1. A charged particle beam device comprising:
a charged particle source; and
an optical charged particle system which focuses a charged particle beam emitted from the charged particle source to scan the charged particle beam on a sample,
the device further comprising:
a control unit which forms a bright-field image or a back-scattered electron image and a dark-field image based on a transmission electron scattered in the sample or an electron scattered back from the sample,
wherein the control unit compares the bright-field image or the back-scattered electron image with the dark-field image to calculate a correlation between the bright-field image or the back-scattered electron image and the dark-field image.
2. The charged particle beam device according to claim 1, wherein the control unit judges whether or not a correlation value between the bright-field image or the back-scattered electron image and the dark-field image is below a threshold value.
3. The charged particle beam device according to claim 2, wherein the control unit judges that the dark-field image is appropriate, in a case where the correlation value is below the threshold value.
4. The charged particle beam device according to claim 2, wherein the control unit judges that the dark-field image is inappropriate, in a case where the correlation value is above the threshold value.
5. A computer program product for use in a control unit which receives a signal based on a transmission electron andor a back-scattered electron detected by a charged particle beam device to form a bright-field image or a back-scattered electron image and a dark-field image of a sample, the computer program product comprising:
a sequence to compare the bright-field image or the back-scattered electron image with the dark-field image to calculate a correlation between the images.
6. A sample image forming method which scans a charged particle beam on a sample to form a bright-field image or a back-scattered electron image and a dark-field image of the sample based on an electron transmitted through the sample, the method comprising the steps of:
comparing the formed bright-field image or the back-scattered electron image with the dark-field image to calculate a correlation between the images; and
adjusting optical conditions of the charged particle beam, in a case where the calculated correlation value is above a threshold value.
7. A charged particle beam device comprising:
a charged particle source; and
an optical charged particle system which focuses a charged particle beam emitted from the charged particle source to scan the charged particle beam on a sample,
the device further comprising:
a control unit which forms a dark-field image based on a transmission electron scattered in the sample,
wherein the control unit compares reference information registered in the control unit with the dark-field image to judge whether or not the dark-field image has a predetermined contrast.
8. The charged particle beam device according to claim 7, wherein the reference information is a bright-field image formed by detecting the electron transmitted through the sample, a back-scattered electron image formed by detecting a back-scattered electron scattered back from the sample, or sample information input by an input unit which inputs information into the control unit.
9. The charged particle beam device according to claim 7, wherein the control unit compares the dark-field image with the reference information to judge whether or not the dark-field image has the predetermined contrast with respect to the reference information.
10. A charged particle beam device comprising:
a charged particle source; and
an optical charged particle system which focuses a charged particle beam emitted from the charged particle source to scan the charged particle beam on a sample,
the device further comprising:
a control unit which forms a dark-field image based on a transmission electron scattered in the sample or an electron scattered back from the sample,
wherein the control unit stores a scattering simulation result of the transmission electron.
11. The charged particle beam device according to claim 10, wherein the control unit adjusts acquisition conditions of a dark-field signal based on the scattering simulation result.
12. The charged particle beam device according to claim 10, wherein the control unit estimates a scattering angle of the electron transmitted through constituting elements in a depth direction and a transmission electron intensity per unit solid angle of the scattering angle based on the constituting elements of the sample and device conditions.
13. The charged particle beam device according to claim 10, wherein the control unit compares signal intensities of the constituting elements with each other to thereby predict a contrast of the dark-field image.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A level shifter comprising:
a current generator connected between a first high potential terminal and a first low potential terminal and configured to generate a first current at a first output line;
a current switch connected between a second high potential terminal and a second low potential terminal, the current switch configured to receive the first current with a higher current supply capacity than the current generator and pass the first current or cut off the first current in accordance with an input signal; and
a protection circuit connected to the first output line between the current generator and the current switch, the protection circuit configured to limit an electric potential of the first output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal.
2. The level shifter according to claim 1, wherein the current switch makes an electric potential of an output terminal of the current generator a low level or a high level higher than the low level.
3. The level shifter according to claim 1, wherein
an electric potential of the first high potential terminal is not less than an electric potential of the second high potential terminal, and
the protection circuit limits an electric potential of the first output line to which the current generator outputs the first current to not less than an electric potential of the first low potential terminal.
4. The level shifter according to claim 1, wherein the current switch includes a current mirror.
5. The level shifter according to claim 1, wherein the current generator includes a resistor connected between the first high potential terminal and the first low potential terminal.
6. The level shifter according to claim 1, wherein
an electric potential of the second high potential terminal is not less than an electric potential of the first high potential terminal and
the protection circuit limits an electric potential of the first output line to which the current generator outputs the first current to not more than an electric potential of the first high potential terminal.
7. The level shifter according to claim 1, wherein
the current generator includes:
a second output line configured to generate and output a second current;
a first transistor connected between the first high potential terminal or the first low potential terminal and the first output line and configured to turn ON or OFF in accordance with an electric potential of the second output line; and
a second transistor connected between the first high potential terminal or the first low potential terminal and the second output line and configured to turn ON or OFF in accordance with an electric potential of the first output line,
the current switch further receives the second current, the current switch passes the first current and cuts off the second current or the current switch cuts off the first current and passes the second current in accordance with an input signal, and
the protection circuit limits an electric potential of the second output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal.
