUV mask including a substrate, a reflective multilayer on the substrate and at least one defect beneath or within the multilayer. The method includes the steps of determining the position of a defect area of the substrate, in which a phase-shift difference of an exposure radiation is caused by the defect, and depositing a phase-shifting material above the multilayer in at least one first portion of the substrate, the first portion at least partially comprising the defect area.

Abstract: Mask blanks of the invention include an absorber layer, an anti-reflective layer disposed over the absorber layer, and a hard mask layer disposed over the anti-reflective layer. The absorber layer is absorbent at an exposure wavelength and is reflective at an inspection wavelength. The inspection wavelength is greater than or equal to the exposure wavelength. The anti-reflective layer is not reflective at the inspection wavelength. None of the main constituents of the hard mask layer has an atomic number greater than 41. The mask blank may be a reflective EUVL mask blank or a transparent mask blank.

Abstract: Methods for producing a photomask or layer or stack patterning include applying two resists to a layer, a layer stack, or a mask substrate (collectively “the layer”). Sensitivity of the first resist with respect to the exposure dose is greater than sensitivity of the second. Both resists are subjected to an exposure dose in defined regions of the layer surface, the dose varying locally between first and second doses. The first dose is chosen to expose the first resist but not the second. The second dose is chosen to expose the second resist. After a first development of the second and of the first resist the layer is etched at the uncovered locations for a first time. After complete removal of the second resist and a second development of the first resist, the layer is etched. As a result, it is possible to produce structures of different depths in the layer.

Abstract: A test pattern or set of patterns, a method of evaluating the transfer properties of the pattern, and a method of determining a parameter of a transfer process (e.g., imaging process) making use of the test pattern is provided. With the test pattern, the impact of line edge roughness on a transferred pattern may be analyzed. For example, the test pattern may be based upon a lines/spaces pattern, wherein periodic structures having a well-defined period and amplitude are adjacent to the lines. A photomask is provided with the test pattern and an image of the pattern is obtained. Edges of the image are determined and, therefrom, a set of edge position data are obtained. Edge position data are fitted to a straight line to determine edge position residuals. An amplitude spectrum is calculated dependent upon spatial frequencies to obtain a amplitude/spatial frequency relationship. A ratio of determined maximum is formed.

Abstract: A method of cleaning a substrate surface from a crystal nucleus in which the substrate surface is held in a condition under which a crystal growth is accelerated with respect to normal clean room and normal air conditions. In particular, light having a wavelength to induce a crystal growth is irradiated and, additionally, at least one reactive gas is fed at a higher concentration than under normal clean room and normal air conditions. After placing the substrate under these conditions, the grown crystals are removed, for example, by rinsing with water. As a consequence, the crystal nucleus is removed from the substrate surface.