摘要:
Movements of a lithographic apparatus include dynamic positioning errors on one or more axes which cause corresponding errors which can be measured in the applied pattern. A test method includes operating the apparatus several times while deliberately imposing a relatively large dynamic positioning error at different specific frequencies and axes. Variations in the error in the applied pattern are measured for different frequencies and amplitudes of the injected error across a frequency band of interest for a given axis or axes. Calculation using said measurements and knowledge of the frequencies injected allows analysis of dynamic positioning error variations in frequency bands correlated with each injected error frequency.
摘要:
Movements of a lithographic apparatus include dynamic positioning errors on one or more axes which cause corresponding errors which can be measured in the applied pattern. A test method includes operating the apparatus several times while deliberately imposing a relatively large dynamic positioning error at different specific frequencies and axes. Variations in the error in the applied pattern are measured for different frequencies and amplitudes of the injected error across a frequency band of interest for a given axis or axes. Calculation using said measurements and knowledge of the frequencies injected allows analysis of dynamic positioning error variations in frequency bands correlated with each injected error frequency.
摘要:
A method of measuring a lithographic projection apparatus is described. The method includes imaging a verification mark of a patterning device onto a radiation-sensitive layer held by a substrate table of a lithographic apparatus, wherein the verification mark includes at least a first, a second and a third verification structure that have a mutually different sensitivity profile for a dose setting, a focus setting and a contrast setting.
摘要:
A method of measuring a lithographic projection apparatus is described. The method includes imaging a verification mark of a patterning device onto a radiation-sensitive layer held by a substrate table of a lithographic apparatus, wherein the verification mark includes at least a first, a second and a third verification structure that have a mutually different sensitivity profile for a dose setting, a focus setting and a contrast setting.
摘要:
A method of measuring focus of a lithographic projection apparatus includes exposure of a photoresist covered test substrate with a plurality of verification fields. Each of the verification fields includes a plurality of verification markers, and the verification fields are exposed using a predetermined focus offset. After developing, an alignment offset for each of the verification markers is measured and translated into defocus data using a transposed focal curve.
摘要:
A method of measuring focus of a lithographic projection apparatus includes exposure of a photoresist covered test substrate with a plurality of verification fields. Each of the verification fields includes a plurality of verification markers, and the verification fields are exposed using a predetermined focus offset FO. After developing, an alignment offset for each of the verification markers is measured and translated into defocus data using a transposed focal curve. The method according to an embodiment of the invention may result in a focus-versus alignment shift sensitivity up to 50 times higher (typically dX,Y/dZ=20) than conventional approaches.
摘要:
A method of calibrating an inspection apparatus. Obtaining a surface level measurements (LS) at respective level sensing locations LS(x,y). Determining focus settings (LPA, LPB) for exposure field regions (EFA, EFB) in accordance with surface level measurements (LSA, LSB) having level sensing locations corresponding to the respective exposure field region. Exposing exposure field regions (EFA, EFB) with focus offsets (FO1, FO2) defined with reference to the respective focus settings (LPA, LPB) to produce target patterns at respective target locations. Obtaining focus-dependent property measurements, such as Critical Dimension (CD) and/or side wall angle (SWA) of the target patterns measured using the inspection apparatus; and calibrating the inspection apparatus using the focus-dependent property measurements (CD/SWA) and the respective focus offsets (FO1, FO2). The calibration uses surface level measurements (e.g., LSB(3)) having a level sensing location (e.g., LSLB(3)) corresponding to the respective target location (TLB). Each offset value is thus corrected in the calibration for the local wafer stack unflatness present during exposure.
摘要:
A method of calibrating an inspection apparatus. Obtaining a surface level measurements (LS) at respective level sensing locations LS(x,y). Determining focus settings (LPA, LPB) for exposure field regions (EFA, EFB) in accordance with surface level measurements (LSA, LSB) having level sensing locations corresponding to the respective exposure field region. Exposing exposure field regions (EFA, EFB) with focus offsets (FO1, FO2) defined with reference to the respective focus settings (LPA, LPB) to produce target patterns at respective target locations. Obtaining focus-dependent property measurements, such as Critical Dimension (CD) and/or side wall angle (SWA) of the target patterns measured using the inspection apparatus; and calibrating the inspection apparatus using the focus-dependent property measurements (CD/SWA) and the respective focus offsets (FO1, FO2). The calibration uses surface level measurements (e.g., LSB(3)) having a level sensing location (e.g., LSLB(3)) corresponding to the respective target location (TLB). Each offset value is thus corrected in the calibration for the local wafer stack unflatness present during exposure.
摘要:
A method of measuring focus of a lithographic projection apparatus includes exposure of a photoresist covered test substrate with a plurality of verification fields. Each of the verification fields includes a plurality of verification markers, and the verification fields are exposed using a predetermined focus offset. After developing, an alignment offset for each of the verification markers is measured and translated into defocus data using a transposed focal curve.
摘要:
Calibration of spot height offsets in a level sensor is performed on a resist-coated substrate to eliminate process dependencies of substrate position measurements obtained by the level sensor.