8. The level shifter according to claim 7, wherein
the first transistor turns OFF after a specified period from when it has turned ON in accordance with an electric potential of the second output line and
the second transistor turns OFF after the specified period from when it has turned ON in accordance with an electric potential of the first output line.
9. The level shifter according to claim 7, wherein
the first transistor connected between the first high potential terminal and the second output line turns ON when an electric potential of the second output line is a low level and
the second transistor connected between the first high potential terminal and the first output line turns ON when an electric potential of the first output line is a low level.
10. A controller comprising:
a level shifter including:
a current generator connected between a first high potential terminal and a first low potential terminal and configured to generate a first current at a first output line;
a current switch connected between a second high potential terminal and a second low potential terminal and configured to receive the first current with a larger current supply capacity than the current generator and pass the first current or cut off the first current in accordance with an input signal; and
a protection circuit connected to the first output line between the current generator and the current switch and configured to limit an electric potential of the first output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal;
a PWM circuit connected between the second high potential terminal and the second low potential terminal and configured to produce a PWM signal as the input signal of the level shifter;
a first switch element connected to the first output line of the level shifter and configured to be controlled to ON or OFF based on an electric potential of the first output line; and
a second switch element connected in series to the first switch element and configured to be controlled to ON or OFF by the PWM circuit.
11. The controller according to claim 10, wherein the current switch makes an electric potential of an output terminal of the current generator a low level or a high level higher than the low level.
12. The controller according to claim 10, wherein
an electric potential of the first high potential terminal is not less than an electric potential of the second high potential terminal, and
the protection circuit limits an electric potential of the first output line to which the current generator outputs the first current to not less than an electric potential of the first low potential terminal.
13. The controller according to claim 10, wherein
an electric potential of the second high potential terminal is not less than an electric potential of the first high potential terminal, and
the protection circuit limits an electric potential of the first output line to which the current generator outputs the first current to not more than an electric potential of the first high potential terminal.
14. The controller according to claim 10, wherein
the current generator includes:
a second output line configured to generate and output a second current;
a first transistor connected between the first high potential terminal or the first low potential terminal and the first output line and configured to turn ON or OFF in accordance with an electric potential of the second output line; and
a second transistor connected between the first high potential terminal or the first low potential terminal and the second output line and configured to turn ON or OFF in accordance with an electric potential of the first output line,
the current switch further receives the second current, the current switch passes the first current and cuts off the second current or the current switch cuts off the first current and passes the second current in accordance with an input signal, and
the protection circuit limits an electric potential of the second output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal.
15. The controller according to claim 14, wherein
the first transistor turns OFF after a specified period from when it has turned ON in accordance with an electric potential of the second output line and
the second transistor turns OFF after the specified period from when it has turned ON in accordance with an electric potential of the first output line.
16. The controller according to claim 14, wherein
the first transistor connected between the first high potential terminal and the second output line turns ON when an electric potential of the second output line is a low level and
the second transistor connected between the first high potential terminal and the first output line turns ON when an electric potential of the first output line is a low level.
17. A DC-DC converter comprising:
a controller including:
a level shifter including:
a current generator connected between a first high potential terminal and a first low potential terminal and configured to generate a first current at a first output line;
a current switch connected between a second high potential terminal and a second low potential terminal and configured to receive the first current with a larger current supply capacity than the current generator and pass the first current or cut off the first current in accordance with an input signal; and
a protection circuit connected to the first output line between the current generator and the current switch and configured to limit an electric potential of the first output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal;
a PWM circuit connected between the second high potential terminal and the second low potential terminal and configured to produce a PWM signal as the input signal of the level shifter;
a first switch element connected to the first output line of the level shifter and configured to be controlled to ON or OFF based on an electric potential of the first output line; and
a second switch element connected in series to the first switch element and configured to be controlled to ON or OFF by the PWM circuit;
an inductor, one end of the inductor being connected to a connection point between the first switch element and the second switch element;
a smoothing capacitor connected between another end of the inductor and the first low potential terminal or the second low potential terminal; and
a detector connected in parallel to the smoothing capacitor and configured to detect an electric potential of the other end of the inductor and feed it back to the controller.
18. The DC-DC converter according to claim 17, wherein
the current generator includes:
a second output line configured to generate and output a second current;
a first transistor connected between the first high potential terminal or the first low potential terminal and the first output line and configured to turn ON or OFF in accordance with an electric potential of the second output line; and
a second transistor connected between the first high potential terminal or the first low potential terminal and the second output line and configured to turn ON or OFF in accordance with an electric potential of the first output line,
the current switch further receives the second current, the current switch passes the first current and cuts off the second current or the current switch cuts off the first current and passes the second current in accordance with an input signal, and
the protection circuit limits an electric potential of the second output line to not less than an electric potential of the first low potential terminal and not more than an electric potential of the first high potential terminal.
19. The DC-DC converter according to claim 17, wherein
the first transistor turns OFF after a lapse of a specified period from when it has turned ON in accordance with an electric potential of the second output line and
the second transistor turns OFF after a lapse of the specified period from when it has turned ON in accordance with an electric potential of the first output line.
20. The DC-DC converter according to claim 17, wherein
the first transistor is connected between the first high potential terminal and the second output line and is ON when an electric potential of the second output line is a low level and
the second transistor is connected between the first high potential terminal and the first output line and is ON when an electric potential of the first output line is a low level.