JP4230899B2 - Circuit pattern inspection method - Google Patents

Description

The present invention relates to a pattern inspection technique for a semiconductor device or a photomask, relates to a novel circuit pattern inspection how to compare test using an electron beam.

  As a method for inspecting defects existing in a pattern on a semiconductor wafer, a defect inspection apparatus that irradiates a semiconductor wafer with white light and compares the same kind of circuit patterns of a plurality of LSIs using an optical image has been put into practical use. . An outline of the inspection method is described in Non-Patent Document 1.

  When a semiconductor wafer in the manufacturing process was inspected by such an optical inspection method, residues and defects could not be detected in a pattern having a silicon oxide film or a photosensitive photoresist material on the surface through which light was transmitted. . Moreover, the etching residue which is below the resolution of the optical system and the non-opening defect of the minute conduction hole could not be detected. Furthermore, a defect generated at the bottom of the step of the wiring pattern could not be detected.

  In recent years, with the miniaturization of circuit patterns, the complexity of circuit pattern shapes, and the diversification of materials, it has become difficult to detect defects using optical images, so circuit patterns can be created using electron beam images with higher resolution than optical images. A comparative inspection method has been proposed. When a circuit pattern is comparatively inspected with an electron beam image, in order to obtain a practical inspection time, an image is acquired at a very high speed compared to observation with a scanning electron microscope (hereinafter referred to as SEM). There is a need. And it is necessary to ensure the resolution of the image acquired at high speed and the SN ratio of the image.

  Patent Document 1 is known as a pattern comparison inspection apparatus using an electron beam. For these, a conductive substrate is irradiated with an electron beam having an electron beam current 100 times or more (10 nA or more) of a normal SEM, and any of secondary electrons, reflected electrons, and transmitted electrons is detected, and the signal is detected. An automatic defect detection method for comparing and inspecting an image formed from the above is disclosed.

  Patent Document 2 is known as a method for inspecting or observing a circuit board having an insulator with an electron beam. In order to reduce the influence of charging, a method of acquiring a stable image by low-acceleration electron beam irradiation of 2 keV or less is disclosed.

  A high current and low acceleration electron beam makes it difficult to obtain a high resolution image due to the space charge effect. As a method for solving this, Patent Document 3 discloses a method in which a high acceleration electron beam is decelerated immediately before a sample and is irradiated as a substantially low acceleration electron beam on the sample.

  Moreover, as a method for acquiring an electron beam image at high speed, Patent Document 3 discloses a method for continuously irradiating and acquiring an electron beam on a semiconductor wafer on a sample table while continuously moving the sample table.

  As an operation screen display method to be improved in consideration of the screen function of the wafer appearance inspection apparatus, an inspection using the operation screen, an inspection condition setting method, and the like are described, and a technique for efficiently inspecting in a short time is disclosed in Patent Document 4. Yes.

  Prior to pattern inspection, Patent Literature 5 stores irradiation history by charged particle beams as already-irradiated information for each audit target region, and distinguishes between irradiated and non-irradiated portions based on the information, and shows the effect of charge-up. A pattern inspection apparatus which is not received is shown.

"Monthly Semiconductor World" August 1995, p96-99

JP-A-5-258703 JP 59-1555941 A JP-A-5-258703 JP 2000-193594 A Japanese Patent Laid-Open No. 2002-150988

  None of the conventional inspection apparatuses described above considers the screen function of the wafer inspection apparatus. Therefore, when processing chip inspection, wafer sampling inspection, etc. while looking at the screen, not only the screen itself is unclear but also quick processing, and also quickly detect defects that cover the entire product or in specific areas. I could not.

It is an object of the present invention to quickly process a circuit pattern image to be inspected through a monitor screen with accurate information on the screen, and quickly detect defects in the entire product or in a specific area. it is to provide an inspection how the circuit pattern can be.

The present invention irradiates a substrate surface on which a circuit pattern of a wafer is formed with an electromagnetic wave or a charged particle beam, and detects a defect of the circuit pattern from an inspection image obtained based on a signal generated from the substrate by the irradiation. A method for inspecting a pattern, wherein at least one of before and after irradiation of the electromagnetic wave or charged particle beam when acquiring the inspection image, the corresponding portion of the inspection image is irradiated with an electron beam or a charged state of the wafer (1) Before the electromagnetic wave or charged particle beam irradiation for acquiring the inspection image for each row die of the wafer , the inspection image is set. The electromagnetic wave that acquires the inspection image at or near the corresponding part of the irradiation after irradiating the corresponding part or the vicinity thereof with the electron beam Performs a irradiation of the charged particle beam, then the corresponding portion or sequentially it is preferred to perform the operations of irradiating the electron beam in the vicinity of the test image the irradiation of the inspection image acquisition will be described later (2) - ( 7) The method according to any one of the above items is included .

  Before acquiring the inspection image, at least one of the brightness and contrast of the inspection image is changed by irradiating the corresponding portion of the inspection image or its vicinity with an electron beam to change the charged state of the wafer. The brightness and contrast of the inspection image can be obtained by charging due to the emission of secondary electrons due to the irradiation of the electron beam with a relatively low acceleration voltage in advance.

  After obtaining the inspection image, the corresponding portion of the inspection image or its vicinity is irradiated with an electron beam to remove the charged charge on the entire wafer or accelerate the charging. The removal of charged charges or the acceleration of charging can be obtained by supplying electrons by suppressing the emission of secondary electrons by irradiation of an electron beam with a relatively high acceleration voltage.

In the present invention , the irradiation means for irradiating the substrate surface on which the circuit pattern of the wafer is formed with charged particle beams such as visible light, ultraviolet light, infrared light, laser light, electron beam, ion beam, and the like; Detection means for detecting a signal generated from the substrate by irradiation, storage means for imaging and storing the signal detected by the detection means, and comparing the stored image with a reference image formed from the same circuit pattern comparison means for, an inspection apparatus for circuit pattern having a discriminating means for discriminating a defect on the circuit pattern from the comparison result, when an inspection of the c Eha, before obtaining the test image, Those having the function of changing the charged state of the wafer by irradiating the same part with an electron beam and setting the brightness and contrast of the inspection image are preferable .

Electron beam irradiation performed at least before and after the acquisition of the inspection image can arbitrarily change the time interval between the irradiation of the electromagnetic wave or the electron beam as the charged particle beam in the image acquisition for the inspection, Can be irradiated with other electron beams in advance between the time of irradiation and the acquisition of images for inspection, and the acceleration voltage, electron dose, and internal electromagnetic fields as parameters of electron beam generation can be changed arbitrarily It can be different from the parameters at the time of inspection, the electron beam irradiation width and the irradiation speed can be changed, and can be set independently so as to be different from the parameters at the time of inspection.

  Also, the irradiation direction of the electron beam can be arbitrarily set, and the parameters can be changed on the screen, for example, from top to bottom or from bottom to top, and the scanning direction at the time of inspection and the scanning direction before and after the inspection are scanned in the opposite direction. It is preferable. The scanning direction before and after the inspection is preferably the same direction. Although it is preferable to make the vibration width of the electron beam in the scan before and after the inspection larger than the vibration width of the electron beam in the scan at the time of inspection, the reverse may be possible.

