Method of measuring a height profile of one or more substrates is provided comprising measuring a first height profile of one or more fields on a substrate using a first sensor arrangement, the first height profile being the sum of a first interfield part and a first intrafield part, measuring a second height profile of one or more further fields on the substrate or on a further substrate using a second sensor arrangement, the second height profile being the sum of a second interfield part and a second intrafield part, determining from the measurements with the first sensor arrangement an average first intrafield part, and determining the height profile of the further fields from the second interfield part and the average first intrafield part thereby correcting the measurements of the second sensor arrangement.

Systems and methods that include providing for measuring a first topographical height of a substrate at a first coordinate on the substrate and measuring a second topographical height of the substrate at a second coordinate on the substrate are provided. The measured first and second topographical heights may be provided as a wafer map. An exposure process is then performed on the substrate using the wafer map. The exposure process can include using a first focal point when exposing the first coordinate on the substrate and using a second focal plane when exposing the second coordinate on the substrate. The first focal point is determined using the first topographical height and the second focal point is determined using the second topographical height.

A gas gauge proximity sensor comprising a measurement gas flow channel having an optical pressure sensor for comparing a pressure of the first gas flow and a reference pressure; the optical pressure sensor comprising a first optical cavity fluidly connected to the measurement channel and a second optical cavity fluidly connected to the reference pressure, with the optical cavities being configured to receive electromagnetic radiation and output reflected electromagnetic radiation, the optical pressure sensor further being configured to combine the reflected electromagnetic radiation from the first optical cavity with the reflected electromagnetic radiation from the second optical cavity and determine, based on the combined electromagnetic radiation, a pressure difference between the pressure of the first gas flow and the reference pressure and determine, based on the pressure difference, a distance between the measurement outlet and the measurement object.

A lens anti-contamination device is disclosed, including a first device (300) and a second device (400) connected to the first device (300), the first device (300) being closer to a lens (100) relative to the second device (400), wherein the first device (300) is used to output protective layer gas, and the protective layer gas is enabled to uniformly flow in close contact with the lower surface of the lens (100) through a nozzle (330), such that the contaminated lens (100) can be cleaned and a protective layer is funned to prevent the lens from being contaminated again; the second device (400) is used to take away gas close to a contamination source, and the contamination gas enters an annular cavity (420) through small holes (410) and is exhausted into a distant environment through the suction and exhaust power of an exhaust passage (200). A lens anti-contamination method is also disclosed. Before exposure, the first device (300) is turned on and then the second device (400) is turned on; and after 12 hours after exposure, the second device (400) may be turned off. This device and method can better solve the problem that organic matters in photoresist are volatilized and contaminate the lens, it is simple to mount, the service life is long, the cost is low, the reliability is high, and it guarantees that contaminants are fully removed without entering the object lens.

A lithographic apparatus uses a height sensor to obtain height sensor data representing a topographical variation across a substrate. The height sensor data is used to control focusing of a device pattern at multiple locations across the substrate. A controller identifies one or more first areas where height sensor data is judged to be reliable and one or more second areas where the height sensor data is judged to be less reliable. Substitute height data is calculated for the second areas using height sensor data for the first areas together with prior knowledge of expected device-specific topography. The focusing of the lithographic apparatus is controlled using a combination of the height data from the sensor and the substitute height data.

Described are a method for processing a surface of an object, in particular of a lithographic mask, an apparatus for carrying out such a method and a computer program containing instructions for carrying out such a method.

A method for processing a surface of an object, in particular of a lithographic mask, includes the following steps: (a.) supplying a gas mixture containing at least a first gas and a second gas to a reaction site at the surface of the object; (b.) inducing a reaction, which includes at least a first partial reaction and a second partial reaction, at the reaction site by exposing the reaction site to a beam of energetic particles in a plurality of exposure intervals, wherein the first partial reaction is promoted primarily by the first gas and the second partial reaction is promoted primarily by the second gas, and wherein a gas refresh interval lies between the respective exposure intervals; (c.) setting a first time duration for the gas refresh interval, as a result of which the process rate of the first partial reaction and the process rate of the second partial reaction are present; (d.) setting a second time duration for the gas refresh interval, which brings about a relative increase in the process rate of the first partial reaction in comparison with the process rate of the second partial reaction.

An apparatus, such as a lithographic apparatus, has a metrology frame that has a reference frame mounted thereon that includes a reference surface. A gas gauge is movable relative to the reference frame, metrology frame, and a measured surface. A reference nozzle in the gas gauge provides gas to the reference surface and a measurement nozzle provides gas to the measured surface. A microelectromechanical (MEM) sensor may be used with the gas gauge to sense a difference in backpressure from each of the reference nozzle and the measurement nozzle. Optionally, multiple gas gauges are positioned in an array, which may extend in a direction that is substantially parallel to a plane of the measured surface. The gauges may be fluidly connected to a reference nozzle of the gas gauge. A channel may distribute gas across the array.

Method of measuring a height profile of one or more substrates is provided comprising measuring a first height profile of one or more fields on a substrate using a first sensor arrangement, the first height profile being the sum of a first interfield part and a first intrafield part, measuring a second height profile of one or more further fields on the substrate or on a further substrate using a second sensor arrangement, the second height profile being the sum of a second interfield part and a second intrafield part, determining from the measurements with the first sensor arrangement an average first intrafield part, and determining the height profile of the further fields from the second interfield part and the average first intrafield part thereby correcting the measurements of the second sensor arrangement.

Systems and methods that include providing for measuring a first topographical height of a substrate at a first coordinate on the substrate and measuring a second topographical height of the substrate at a second coordinate on the substrate are provided. The measured first and second topographical heights may be provided as a wafer map. An exposure process is then performed on the substrate using the wafer map. The exposure process can include using a first focal point when exposing the first coordinate on the substrate and using a second focal plane when exposing the second coordinate on the substrate. The first focal point is determined using the first topographical height and the second focal point is determined using the second topographical height.

A lens anti-contamination device is disclosed, including a first device (300) and a second device (400) connected to the first device (300), the first device (300) being closer to a lens (100) relative to the second device (400), wherein the first device (300) is used to output protective layer gas, and the protective layer gas is enabled to uniformly flow in close contact with the lower surface of the lens (100) through a nozzle (330), such that the contaminated lens (100) can be cleaned and a protective layer is funned to prevent the lens from being contaminated again; the second device (400) is used to take away gas close to a contamination source, and the contamination gas enters an annular cavity (420) through small holes (410) and is exhausted into a distant environment through the suction and exhaust power of an exhaust passage (200). A lens anti-contamination method is also disclosed. Before exposure, the first device (300) is turned on and then the second device (400) is turned on; and after 12 hours after exposure, the second device (400) may be turned off. This device and method can better solve the problem that organic matters in photoresist are volatilized and contaminate the lens, it is simple to mount, the service life is long, the cost is low, the reliability is high, and it guarantees that contaminants are fully removed without entering the object lens.