摘要:
An electron beam apparatus focusses an electron beam onto a specimen by means of an objective magnetic lens. In order to detect changes in the height of the specimen, a laser light beam from a laser source is incident on the specimen and the reflected laser beam is detected by a light detector. Any change in the height of the specimen changes the path of the laser beam to the detector. Therefore, by monitoring the detector, the focussing of the electron beam on the specimen can be controlled by varying the current to an excitation coil of the objective magnetic lens or by moving the specimen via a mounting stage. At least one of the pole pieces of the objective lens is on the opposite side of the path of the laser beam to the source of the electron beam, so that the objective magnetic lens may be close to the specimen, permitting a short focal length. Thus, the laser beam may pass between the pole pieces. An optical microscope may also be provided to permit the specimen to be viewed. The viewing path of the optical microscope extends through an opening in one or both of the pole pieces of the objective magnetic lens.
摘要:
An electron beam is focused on a specimen by a focusing lens. A light beam is incident on the position of irradiation of the specimen with the electron beam and the reflected light beam is detected by a linear light detector. The output of the detector is used to measure the height of the specimen at the position of irradiation of the electron beam. The specimen is moved in a plane perpendicular to an optical axis of the focusing lens. A specimen height measuring device carries out the height measurement of the specimen at a position to be observed on the specimen and at positions thereon which are in the vicinity of the position to be observed, when those positions are located at the position of irradiation of the electron beam. The specimen height measuring device averages the measured values so as to produce a focusing correction signal on the basis thereof and controls the focusing lens on the basis of the focusing correction signal.
摘要:
The present invention aims to provide an axis alignment method, astigmatism correction method and SEM for implementing these methods, which can prevent an alignment or correction error attributable to conditions of a specimen. A first aspect is to obtain the difference between the optimal values acquired from an automatic axis alignment result on a standard sample and from each of automatic axis alignment results on a observation target sample, and to correct an optimal value adjusted using the standard sample by use of the difference thus obtained. A second aspect is to acquire an optimal stigmator value (astigmatism correction signal) by using the standard sample, to store the optimal stigmator value as a default value, to add the optimal stigmator value and the default value depending on the height of an observation target sample pattern, and to perform an astigmatism correction on the basis of the resultant stigmator value.
摘要:
A method and apparatus for alignment and astigmatism correction for a scanning electron microscope can prevent an alignment or correction error attributable to the conditions of a particular specimen. First, a difference is determined between optimal values acquired from an automatic axis alignment result on a standard sample, and those obtained from each of a plurality automatic axis alignment results on a observation target sample. An optimal value is then adjusted using the standard sample, by use of the difference thus obtained. Correspondingly, an optimal stigmator value (astigmatism correction signal) is acquired by using the standard sample, and storing the optimal stigmator value as a default value. The optimal stigmator value and the default value depending on the height of an observation target sample pattern are added, and an astigmatism correction is performed on the basis of the resultant stigmator value.
摘要:
Beforehand, the device characteristic patterns of each critical dimension SEM are measured, a sectional shape of an object to undergo dimension measurement is presumed by a model base library (MBL) matching system, dimension measurements are carried out by generating signal waveforms through SEM simulation by inputting the presumed sectional shapes and the device characteristic parameters, and differences in the dimension measurement results are registered as machine differences. In actual measurements, from the dimension measurement results in each critical dimension SEM, machine differences are corrected by subtracting the registered machine differences. Furthermore, changes in critical dimension SEM's over time are monitored by periodically measuring the above-mentioned device characteristic parameters and predicting the above-mentioned dimension measurement results. According to the present invention, actual measurements of machine differences, which require considerable time and effort, are unnecessary. In addition, the influence of changes in samples over time, which is problematic in monitoring changes in devices over time, can be eliminated.
摘要:
A sample measuring method and a charged particle beam apparatus are provided which remove contaminants, that have adhered to a sample in a sample chamber of an electron microscope, to eliminate adverse effects on the subsequent manufacturing processes. To achieve this objective, after the sample measurement or inspection is made by using a charged particle beam, contaminants on the sample are removed before the next semiconductor manufacturing process. This allows the contaminants adhering to the sample in the sample chamber to be removed and therefore failures or defects that may occur in a semiconductor fabrication process following the measurement and inspection can be minimized.
摘要:
A method and a device are disclosed for suppressing error in electrostatic charge amount or defocus on the basis of electrostatic charge storage due to electron beam scanning when measuring the electrostatic charge amount of the sample or a focus adjustment amount by scanning the electron beam. An electrostatic charge measurement method, a focus adjustment method, or a scanning electron microscope for measuring an electrostatic charge amount or controlling an application voltage to the sample changes the application voltage to the energy filter while moving the scanning location of the electron beam on the sample.
摘要:
A structure of an electron beam apparatus having shielding properties for shielding against an environmental magnetic field is provided. The electron beam apparatus comprises a mirror barrel for housing a magnetic lens for converging an electron beam onto a specimen and a specimen chamber for housing the specimen, wherein a non-magnetic material having conductivity is used as a material for at least one of the mirror barrel and a main body of the specimen chamber. The material for the mirror barrel or the main body of the specimen chamber is an aluminum alloy and a thickness of a sidewall of the mirror barrel or the main body of the specimen chamber is 10 mm or more. A magnetic plate having a thickness smaller than that of the sidewall of the mirror barrel or the main body of the specimen chamber is provided on an inner sidewall of the mirror barrel or the main body of the specimen chamber.
摘要:
A structure of an electron beam apparatus having shielding properties for shielding against an environmental magnetic field is provided. The electron beam apparatus comprises a mirror barrel for housing a magnetic lens for converging an electron beam onto a specimen and a specimen chamber for housing the specimen, wherein a non-magnetic material having conductivity is used as a material for at least one of the mirror barrel and a main body of the specimen chamber. The material for the mirror barrel or the main body of the specimen chamber is an aluminum alloy and a thickness of a sidewall of the mirror barrel or the main body of the specimen chamber is 10 mm or more. A magnetic plate having a thickness smaller than that of the sidewall of the mirror barrel or the main body of the specimen chamber is provided on an inner sidewall of the mirror barrel or the main body of the specimen chamber.
摘要:
A method for recognizing a three-dimensional objective in which a two-dimensional image is obtained from the same viewing point as a distance image obtained by picking up the objective in a three-dimensional space and the two-dimensional image is utilized to previously limit an existence zone of the objective under detection for the distance image and to perform objective detecting operation over the partial distance image in the limited zone, thereby realizing a sufficiently high speed detection of, in particular, the three-dimensional objective.