Preferably, the irradiation of the irradiation and before and after the electron beam of the electromagnetic wave or charged particle sagittal image acquisition for inspection performed as follows in the present invention. In the following method, the brightness of the test image by performing with a time lag irradiation in electromagnetic wave or charged particle sagittal image acquisition for inspection to radiation before and after the electron beam, contrast adjustment In addition, it is possible to easily remove charge and adjust acceleration. Further, it is possible to eliminate the waiting time at each of the irradiation by the following appropriate combination of irradiation procedure of the electromagnetic wave or charged particle sagittal image acquisition for inspection and the irradiation procedure before and after the electron beam.

And irradiation of the electron beam is carried out in at least one of before and after obtaining the test image, sequentially performing the irradiation of the electromagnetic wave or charged particle sagittal acquiring the test image for each one row die of the wafer.

(2) after irradiation of advance the electron beam to obtain the test image, the electromagnetic wave or the irradiation of the charged particle sagittal across a row die of the wafer unirradiated of the electron beam to obtain the inspection image Next, the operation of performing the irradiation of the electron beam before acquiring the inspection image on the one-line die of the next wafer after the irradiation of the electron beam prior to acquiring the inspection image is sequentially repeated .

(3) after the irradiation of advance the electron beam to obtain the test image was carried out three rows successively for each one row die of the wafer, before the irradiation of the electromagnetic wave or charged particle sagittal obtaining the inspection image article performed in a row die of the wafer in the first part was irradiated in front of the electron beam, followed by the irradiation of the electromagnetic wave or charged particle sagittal acquires irradiated with the inspection image of the pre of said electron beam Are sequentially performed for each row die of the wafer.

(4) After irradiation of the electromagnetic wave or charged particle sagittal obtaining said inspection image of a row die of the wafer, just before performing the irradiation of the electromagnetic wave or charged particle sagittal obtaining the inspection image a row die performs irradiation of the electron beam after obtaining the inspection image in a row die of the wafer, and then the next of said wafer subjected to irradiation of the electromagnetic wave or charged particle sagittal obtaining said inspection image sequentially repeating the operation of performing the irradiation of the electromagnetic wave or charged particle sagittal obtaining the inspection image.

(5) irradiation of the inspection after the radiation of the electromagnetic wave or charged particle sagittal acquires image sequentially performed for two rows dies of the wafer, the electromagnetic wave or charged particle sagittal acquires before said inspection image was subjected to irradiation of the electron beam after obtaining the inspection image in a row die of the wafer was performed, the obtaining the inspection image after then the electromagnetic waves or following the performing the irradiation of the charged particle sagittal the wafer of the electromagnetic wave or the electromagnetic wave or partially subjected to irradiation of the charged particle sagittal obtaining said inspection image immediately before irradiation and the irradiation of the charged particle sagittal acquiring the test image in a row die of a wafer returns Ri Repetitive an operation in a row die performing irradiation of the pre-said electron beam.

(6) the after irradiation of advance the electron beam to obtain the inspection image of a row die of the wafer, the electromagnetic wave or the pre of the electron irradiation of the charged particle sagittal obtaining said inspection image performs irradiation of the electromagnetic wave or charged particle sagittal acquiring the test image in a row die of the wafer just before irradiation of the line, then the irradiation of the electromagnetic wave or charged particle sagittal obtaining said inspection image The first row die after the wafer that has been irradiated with the electron beam after the irradiation with the electron beam after the inspection image is acquired on the first row die immediately before the one row die of the wafer that has been performed. returns Ri Repetitive operation of performing irradiation of the pre of the electron beam.

(7) were successively subjected to irradiation of advance the electron beam to obtain the inspection image of the two column die of the wafer, prior articles before the irradiation of the electromagnetic wave or charged particle sagittal obtaining said inspection image Performed on the first row die of the wafer that has been irradiated with the previous electron beam, and then performed on the first row die of the wafer that has been subsequently irradiated with the previous electron beam. returns Ri Repetitive an operation of performing irradiation of the electron beam.

Parameters related to the acceleration voltage, electron dose, and internal electromagnetic field for generating the electron beam at least before and after obtaining the inspection image are electromagnetic waves or charged particle beams for obtaining the inspection image , and the electron beam It is different from the parameters related to the acceleration voltage, electron dose and internal electromagnetic field .

The electromagnetic wave or charged particle beam for obtaining the inspection image is the electron beam irradiation width and irradiation speed parameter at least one before and after obtaining the inspection image , and the electron beam irradiation width and irradiation speed. It is different from the parameter.

The irradiation direction of the electron beam performed at least one before and after acquiring the inspection image is different from the irradiation direction of the electron beam, and the electromagnetic wave or the charged particle beam acquiring the inspection image is an electron beam.

  According to the present invention, chip inspection, wafer sampling inspection, and the like can be quickly processed while viewing the screen, so that defects that cover the entire product or defects in a specific region can be detected quickly. In addition, it is possible to reliably detect changes in process conditions and feed back to the process, and at the same time, feed back to adjustment of the man-hours and payout budget.

  By applying the inspection apparatus of the present invention to the substrate product process, abnormalities such as product devices and conditions can be detected early and with high accuracy by referring to the screen, so that the abnormality countermeasure processing is promptly performed in the substrate manufacturing process. Can be taken. As a result, the defect rate of semiconductor devices and other substrates can be reduced and productivity can be increased.

  Hereinafter, embodiments of the circuit pattern inspection apparatus will be described in detail with reference to the drawings. This embodiment is intended for inspection of defects such as a resist pattern, a CONT opening pattern, a fine pattern after etching (diffusion system), and a fine pattern after etching (wiring system).

  FIG. 1 is a configuration diagram of a circuit pattern inspection apparatus according to the present invention. The circuit pattern inspection apparatus 1 includes an inspection chamber 2 in which the chamber is evacuated, and a preliminary chamber (not shown in the present embodiment) for transporting the substrate 9 to be inspected into the inspection chamber 2. The chamber is configured so that it can be evacuated independently of the examination chamber 2. The circuit pattern inspection apparatus 1 includes a control unit 5 and an image operation unit 6 in addition to the inspection room 2 and the spare room.

Laboratory 2 roughly comprises an electron optical system 3, a secondary electron detector 20, a sample chamber 8, and an optical microscope unit 4. The electron optical system 3 includes an electron gun 10, an electron beam extraction electrode 11, a condenser lens 12, a blanking deflector 13, a scanning deflector 15, a diaphragm 14, an objective lens 16, a reflecting plate 17, and an ExB deflector 18. An irradiation means is formed. Among the secondary electron detector 20, a secondary electron detector 20 is arranged above the objective lens 16 in the inspection chamber 2. The output signal of the secondary electron detector 20 is amplified by a preamplifier 21 installed outside the examination room 2 and converted into digital data by an AD converter 22. The sample chamber 8 includes a sample stage 30, an X stage 31, a Y stage 32, a rotary stage 33, a position monitor length measuring device 34, and a substrate height measuring device 35 to be inspected.

