Scanning electronic microscope

[Detailed Description of the Invention]

[Application of the Invention] The present invention relates to suitable scanning electron microscope to use it for photography of charge 9 and the sample that is easy to carry out especially a charge rise at scanning electron microscope. [Background of the Invention] Although the conventional scanning electron microscope is observable without a Mostly charge rise in quick scan speed observation to the sample which is comparatively easy to carry out a charge rise, in order to use the scan with many late scan speeds and scanning lines to photography, there is a fault that photography is impossible without a charge rise. [Objects of the Invention] The object of the present invention is to provide the scanning electron microscope which can perform good photography to the photography of a sample which is comparatively easy to carry out a charge rise. [Summary of the Invention] In the present invention, a jump scan of a scanning line is carried out to photography of a sample image. Therefore, it can be made to perform photography of a sample which is comparatively easy to carry out a charge rise without a charge rise. As for the sweep rate which displays an image, in scanning electron microscope, it is common that many kinds are prepared. The quickest sweep is TV speed and a sweep of interim speed is 0.5 second ~ 2 seconds/frame. A sweep rate (usually 50 seconds ~ 100 seconds/(frame)) late for the improvement in 8/N of the image obtained in photography is used. Although photography may also be possible using a quick sweep rate, since S/N of the image obtained is bad, when special, all the Except are not used. The case where it investigates with all the sample (for example, semiconductor sample) scanning electron microscopes which are comparatively easy to carry out charge amplifier is considered. A comparatively quick sweep rate is used on the relation for which image observation uses the afterimage of a cathode-ray tube. In this case, since a sweep of the electron beam on a sample is quick, in an observation image, Naya and '-rise do not appear easily. however, inside, if I hear that a photograph of this is taken and it changes to a late sweep rate, a charge rise will appear in an image in many cases. If a photograph is taken with a quick sweep rate in order to cancel this, only the bad photograph of S/N will be acquired. It is made to be possible [ photography of the present invention ] in S/N as S/N obtained with the late conventional sweep rate also with Natural same without a charge rise to the photography of a sample which is comparatively easy to carry out charge amplifier. [Example] One example of the present invention is described in detail below. In Drawing 1, it is thinly extracted with Shigeko line 2H1 convergent lens 3 and object lens 6 which were emitted from electronic mirror 1, and Connect a focus on sample 7. At this time, electron beam 2 is scanned in two dimensions in sample 7 top by deflection coil 4 (it is made for the section of electron beam 2 by which non-point amendment coil 5 is Connect(ed) in a focus on sample 7 to serve as a perfect circle). boil the signal (usually secondary electron signal) which occurs from sample 7 by electron irradiation signal detector 8 -- Si capture is carried out, and it is changed into an electric signal, it is opened to traffic amplifier 9, and is sent to a cathode-ray tube (cathode-ray tube 10 for observation, cathode-ray tube 11 for photography) as an intensity modulation signal. By the way, the sweep wave (a level sweep wave and a perpendicular sweep wave) from sweep signal generator 13 or 14, Since it 19t- Lets it pass with deviation amplifier 17 and is sent to deflection coil 4 and the deflection coil of a cathode-ray tube, Imagery (usually secondary electron image) will be obtained by the luminosity based on [ in a sweep of the sweep on sample 7, cathode-ray tube 10.11, and A ] the detection signal from sample 7 in a synchronized sweep, and 9 and cathode-ray tube 10.11. magnification setting machine 18 should have a role into which decrease proportionally thick To of the sweep wave sent to deflection coil 4-like, that is, it makes the field of a sweep of electron beam 2 on sample 7 change, and be elaborate -- be alike -- the magnification of the image obtained by the Si cathode-ray tube 10.11 is changed. Camera 12 for photography is attached to cathode-ray tube 11 for photography, and a photograph of the image obtained is taken to it. Usually photography is performed to an one-frame sweep. In this case, the method which opens 7 Yuta of camera 2 only during an one-frame sweep of photography, There is a method (in the case of a pond, it does not indicate to cathode-ray tube 11 by an image, applying direct-current blanking) which always opens 7 Yanota of camera 12 and displays an image only during an one-frame sweep of photography of cathode-ray tube 11. In these days, the latter method is becoming in use from the point of reinforcement of cathode-ray tube 11. In Drawing 1 which is one example of the present invention, it is an example in this method. Sweep signal generator 13 is used at the time of observation of an image. From now on, a sweep wave (a level sweep wave and a perpendicular sweep wave) and a trigger signal are emitted. A trigger signal is sent to blanking circuit 15, and retrace line elimination of cathode-ray tube 10 is performed. On the other hand, sweep signal generator 14 is used at the time of photography of an image. A sweep wave (a level sweep wave and a perpendicular sweep wave) and a trigger signal are emitted, a trigger signal is sent to PUBLAN young circuit 15 from now on, and retrace line elimination of cathode-ray tube 11 is performed. However, when cathode-ray tube 11 does not take a photograph, it differs in that the Or Si image is not displayed for direct-current blanking. The perpendicular sweep wave of sweep signal generator 14 used at the time of photography has come to be able to perform jump sweeps more arbitrary than the exterior. Usually, if the selection switch is formed, for example, it unites with the scale of 3 jump sweep, a perpendicular sweep will perform 3 jump sweep. By the signal of a photograph start (photography start) of photograph mode setting machine 16, sweep signal generator 14 for photography starts operation, and the sweep wave from sweep signal generator 13 for image observation is divided in circuit. That is, the sweep wave from sweep signal generator 14 will be sent to deflection coil 4 and the deflection coil of a cathode-ray tube through deviation amplifiers 17 and 19 by the signal of a photograph start. On the other hand, direct-current blanking currently impressed to cathode-ray tube 11 for photography is also removed by the signal of a photograph start, and an image comes to be displayed on cathode-ray tube 11. Of course, as for blanking of retrace line elimination, it is natural that the Up \ continuation of is done. After the substantial one-frame sweep (3 jump sweep four perpendicular sweeps) by jump sweep is completed after a photograph start, while direct-current blanking starts B pole Wll for photography and stopping an image display, Sweep signal generator 14 will be divided in circuit, and sweep signal generator 13 will be connected in circuit. The same image as a photograph start or before is displayed on cathode-ray tube 10 for upsilon observation by this. The sweep wave at the time of photography 3 jump K By Drawing 2 and the example of a sweep of a cathode-ray tube are shown. Since an arbitrary jump sweep can be performed at the time of photography according to the example of Lol of the present invention, it is effective in the ability to perform photography of an image without a charge rise. [Effect of the Invention] as opposed to photography of a sample which is comparatively easy to carry out a charge rise in the present invention -- a jump sweep -- all -- To do -- ., Therefore, it is effective in the ability to perform photography without a charge rise.

[Brief Description of the Drawings]

The abbreviated Gland figure where Drawing 1 illustrates the principle of operation of the present invention, and Drawing 2 are figures showing an example of the jump sweep at the time of photography. 13.14 ... sweep signal generator, 15 ... blanking circuit, 16 ... 7 Otho mode setting machine, 17.19 ... deviation amplifier, 18 ... magnification setting machine.