A method includes applying a first voltage to a source of a first transistor of a detector unit of a semiconductor detector in a test wafer and applying a second voltage to a gate of the first transistor and a drain of a second transistor of the detector unit. The first transistor is coupled to the second transistor in series, and the first voltage is higher than the second voltage. A pre-exposure reading operation is performed to the detector unit. Light of an exposure apparatus is illuminated to a gate of the second transistor after applying the first and second voltages. A post-exposure reading operation is performed to the detector unit. Data of the pre-exposure reading operation is compared with the post-exposure reading operation. An intensity of the light is adjusted based on the compared data of the pre-exposure reading operation and the post-exposure reading operation.

A lithography method in semiconductor fabrication is provided. The method includes generating multiple groups of small drops of a target material through a number of nozzles in such a way that small drops in each of the groups are aggregated to an elongated droplet of the target material. The method also includes generating a laser pulse from a laser generator to convert the elongated droplets to plasma which generates an EUV radiation. The method further includes exposing a semiconductor wafer to the EUV radiation.

A target supply device according to an aspect of the present disclosure includes a tank in which a target substance in a liquid form is housed, a vibration element configured to generate a droplet of the target substance by providing, through a vibration propagation path, vibration to the target substance output through the nozzle, a first temperature adjustment mechanism configured to adjust a temperature of a refrigerant to be supplied to the vibration propagation path component to a first temperature, a temperature sensor configured to detect a temperature of the vibration propagation path, a second temperature adjustment mechanism configured to adjust, to a second temperature, the temperature of the vibration propagation path to which the refrigerant is supplied, and a control unit configured to control the second temperature adjustment mechanism based on an output from the temperature sensor.

A droplet accelerating assembly includes an acceleration chamber extending in a first direction parallel to an ejection direction of the droplet, the acceleration chamber having a first side connected to the droplet generator, a second side opposite the first side in the first direction, the second side including a discharge hole, and a fluid flow path, a pressure controller connected to the fluid flow path of the acceleration chamber, the pressure controller being configured to adjust an internal pressure of the acceleration chamber, an electrifier in the acceleration chamber, the electrifier being configured to electrify the droplet ejected by the droplet generator into an electrified droplet, and an accelerator in the acceleration chamber, the accelerator being configured to accelerate the electrified droplet.

A method of controlling an extreme ultraviolet (EUV) lithography system is disclosed. The method includes irradiating a target droplet with EUV radiation, detecting EUV radiation reflected by the target droplet, determining aberration of the detected EUV radiation, determining a Zernike polynomial corresponding to the aberration, and performing a corrective action to reduce a shift in Zernike coefficients of the Zernike polynomial.

A lithography method in semiconductor fabrication is provided. The method includes generating a plurality of drops of a target material through a plurality of nozzles, adjacent two of the plurality of nozzles having a distance less than a width of a first one of the adjacent two of the plurality of nozzles, wherein the plurality of drops are aggregated to an elongated droplet; generating a laser pulse to convert the elongated droplet into plasma that generates an extreme ultraviolet (EUV) radiation; exposing a semiconductor substrate to the EUV radiation.

A target image capturing device according to an aspect of the present disclosure includes a delay circuit configured to receive a timing signal from outside and output a first trigger signal at a timing delayed by a first delay time from the reception of the timing signal; an illumination light source configured to emit light based on the first trigger signal; an image capturing unit including a light amplification unit and disposed to capture an image of a shadow of a target to be observed, which is generated when the target is irradiated with the light emitted from the illumination light source; a processing unit configured to perform image processing including processing of measuring a background luminance from the image captured by the image capturing unit; and a control unit configured to perform control to adjust a gain of the light amplification unit based on the background luminance.

In one embodiment, a writing data generating method is for generating writing data used in a multi charged particle beam writing apparatus. The method includes calculating, for a figure containing a curve and a straight line included in design data, a plurality of control points representing the curve and a plurality of vertices of the curve and straight line, and expressing a position of each of the control points and vertices as a displacement from an adjacent control point or vertex to generate the writing data.

The present invention relates to a stage system (130), which comprises a pre-exposure element (134), and to a method employing the pre-exposure element for conditioning an optical system (100). The pre-exposure element comprises a radiation receiving area at a surface of the stage system, wherein the radiation receiving area comprises at least one pre-exposure plate configured to receive radiation. The stage system comprises further a controller (140), wherein the controller is capable to control an optical parameter of the pre-exposure element, herewith controlling a portion of received radiation reflected by the pre-exposure element.

A method of manufacturing a photomask including the steps of receiving initial photomask design data associated with one or more patterns to be formed on a photomask and optimizing the initial photomask design data to minimize printing exposure energy while maintaining an acceptable pattern quality and size. In embodiments, the step of optimizing includes setting minimization of printing exposure energy as a priority design rule, setting optimization of pattern quality and size as a secondary design rule, iterating size of mask design features to determine a range of size biases that satisfy both the priority and secondary design rules so as to provide an initial optimized mask design, and adjusting mask variables over the range of size biases to determine mask variables that further optimize the initial optimized mask design to obtain a final optimized mask design.