  The optical microscope section 4 is composed of a light source 40, an optical lens 41, and a CCD camera 42, and is provided in the vicinity of the electron optical system 3 in the examination room 2 and at a position that is far enough not to affect each other. The distance between the electron optical system 3 and the optical microscope unit 4 is known.

The X stage 31 or the Y stage 32 can reciprocate a known distance between the electron optical system 3 and the optical microscope unit 4. Further, the rotary stage 33 or the sample stage may be configured such that the angle at which the primary electron beam 19 is irradiated onto the sample 9 can be varied by tilting an arbitrary side thereof. In the present embodiment, and it performs irradiation of the irradiation and before and after the electron beam of the electron beam to obtain an inspection image by using a primary electron beam 19.

  The control unit 5 includes an overall control unit 49, storage means 45 for converting the analog signal from the secondary electron detection unit 20 into a digital signal and storing it, an image processing circuit 46 for processing the stored digital signal, and an image processing circuit 46. An inspection condition setting unit 48 for setting the processing parameters, and a defect data buffer 47 for holding defect information which is a processing result of the image processing circuit 46.

  The image operation unit 6 includes a first image storage unit 51, a second image storage unit 52, a comparison calculation unit 53, and a defect determination processing unit 54. An image display unit 56 arbitrarily selects an electron beam image, a defect image, or the like. To display. Further, a map display unit 55 for displaying the position of the sample and instructing movement, an image acquisition instruction unit 57, an image processing instruction unit 58, and a processing condition setting unit 59 are provided. Furthermore, it has a mode switching unit 62 for dividing the mode according to the operation content.

  Operation commands and operation conditions of each part of the apparatus are input / output from the image operation unit 6. The image operation unit 6 is input in advance so that conditions such as an acceleration voltage at the time of generating an electron beam, an electron beam deflection width, a deflection speed, a signal capturing timing of a secondary electron detector, a sample stage moving speed, and the like can be set according to the purpose. Has been.

  The control unit 5 uses the correction control circuit 61 to monitor the position and height deviation from the signals of the position monitor length measuring device 34 and the inspection board height measuring device 35, and generates a correction signal based on the result, thereby generating an electron beam. A correction signal is sent to the objective lens power supply 44 and the scanning signal generator 43 so that the correct position is always irradiated.

  In order to acquire an image of the substrate 9 to be inspected, the primary electron beam 19 that is narrowed down is irradiated onto the substrate 9 to be inspected to generate secondary electrons 51, which are scanned by the primary electron beam 19 and the stages 31 and 32. An image of the surface of the inspected substrate 9 is obtained by detecting in synchronization with the movement of.

  As described above, a high inspection speed is essential for the automatic inspection of the present invention. Therefore, unlike an ordinary SEM, an electron beam having an electron beam current of the pA order is scanned at a low speed, and scanning is not performed many times or each image is superimposed. Further, in order to suppress charging of the insulating material, it is necessary to scan the electron beam once or several times at a high speed.

In this embodiment, an image is formed by scanning a high-current electron beam of about 100 times or more, for example, 100 nA, for example, only once compared with a normal SEM. The scan width was 100 μm, one pixel was 0.1 μm ^2, and one scan was performed in 1 μs.

  The electron gun 10 uses a diffusion replenishment type thermal field emission electron source. By using this electron gun 10, it is possible to secure a stable electron beam current as compared with a conventional tungsten (W) filament electron source or a cold field emission type electron source. An image is obtained. In addition, since the electron beam current can be set large by the electron gun 10, high-speed inspection can be realized.

  The primary electron beam 19 is extracted from the electron gun 10 by applying a voltage between the electron gun 10 and the extraction electrode 11. The primary electron beam 19 is accelerated by applying a high-voltage negative potential to the electron gun 10. The primary electron beam 19 travels in the direction of the sample stage 30 with energy corresponding to the potential, is converged by the condenser lens 12, and further narrowed down by the objective lens 16, on the XY stages 31 and 32 on the sample stage 30. Irradiated to the substrate 9 to be inspected. The inspected substrate 9 is a semiconductor wafer, a chip or a substrate having a fine circuit pattern such as a liquid crystal and a mask. The blanking deflector 13 is connected to a scanning signal generator 43 that generates a scanning signal and a blanking signal, and the condenser lens 12 and the objective lens 16 are connected to a lens power source 44, respectively.

  A negative voltage is applied to the substrate 9 to be inspected by the retarding power source 36. By adjusting the voltage of the retarding power source 36, the primary electron beam can be decelerated and the electron beam irradiation energy to the substrate 9 to be inspected can be adjusted to an optimum value without changing the potential of the electron gun 10. Secondary electrons 51 generated by irradiating the substrate 9 to be inspected with the primary electron beam 19 are accelerated by a negative voltage applied to the substrate 9 to be inspected.

  The ExB deflector 18 is disposed above the substrate 9 to be inspected, and the secondary electrons 51 accelerated thereby are deflected in a predetermined direction. The amount of deflection can be adjusted by the voltage applied to the ExB deflector 18 and the strength of the magnetic field. The electromagnetic field can be varied in conjunction with a negative voltage applied to the sample. The secondary electrons 51 deflected by the ExB deflector 18 collide with the reflection plate 17 under a predetermined condition. The reflection plate 17 has a conical shape integrally with a shield pipe of a deflector of an electron beam (hereinafter referred to as a primary electron beam) irradiated on a sample. When the accelerated secondary electrons 51 collide with the reflector 17, second secondary electrons 52 having an energy of several eV to 50 eV are generated from the reflector 17.

  The secondary electron detector 7 is connected to a secondary electron detector 20 provided in the inspection chamber 2 evacuated. Outside the examination room 2, a preamplifier 21, an AD converter 22, an optical conversion unit 23, an optical transmission unit 24, an electrical conversion unit 25, a high voltage power source 26, a preamplifier driving power source 27, an AD converter driving power source 28, and a reverse bias power source 29. There is. As described above, in the secondary electron detector 7, the secondary electron detector 20 is disposed above the objective lens 16 in the examination room 2. The secondary electron detector 20, the preamplifier 21, the AD converter 22, the optical conversion means 23, the preamplifier drive power supply 27, and the AD converter drive power supply 28 are floated to a positive potential by the high voltage power supply 26. The second secondary electrons 52 generated by colliding with the reflecting plate 17 are guided to the secondary electron detector 20 by this attractive electric field.

  The secondary electron detector 20 is a second secondary generated by the secondary electrons 51 generated while the primary electron beam 19 is irradiated onto the substrate 9 to be inspected and then colliding with the reflector 17. The electron 52 is configured to be detected in conjunction with the scanning timing of the primary electron beam 19. The primary electron beam 19 is irradiated with vibration with a predetermined amplitude with respect to the traveling direction of the substrate 9 to be inspected.

  The output signal of the secondary electron detector 20 is amplified by a preamplifier 21 installed outside the examination room 2 and converted into digital data by an AD converter 22. The AD converter 22 is configured to immediately convert the analog signal detected by the secondary electron detector 20 into a digital signal after being amplified by the preamplifier 21 and transmit the digital signal to the control unit 5. Since the detected analog signal is digitized immediately after detection and then transmitted, a high-speed signal with a high S / N ratio can be obtained.

