There is provided a method and system for diagnosing a condition of an aircraft engine. The method comprises obtaining a sample of lubricating fluid from the engine, filtering the sample to obtain a plurality of particles from the lubricating fluid, directing an excitation beam towards the particles, detecting an energy level emitted from the particles in response to the excitation beam, determining a level of coking in the lubricating fluid based on a difference between the energy level as detected and an expected energy level, and diagnosing a condition of the engine based on the level of coking in the lubricating fluid.

There is provided a method, a non-transitory computer readable medium, and a system for measuring a pattern. The method can include (a) obtaining an electron image of an area of a sample, the area comprises the pattern, the electron image comprises multiple lines; each line comprises information obtained by moving an electron beam over a scan line; (b) generating a converted image by applying a noise reduction kernel on the electron image, the noise reduction kernel has a width that represents a number of consecutive lines of the electron image; the width is determined based on relationships between analysis results obtained when using noise reduction kernels of different widths; and (c) analyzing the converted image to provide a pattern measurement.

A defect characterization method includes: a first scanning image and target defect coordinates in the first scanning image are obtained; a first defect image is obtained according to the target defect coordinates in the first scanning image, the first defect image containing a defect area where a target defect is located and a noise area not containing the target defect; the noise area is marked, Automatic Defect Review (ADR) calculation is performed on the defect area, and a pixel level value of a defect in the defect area is obtained; coordinates of the defect with a maximum pixel level value are obtained, and a second defect image is obtained according to the coordinates of the defect with the maximum pixel level value; and the defect with the maximum pixel level value is classified according to the second defect image.

A computing unit generates a to-be-used-in-computation netlist on the basis of a to-be-used-in-calculation device model corresponding to a correction sample, estimates a first application result, on the basis of the to-be-used-in-computation netlist and an optical condition, when a charged particle beam is applied to the correction sample under the optical condition, compares the first application result and a second application result based on a detection signal when the charged particle beam is applied to the correction sample under the optical condition, and corrects the optical condition when the first application result and the second application result differ from each other.

There is provided a method, a non-transitory computer readable medium, and a system for measuring a pattern. The method can include (a) obtaining an electron image of an area of a sample, the area comprises the pattern, the electron image comprises multiple lines; each line comprises information obtained by moving an electron beam over a scan line; (b) generating a converted image by applying a noise reduction kernel on the electron image, the noise reduction kernel has a width that represents a number of consecutive lines of the electron image; the width is determined based on relationships between analysis results obtained when using noise reduction kernels of different widths; and (c) analyzing the converted image to provide a pattern measurement.

A method for measuring secondary electron emission coefficient comprising: providing a device including a first collecting plate and a second collecting plate, and measuring an injection current. Short-circuiting the first collecting plate and the second collecting plate; placing a sample and applying a 50 volt positive voltage between the sample and the first collecting plate, I.sub.SE is 0; measuring a current I.sub.1 between the sample and the first collecting plate, and ignoring I.sub.BG1; and according to formula I.sub.1=I.sub.BG1+I.sub.others+I.sub.SE, obtaining a current of other electrons. Applying a positive voltage between the first collecting plate and the sample; measuring a current I.sub.2 between the first collecting plate and the sample, and ignoring I.sub.BG2; and obtaining I.sub.SE formed by the secondary electrons according to formula I.sub.2=I.sub.BG2+I.sub.others+I.sub.SE. Obtaining the secondary electron emission coefficient according to formula $\delta =\frac{I_{\mathrm{SE}}}{I_{\mathrm{injection}\mathrm{current}}}.$

A device for measuring a secondary electron emission coefficient comprises a scanning electron microscope, a first collecting plate, a second collecting plate, a first galvanometer, a second galvanometer, a voltmeter, and a Faraday cup. The scanning electron microscope comprises an electron emitter and a chamber. A sample is located between the first collecting plate and the second collecting plate. The first galvanometer is used to test a current intensity of electrons escaping from the sample and hitting the first collecting plate and the second collecting plate. A high-energy electron beam emitted by the electron emitter passes through the first collecting plate and the second collecting plate, and enters the Faraday cup. The second galvanometer is used to test a current intensity of electrons entering the Faraday cup.

A method of evaluating a region of a sample that includes a plurality of holes, wherein the method includes: taking a first image of the region by scanning the region with a first charged particle beam; evaluating the first image to determine a first center-to-center distance between first and second holes in the plurality of holes; milling a diagonal cut in an area within the region that includes the second hole at an angle such that an upper surface of the sample in the milled area where the second hole is located is recessed with respect to an upper surface of the sample where the first hole is located; thereafter, taking a second image of the region by scanning the region with the first charged particle beam; evaluating the second image to determine a second center-to-center distance between first and second holes in the plurality of holes; and comparing the second center-to-center distance to the first center-to-center distance.

The invention relates to a method of, and apparatus for, examining a sample using a charged particle beam apparatus. The method as defined herein comprises the step of detecting, using a first detector, emissions of a first type from the sample in response to the charged particle beam illuminating the sample. The method further comprises the step of acquiring spectral information on emissions of a second type from the sample in response to the charged particle beam illuminating the sample. As defined herein, said step of acquiring spectral information comprises the steps of providing a spectral information prediction algorithm and using said algorithm for predicting said spectral information based on detected emissions of the first type as an input parameter of said algorithm. With this it is possible to gather EDS data using only a BSE detector.

According to one or more embodiments, a method of growing crystals on a QCM sensor may include treating a crystal growth surface of the QCM sensor with a coupling agent, applying a cation stream to the crystal growth surface of the QCM sensor, and applying an anion stream to the crystal growth surface of the QCM sensor. The crystals forming a crystal layer may have an average thickness greater than 5 nanometers. According to one or more embodiments, a QCM sensor may include a crystal layer on a crystal growth surface of the QCM sensor, where the crystal layer is formed by a process including treating the crystal growth surface of the QCM sensor with a coupling agent, applying a cation stream to the crystal growth surface of the QCM sensor, and applying an anion stream to the crystal growth surface of the QCM sensor.