  The substrate 9 to be inspected is mounted on the XY stages 31 and 32, and when the inspection is executed, the XY stages 31 and 32 are stopped and the primary electron beam 19 is scanned two-dimensionally. Alternatively, it is possible to select one of scanning the primary electron beam 19 linearly in the X direction so that the XY stages 31 and 32 are continuously moved in the Y direction at a constant speed when the inspection is performed. When inspecting a specific relatively small area, the former stage is inspected with the stationary stage, and when inspecting a relatively large area, the stage is continuously moved at a constant speed and inspected. It is. When the primary electron beam 19 needs to be blanked, the blanking deflector 13 deflects the primary electron beam 19 so that the electron beam does not pass through the diaphragm 14.

  As the position monitor length measuring device 34, a length measuring device based on laser interference is used in this embodiment. The positions of the X stage 31 and the Y stage 32 can be monitored in real time and transferred to the control unit 5. In addition, data such as the rotational speeds of the motors of the X stage 31, the Y stage 32, and the rotary stage 33 are similarly transferred from each driver to the control unit 5. Based on these data, the control unit 5 can accurately grasp the region and position where the primary electron beam 19 is irradiated. Further, the correction control circuit 61 corrects the displacement of the irradiation position of the primary electron beam 19 in real time as necessary. In addition, the region irradiated with the electron beam can be stored for each substrate to be inspected.

  As the inspected substrate height measuring device 35, an optical measuring device that is a measuring method other than the electron beam, for example, a laser interference measuring device or a reflected light measuring device that measures changes at the position of reflected light is used. The height of the inspected substrate 9 mounted on the XY stage 31, 32 is measured in real time. In the present embodiment, elongated white light that has passed through the slit is irradiated onto the inspected substrate 9 through a transparent window, the position of the reflected light is detected by a position detection monitor, and the amount of change in height is calculated from the change in position. The method to be used was used.

  Based on the measurement data of the inspected substrate height measuring device 35, the focal length of the objective lens 16 for narrowing the primary electron beam 19 is dynamically corrected, and the primary electron beam 19 always focused on the non-inspection region. Can be irradiated. It is also possible to measure the warpage and height distortion of the inspected substrate 9 before electron beam irradiation, and to set correction conditions for each inspection region of the objective lens 16 based on the data. It is.

  Next, the configuration of the image operation unit 6 will be described. The image signal of the inspected substrate 9 detected by the secondary electron detector 20 is amplified by the preamplifier 21, digitized by the AD converter 22, converted to an optical signal by the light conversion means 23, and the light transmission means 24. Transmitted by. After being converted again into an electric signal by the electric conversion means 25, it is stored in the first image storage unit 51 or the second image storage unit 52 of the image operation unit 6 through the overall control unit 49 of the control unit 5.

  The comparison calculation unit 53 aligns the stored image signal with the image signal of the other storage unit, performs standardization of the signal level, and performs various image processing for removing the noise signal, and converts both image signals. Perform a comparison operation. The defect determination unit 54 compares the absolute value of the difference image signal calculated by the comparison operation unit 53 with a predetermined threshold value, and if the difference image signal level is greater than the predetermined threshold value, It is determined as a defect candidate, and the position, the number of defects, and the like are displayed on the image display unit 56.

  Next, how to set conditions during inspection will be described. FIG. 2 shows a screen configuration of the image operation unit 6 and an initial screen for inspection. In this screen, a map display unit 55 indicating the current stage position and an image display unit 56 on which an optical microscope image of the optical microscope unit 4 is displayed are shown. By clicking on this map display section 55, the stage 31, 32 is moved to select a place where conditions are set. Further, by clicking on the image acquisition support unit 57 of the image operation unit 6, the electron beam 19 is irradiated onto the substrate 9 to be inspected, and the generated secondary electrons are detected by the secondary electron detector 20 and converted into digital signals. Then, a digital image of a predetermined area is acquired in the storage means 45.

  The processing conditions are set by the processing condition setting unit 59 of the image operation unit 6 and the image processing instruction unit 58 is clicked. Further, the inspection condition setting unit 48 of the control unit 5 is set, and the digital image stored in the storage unit 45 is processed by the image processing circuit 46 based on the setting condition, and the defect is extracted and stored in the defect buffer 47. In this way, the image acquired area is enlarged and displayed on the map display unit 55, the position of the defect is visually recognized, and the image on the storage unit 45 of the defect position is displayed on the image display unit 56 by clicking this position. .

  By repeating these operations, search conditions suitable for inspection are searched. When the condition confirmation at one place is completed, the map display section 55 is reduced again, the image display section 56 is switched to the optical microscope image, the condition setting location is reselected, and the process from image acquisition to condition setting is repeated.

  Next, various parameters necessary for executing the inspection in the present embodiment will be described. The parameters include parameters specific to the substrate 9 to be inspected and parameters that determine the operating conditions of the apparatus.

  Parameters inherent to the substrate 9 to be inspected are roughly divided into two types. One is a parameter called “product file”, which does not change depending on the layer in the manufacturing process. For example, the wafer size, the orientation flat or notch shape, the exposure shot size of the semiconductor product, the chip (die) size, the memory cell area, the size of the memory cell repeat unit, and the like. These are tabulated as “product file”.

  The other is a parameter called “process file”, which requires adjustment because the surface material and the shape of the surface differ depending on the layer in the manufacturing process. For example, these are registered as a “process file” in terms of electron beam irradiation conditions, various gains of the detection system, image processing conditions for detecting defects, and the like.

  At the time of inspection, the inspection condition corresponding to a specific semiconductor product and a specific manufacturing process can be called by designating the “product file” and the “process file”. In this embodiment, the “product file” and the “process file” are collectively referred to as “recipe”. A series of operations for inputting and registering these various parameters is referred to as “recipe creation”.

  The recipe creation method and the operation screen for executing the recipe will be described below. The screen of FIG. 2 is roughly divided into five areas. The area (1) is arranged in the upper part of the screen, and displays the device name, device ID, recipe file name, process file name, and the like as recipe names. In the area (2), guidance for explaining operations and states is displayed.

  The display content of the area (3) in the center of the screen changes depending on the operation and progress. The area (4) on the right side of the screen displays operation buttons that are commonly required for a plurality of screens, and includes “print”, “save file”, “start”, “end”, “save image”, and the like. For example, when “Save File” is pressed, a screen for designating the name of the product file and process file for saving the recipe currently being created is displayed. When “Save Image” is pressed, a screen for designating a name for saving the currently displayed image as an image file is displayed.

  In the operation area (5) at the bottom of the screen, the mode name is displayed. For example, when “inspection” is pressed, the automatic inspection is executed, and when “recipe creation” is pressed, the above parameters are input.

  FIG. 3 shows a processing flow of the recipe creation mode. When the “recipe creation” mode is selected on the initial screen of FIG. 2, the mode switching means 60 functions and switches to the recipe creation screen shown in FIG. Since the start button is pressed on this screen and the cassette shelf number is displayed, the shelf number is first designated (S1). Next, the recipe file is called, and the product condition, whether new or changed, is input, and the lot ID and wafer ID are input (S2).

  This change is a change in recipe creation conditions, regardless of whether or not it is loaded, and is mainly a load change. In addition, since recipes of other devices to be described later cannot be directly input, an inspection result file (defect information file: the contents of this file is disclosed to the user) is input, converted, and a recipe for the own device And change in this step to make up for the missing data.

  Here, the wafer cassette is newly created, and then the wafer cassette is installed in the loader of the inspection apparatus (S3). As the items, (1) OF or notch is detected, (2) is held in the sample holder (sample exchange chamber), and (3) the sample holder is transferred to the examination room stage.

  Next, the stage is moved to the stage reference mark, and absolute calibration of the beam is performed (S4). Calibration is performed based on default recipe file conditions, and (1) beam irradiation, (2) deflection correction, reference coordinate correction, and (3) focus parameter correction are performed.

  Next, the designated position on the sample is irradiated with an electron beam, and the focus and astigmatism are readjusted after confirming the image contrast on the sample (S5). At this time, if sufficient contrast cannot be obtained, the electron beam irradiation conditions are changed. Here, the designated irradiation conditions, focal points, and astigmatic conditions are stored in the process file as recipe parameters.

  When the electron beam irradiation conditions are determined and the contrast is confirmed, the shot of the wafer and the size and arrangement of the die (chip) are input (S6). When the shot size and the shot matrix are input, and the arrangement of the dies in the shot is input, the shot on the wafer peripheral portion or the presence / absence of the die is designated. The shot and die arrangement set here are stored as parameters in the recipe file.

  Next, alignment condition input and alignment are executed (S7). (1) Alignment chip designation (multiple points), (2) Move to the origin of the first chip, (3) Switch the optical microscope monitor, (4) Manually move to the alignment mark position of the first chip. (5) Register the optical image, (6) Switch to the SEM image mode, (7) Fine-adjust manually to the alignment mark position, (8) SEM image registration, (9) Alignment coordinate registration.

  As items for alignment execution, (1) first point movement, (2) image input / search / matching, (3) second point movement, (4) image input / search / matching, (5) remaining point (6) Inclination / position / chip interval correction.

  Also, as offset setting of the chip origin, (1) move to the last point alignment mark, (2) specify the alignment mark position (SEM image mode), (3) move to the first chip origin, (4) specify the chip origin position (SEM image mode), (5) Chip origin-alignment mark offset calculation and registration. The offset of the chip origin is the distance between the alignment coordinates and the origin coordinates of the chip where the mark is located.

  In this way, the offset value between the designated alignment pattern coordinates and the chip origin is input and registered as an alignment parameter in the process file. In recipe creation, since there are many parameters for specifying coordinates for executing various processes on the wafer, alignment conditions are first determined and registered, and execution is performed up to alignment.

  Next, the memory cell area in the chip is set (S8). The items include (1) cell area input, (2) cell pitch input, and (3) (1), (2) registration. The cell area is input using an optical microscope image and an electron beam image.

  Next, die area setting is performed (S9). The items include (1) die area input, (2) die non-inspection area input, and (3) (1) and (2) registration. The die area is also input using an optical microscope image and an electron beam image.

  Next, an inspection area is designated (S10). In specifying the inspection area, two types of inspection area and inspection area in the die can be specified. When it is not necessary to inspect all the dies, or when it is desired to inspect only a specific area in the die, it can be arbitrarily designated as described later. Furthermore, the inspection sampling rate can be specified for the specified area. Also, the inspection direction can be specified. Die area and inspection area data are stored as parameters in the process file.

  When the specification of the inspection area is completed, the process proceeds to calibration setting for adjusting the brightness at the time of inspection (S11). In calibration, an image is acquired, and hardware gain adjustment and brightness correction are performed according to the signal amount from the brightness distribution. Actually, it is carried out by specifying a die to be calibrated and coordinates within the die. The coordinate value for performing calibration, the gain of brightness, and the offset value are stored as parameters in the process file.

  Next, an image is actually acquired under various conditions set so far, and image processing conditions for detecting defects are set (S12). First, when acquiring an image, the type of filter to be applied to the detection signal is selected. Then, an image of a small area in one chip is actually acquired under the same conditions as the inspection. Here, the small area refers to an area having a width of 100 μm, which is an operation width of an electron beam, and a length corresponding to one chip. When the image is acquired, a threshold value for determining a defect is input, and an image of a portion determined to be a defect is displayed. By repeating this, the optimum inspection condition is determined. This series of operations is called “small area test inspection”. The parameters such as the threshold value and file set here are stored as parameters of the in-process file.

  Various parameters necessary for the inspection can be set by the above various inputs. However, in actual semiconductor wafers, there are process variations within the wafer surface and between production lots, so it is not sufficient to set image processing conditions in the small area test inspection. It is necessary to determine a threshold value.

  Therefore, the final inspection is performed with the created recipe file (S13). (1) Stage constant speed continuous movement, position / height monitoring, (2) beam scanning, real time correction (stage / Z sensor tracking), (3) secondary electron detection, AD conversion, image memory (4) Image processing and comparison determination, (5) Beam correction for each N stripe, and (6) Display of defect number and defect position.

  Based on the monitor result, the defect detection level and the false detection level are confirmed (S14). If the conditions are finally appropriate, various parameters input so far are registered in the product file and the process file (S15). . Finally, the wafer is unloaded (S16).

  Next, in the inspection apparatus in the above “recipe creation”, an image is acquired by one-time electron beam irradiation. Due to the characteristics of the wafer, a single electron beam irradiation may cause uneven image contrast or insufficient contrast of the target region. In such a case, the irradiation amount of the electron beam is usually increased by irradiating the same line of the image a plurality of times. However, when the irradiation amount is increased by such a method, the potential temporarily changes locally and there is a risk of causing destruction of the wafer. In addition, since the same line is irradiated a plurality of times, the inspection time is delayed.

  In the present invention, instead of irradiating the same line a plurality of times, one die or one row die is irradiated a plurality of times in advance, and an image at the time of the last one row die irradiation is used as an inspection image. By repeating irradiation for one row die, a time delay occurs, and the local potential enhancement can be reduced. In addition, by specifying the time interval between the irradiation for one row die to be irradiated in advance and the irradiation for one row die for obtaining the inspection image, the transient state of charging due to the pattern density and structure of the wafer is used as the inspection image. It is possible to capture, and it is possible to capture as an inspection image an image with good contrast or with a defect portion emphasized.

  In addition, by performing pre-irradiation for different one-row dies by using the time between irradiation for one-row die to be irradiated in advance and irradiation for one-row die for obtaining the inspection image, The waiting time with irradiation for inspection can be used effectively. When there is further waiting time, it is possible to carry out pre-irradiation for different multi-row dies. In addition, when the irradiation for one row die is repeated, the charged state on the wafer can be changed by changing the electron optical conditions (for example, acceleration voltage, irradiation current amount, etc.), and more flexible inspection becomes possible. . The image used for the inspection uses the image at the time of the last electron beam irradiation. Since the charged state of the wafer can be changed, the contrast of the image highlighting the defect can be obtained, so that the inspection efficiency is improved.

  Further, when the irradiation for one row die is repeated, the width of one line and the width between the lines can be varied, so that the charged state of the wafer can be further varied flexibly. Further, by making the direction of irradiation in advance (the direction of the die to be inspected) the same as the direction used for the inspection, it is possible to provide uniform charging over time. Conversely, the inspection time can be shortened by reversing the direction used for the inspection.

  Next, in the present invention, after acquiring inspection images for one die or one row of die, the same portion is irradiated a plurality of times afterward to move to the inspection of the next die. In conventional inspection, when an inspection image for one die for inspection or one row die is acquired, the charging of the wafer changes thereby, and by irradiating the next row of dies or the next inspection portion, A phenomenon in which electrification accumulates occurred. As the wafer is charged, the electron beam is bent by the electric field, and the contrast of the acquired image changes as the number of times of irradiation is increased, and is often detected as a pseudo defect.

  In this example, the charged state generated by the inspection can be returned to the original state by irradiating the electron beam once or a plurality of times after irradiating the portion for one die or one row die irradiated for inspection, or conversely The purpose is to accelerate the charged state at an early stage and bring it into a saturated state.

  By specifying the time interval between the irradiation for one row die to obtain the inspection image and the irradiation for one row die to be irradiated afterwards, the transient state of charging due to the pattern density and structure of the wafer can be made early and stable. In other words, it is possible to change the state before the original irradiation, and it is possible to manage the charged state of the adjacent portion to be inspected next. This contributes to capturing an image in which the site to be inspected next has good contrast or the defect portion is emphasized as an inspection image.

  In addition, by using the time between the irradiation for one row die to acquire the inspection image and the irradiation for one row die to be irradiated after the fact, the post irradiation is performed by performing the inspection irradiation for different one row die. The waiting time with irradiation for inspection can be used effectively. When there is further waiting time, it is possible to carry out inspection irradiation for different multi-row dies.

  The electron optical conditions of the electron beam irradiated after obtaining the inspection image can be changed at the time of irradiation for one row die, as in the case of irradiation performed in advance. Similarly, by changing the width of one line, the width between lines, or changing the irradiation direction, the charged state of the wafer can be flexibly changed.

(Sequence showing the scanning operation of the circuit pattern inspection apparatus according to the present invention)
FIG. 5 is a sequence diagram showing a pre-post scan operation in the case of sequentially performing one pre-irradiation (pre-scan), inspection irradiation (inspection scan), and one post-irradiation (post-scan) without waiting time. In the case of the first one-line die as an example, a series of steps of performing pre-irradiation indicated by a dotted line, then performing inspection irradiation for obtaining an inspection image indicated by a solid line, and then performing post-irradiation (post-scan) indicated by a broken line As a pair, move to the next one-line die and perform a series of steps in the same manner. This example is an experimental example in the case where there is no waiting time between inspection irradiation and pre-irradiation, and inspection irradiation and post-irradiation. The present embodiment proposes an example in which there is a waiting time between inspection irradiation and preliminary irradiation, and inspection irradiation and post-irradiation.

  In FIG. 5, the irradiation of the electron beam performed at least one before and after acquiring the inspection image and the irradiation of the electron beam acquiring the inspection image are sequentially performed for each row die of the wafer.

  FIG. 6 is a sequence diagram when there is a waiting time for pre-irradiation (pre-scan) and inspection irradiation (inspection scan). After performing the first pre-irradiated single row die (1), the irradiation (2) for acquiring the inspection image is performed on the die two rows before the pre-irradiated single row die. The next pre-irradiation is performed on the next one-line die of (1) (3), and the irradiation for obtaining the inspection image is performed on the next first-line die of (2) (4). After the pre-irradiation in (5) is completed, irradiation for obtaining the inspection image in (6) is performed. Since the pre-irradiation at the position (6) is executed before the irradiation for the two inspections (2) and (4), as a result, the inspection of (6) waits for the inspection time for two rows of dies. It will be done. Further, in this example, the irradiation direction for inspection and the irradiation direction for preliminary irradiation are reversed, and the time required for the entire inspection can be shortened because the movement time is short. Conversely, in an example in which the irradiation direction for inspection and the irradiation direction of pre-irradiation are the same, the waiting time between each single row die and the single row die can be made more accurate.

  FIG. 6 shows that after irradiation of the electron beam in advance to acquire the inspection image, irradiation of the electron beam for acquiring the inspection image is performed with the one-line die of the wafer not irradiated with the electron beam interposed therebetween, and then the inspection image is acquired. The operation of performing the previous electron beam irradiation on the one-line die of the next wafer after the previous electron beam irradiation for obtaining the inspection image is sequentially performed.

  FIG. 7 is a sequence diagram when there is a waiting time for pre-irradiation (pre-scan) and inspection irradiation (inspection scan). In FIG. 6, the inspection image acquisition irradiations (2) and (4) are acquired without pre-irradiation. In FIG. 7, in order to perform pre-irradiation for acquiring the inspection image, the pre-irradiation of (1) and (2) is first performed continuously. As a result, efficient inspection can be performed by performing pre-irradiation for the first waiting time.

  FIG. 7 shows the initial irradiation of the electron beam for acquiring the inspection image after the irradiation of the electron beam for acquiring the inspection image is sequentially performed for three rows per one die of the wafer. This is performed on the one-line die of the wafer, and then the electron beam irradiation and the electron beam irradiation for obtaining the inspection image are sequentially performed for each one-line die of the wafer.

  FIG. 8 is a sequence diagram when there is a waiting time for inspection irradiation (inspection scan) and post-irradiation (post-scan). After performing the first inspection irradiation single row die (1), the post-irradiation (2) is performed on the previous die of the inspection irradiation single row die. The next inspection irradiation is performed on the next first row die of (1) (3), and the post irradiation is performed on the next first row die of (2) (4). At this time, the post-irradiation with respect to the inspection irradiation of (1) is performed. The charged state changed by the inspection irradiation of (1) can be restored by the post-irradiation of (4), or the transient state can be changed to a more stable state. After the post-irradiation in (4) is completed, irradiation for obtaining the inspection image in (5) is performed. Thereafter, post-irradiation at the position (6) is performed, and post-irradiation with respect to the inspection irradiation of (3) is performed.

  In this example, the irradiation direction for inspection and the irradiation direction of post-irradiation are reversed. The time required for the entire inspection can be shortened because the movement time is short. Conversely, in the example in which the irradiation direction for inspection and the irradiation direction of the post-irradiation are the same, the waiting time between each row die and the row die can be made more accurate.

  FIG. 8 shows an example in which an inspection image is acquired on the one-line die of the wafer immediately after the irradiation of the electron beam for acquiring the inspection image after the irradiation of the electron beam for acquiring the inspection image of the single-line wafer of the wafer. The operation of irradiating with an electron beam and then irradiating with an electron beam for acquiring an inspection image of the next-row die of the next wafer that has been irradiated with an electron beam for acquiring an inspection image is sequentially repeated.

  FIG. 9 is a sequence diagram in the case where there is a waiting time for post irradiation (post scan) and inspection irradiation (inspection scan). In FIG. 8, the post-irradiation (2) is performed without performing the inspection irradiation. In FIG. 9, in order to irradiate the post-irradiation for obtaining an inspection image, the inspection irradiation of (1) is first performed. As a result, efficient inspection can be performed by performing inspection irradiation for the first waiting time.

  FIG. 9 shows that after the electron beam irradiation for acquiring the inspection image is sequentially performed on the two-row dies of the wafer, the inspection image is acquired on the one-row die of the wafer subjected to the electron beam irradiation for acquiring the previous inspection image. Electron that obtains the inspection image immediately before irradiation and irradiation of the electron beam that obtains the inspection image on the next-row die of the next wafer that has been irradiated with the electron beam, and then obtains the subsequent inspection image. The operation of irradiating an electron beam in advance on the one-line die of the wafer in the portion where the irradiation has been performed is repeated.

  FIG. 10 is a sequence diagram in which one pre-irradiation (pre-scan) and inspection irradiation (inspection scan) in FIG. 6 is combined with one inspection irradiation (inspection scan) and post-irradiation (post-scan) in FIG. is there. First, after the preliminary irradiation of (1), the inspection irradiation of (2) is performed. Thereafter, post-irradiation (3) is performed. Next, a pair of pre-irradiation, inspection irradiation, and post-irradiation of (4), (5), and (6) is performed. According to the sequence at this time, the inspection irradiation of (5) becomes the inspection that received the pre-irradiation of (1), and the inspection of (2) received the post-irradiation of (6). By performing the following (7), (8), (9) pre-irradiation, inspection irradiation, and post-irradiation pairs, the inspection irradiation of (8) becomes the inspection that received the pre-irradiation of (4). In the inspection of (5), the pre-irradiation of (1) and the post-irradiation of (9) were respectively received after a certain period of time.

  In this example, the waiting time for pre-irradiation and inspection irradiation, and the waiting time for inspection irradiation and post-irradiation are the same example. come. In this example, the irradiation direction for inspection is opposite to the irradiation direction for pre- and post-irradiation, and the time required for the entire inspection can be shortened because the movement time is short. Conversely, in the example in which the irradiation directions for inspection and irradiation before and after the irradiation are the same, the waiting time between each row die and the row die can be made more accurate.

  FIG. 10 shows that after performing irradiation of an electron beam in advance to acquire an inspection image of a single row die of the wafer, irradiation of the electron beam to acquire an inspection image is performed on the single row die of the wafer immediately before performing irradiation of the prior electron beam. Irradiated with an electron beam to acquire an inspection image, and then irradiated with an electron beam after acquiring the inspection image on the first row die immediately before the first row die of the wafer that had been irradiated with the electron beam to acquire the inspection image. Thereafter, the operation of irradiating the electron beam on the next one-line die of the wafer that has been irradiated with the electron beam in advance is repeated.

  FIG. 11 is a sequence diagram that combines the pre-irradiation (pre-scan), inspection irradiation (inspection scan), and post-irradiation (post-scan) of FIG. In FIG. 10, the inspection is carried out in a state where the pre-irradiation is not performed before the post-irradiation and inspection irradiation in (2) and (6). Further, in (3), the pre-irradiation ends without any inspection irradiation. In FIG. 11, the pre-irradiation and inspection irradiation of (1), (2), and (3) are first performed in order to perform irradiation for obtaining the inspection image in the pre- and post-irradiation. As a result, efficient inspection is possible by performing pre-irradiation for the waiting time until the first inspection irradiation and inspection irradiation for the waiting time until the post-irradiation.

  FIG. 11 shows an example of a wafer that has been subjected to prior electron beam irradiation for acquiring an inspection image of a two-row die of a wafer, and then irradiated with an electron beam for acquiring an inspection image. The operation of performing the irradiation with the electron beam on the first row die and then irradiating the first row die with the next row of the wafer after the irradiation with the previous row of electron beams is repeated.

  FIG. 12 is an operation screen diagram showing parameter settings for this pre-irradiation (pre-scan) and post-irradiation (post-scan). As shown in FIG. 12, for the pre-irradiation and the post-irradiation, the waiting time interval with the inspection irradiation, the setting of the electro-optical conditions, the setting of the scanning direction, the acceleration voltage, the current amount, the number of repetitions, the scan width, the scan Line interval and delay time can be set. When the waiting time is set, the pre-irradiation die row and the inspection irradiation die row corresponding to the time are set to interrupt. Such setting of the cell region is applicable not only to the “SEM” image but also to the “optical microscope” image or the laser beam image.

As described above, according to this embodiment, or by changing the charged state of the wafer, to have a screen function that makes it possible to stable (constant), good time efficient, provides a test how the circuit pattern be able to.

  Further, according to the present embodiment, chip inspection, wafer sampling inspection, and the like can be quickly processed while looking at the screen, so that defects that cover the entire product or defects in a specific region can be detected quickly. In addition, it is possible to reliably detect changes in process conditions and feed back to the process, and at the same time, feed back to adjustment of the man-hours and payout budget.

  Furthermore, by applying the inspection method and apparatus of this embodiment to the substrate product process, it is possible to detect abnormalities such as product devices and conditions early and with high accuracy by referring to the screen. Abnormal countermeasures can be taken quickly in the process. As a result, the defect rate of semiconductor devices and other substrates can be reduced and productivity can be increased.

The block diagram of the circuit pattern inspection apparatus which concerns on this invention. The block diagram of the monitor part of the circuit pattern inspection apparatus which concerns on this invention. The flowchart which shows the recipe creation process of the circuit pattern inspection apparatus which concerns on this invention. Explanatory drawing which shows the recipe creation screen of the circuit pattern inspection apparatus which concerns on this invention. The sequence diagram which shows the test | inspection scan and pre-post scan operation which concern on an experiment example . The sequence diagram which shows the test | inspection scan and pre-scan operation | movement which concern on this invention. The sequence diagram which shows the test | inspection scan and pre-scan operation | movement which concern on this invention. The sequence diagram which shows the test | inspection scan and post-scan operation | movement concerning this invention. The sequence diagram which shows the test | inspection scan and post-scan operation | movement concerning this invention. The sequence diagram which shows the test | inspection scan and pre-post scan operation | movement which concern on this invention. The sequence diagram which shows the test | inspection scan and pre-post scan operation | movement which concern on this invention. Explanatory drawing which shows the parameter setting screen of the circuit pattern inspection apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Circuit pattern inspection apparatus, 2 ... Examination room, 3 ... Electron optical system, 4 ... Optical microscope part, 5 ... Control part, 6 ... Image operation part, 7 ... Secondary electron detection part, 8 ... Sample room, 9 ... Substrate to be inspected, 10 ... electron gun, 11 ... extraction electrode, 12 ... condenser lens, 13 ... blanking deflector, 14 ... aperture, 15 ... scanning deflector, 16 ... objective lens, 17 ... reflector, 18 ... ExB deflection 19 ... primary electron beam, 20 ... secondary electron detector, 21 ... preamplifier, 22 ... AD converter, 23 ... light conversion means, 24 ... light transmission means, 25 ... electrical conversion means, 26 ... high voltage power supply, 27 ... Preamplifier drive power supply, 28 ... AD converter drive power supply, 29 ... Reverse bias power supply, 30 ... Sample stage, 31 ... X stage, 32 ... Y stage, 33 ... Rotation stage, 34 ... Position monitor length measuring device, 35 ... Covered Inspection board height measuring instrument, 36 ... 40 ... white light source, 41 ... optical lens, 42 ... CCD camera, 43 ... scanning signal generator, 44 ... objective lens power supply, 45 ... storage means, 46 ... image processing circuit, 47 ... defect data buffer, 49 ... General control unit, 51 ... first image storage unit, 52 ... second image storage unit, 53 ... calculation unit, 54 ... defect determination unit, 55 ... map display unit, 56 ... image display unit, 60 ... mode switching unit, 61 ... correction control circuit.

Claims (9)

A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
Irradiation of the electron beam that changes the charged state of the wafer by irradiating an electron beam to or near the corresponding part of the inspection image at least before or after the electromagnetic wave or charged particle beam irradiation when acquiring the inspection image Set parameters related to conditions,
After irradiation of the electron beam in advance to acquire the inspection image, the electromagnetic wave or charged particle beam irradiation to acquire the inspection image is performed across a row die of the wafer of the unirradiated portion of the electron beam, and then Circuit pattern inspection characterized by sequentially repeating the operation of performing irradiation of the electron beam in advance to acquire an inspection image on the first row die of the wafer after irradiation of the electron beam in advance of acquiring the inspection image Method. A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
In at least one of before and after the electromagnetic wave or charged particle beam irradiation when acquiring the test image, the corresponding portion or the electron beam irradiated with an electron beam Ru changing the charged state of the wafer in the vicinity of the inspection image Set parameters related to irradiation conditions ,
Irradiation of the electromagnetic beam or charged particle beam for acquiring the inspection image is performed after the irradiation of the electron beam for acquiring the inspection image is sequentially performed for each row die of the wafer in three rows. The first portion of the wafer is subjected to the irradiation of the first row of dies, and then the previous irradiation of the electron beam and the irradiation of the electromagnetic wave or charged particle beam for obtaining the inspection image are performed on the first row of dies. A method for inspecting a circuit pattern, which is performed sequentially with a sandwich . A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
Irradiation of the electron beam that changes the charged state of the wafer by irradiating an electron beam to or near the corresponding part of the inspection image at least before or after the electromagnetic wave or charged particle beam irradiation when acquiring the inspection image Set parameters related to conditions ,
After the irradiation of the electromagnetic wave or the charged particle beam for acquiring the inspection image, the inspection image was acquired on the one-line die of the wafer just before the irradiation of the electromagnetic wave or the charged particle beam for acquiring the inspection image Irradiation of the electromagnetic wave or charged particle beam to acquire the inspection image of the next row die of the wafer that has been irradiated with the electron beam and then irradiated with the electromagnetic wave or charged particle beam for acquiring the inspection image. A method for inspecting a circuit pattern, characterized by sequentially repeating the operation of performing the steps. A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
Irradiation of the electron beam that changes the charged state of the wafer by irradiating an electron beam to or near the corresponding part of the inspection image at least before or after the electromagnetic wave or charged particle beam irradiation when acquiring the inspection image Set parameters related to conditions,
After the irradiation of the electromagnetic wave or charged particle beam for acquiring the inspection image is sequentially performed on the two-row dies of the wafer, the row of the wafer subjected to irradiation of the electromagnetic wave or charged particle beam for acquiring the previous inspection image The die is irradiated with the electron beam after obtaining the inspection image , and then the electromagnetic wave or charged particle beam is irradiated to obtain the later inspection image. Irradiation of the electron beam or charged particle beam to be acquired and irradiation of the electron beam to the row die of the wafer where the electromagnetic wave or charged particle beam was acquired to acquire the inspection image immediately before the irradiation A method for inspecting a circuit pattern, characterized by sequentially repeating the operation of performing the steps. A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
Irradiation of the electron beam that changes the charged state of the wafer by irradiating an electron beam to or near the corresponding part of the inspection image at least before or after the electromagnetic wave or charged particle beam irradiation when acquiring the inspection image Set parameters related to conditions,
After irradiation of advance the electron beam to obtain the inspection image of a row die before Symbol wafer, the irradiation of the electromagnetic wave or the irradiation of the charged particle beam the pre of the electron beam to obtain the inspection image Irradiation of the electromagnetic wave or charged particle beam for acquiring the inspection image to the single row die of the wafer immediately before performing, and then irradiation of the electromagnetic wave or charged particle beam for acquiring the inspection image of the single row die of the wafer After the irradiation of the electron beam after obtaining the inspection image on the immediately preceding row die, the prior electron beam is applied to the next row die of the wafer that has been irradiated with the advance electron beam. inspection method of a circuit pattern, wherein the Repetitive Rikae score an operation of performing irradiation. A circuit pattern inspection method for irradiating a wafer surface on which a circuit pattern is formed with an electromagnetic wave or a charged particle beam, and detecting defects in the circuit pattern from an inspection image obtained based on a signal generated from the wafer by the irradiation. And
Irradiation of the electron beam that changes the charged state of the wafer by irradiating an electron beam to or near the corresponding part of the inspection image at least before or after the electromagnetic wave or charged particle beam irradiation when acquiring the inspection image Set parameters related to conditions,
Were successively subjected to irradiation of advance the electron beam to obtain the inspection image of the two rows die before Symbol wafer, the electromagnetic wave or the irradiation of the charged particle sagittal before said pre-obtaining said inspection image done in a row die before Symbol wafer was irradiation of the electron beam, followed by the previous article prior to irradiation the advance in a row die of the next of the wafer of a row die of the wafer was carried out of the electron beam inspection method of a circuit pattern, wherein the score Rikae Repetitive operation of performing irradiation of the electron beam. 7. The electromagnetic wave or charge according to claim 1, wherein parameters relating to an acceleration voltage, an electron dose, and an internal electromagnetic field of the electron beam generation in at least one of before and after acquiring the inspection image are parameters for acquiring the inspection image. A method for inspecting a circuit pattern, wherein the particle beam is an electron beam and is different from parameters relating to an acceleration voltage, an electron dose and an internal electromagnetic field for generating the electron beam . In any one of Claims 1-7, the said electromagnetic wave or charged particle beam with which the parameter of the irradiation width and irradiation speed of the said electron beam in at least one before and after acquiring the said test | inspection image acquires the said test | inspection image is an electron beam. The circuit pattern inspection method is characterized by being different from the parameters of the irradiation width and irradiation speed of the electron beam . In any one of Claims 1-8, the irradiation direction of the said electron beam performed in at least one before and after acquiring the said test | inspection image, and the said electromagnetic wave or charged particle beam which acquires the said test | inspection image are electron beams, A circuit pattern inspection method characterized by being different from an electron beam irradiation direction .

Images