Charged particle beam device and vibration-suppressing mechanism
Provided are a vibration-suppressing mechanism that has excellent maintainability and can effectively control vibration of a column, and a charged particle beam device using the same. This charged particle beam device comprises: a sample chamber for accommodating a sample that will serve as an object to be observed therein; a column that is disposed on an upper portion of the sample chamber and irradiates and scans the sample with a charged particle beam generated by a charged particle source; and a vibration-suppressing mechanism that is removably provided to the column, said particle beam device being characterized in that the vibration-suppressing mechanism includes a stator affixed to the column, an annular mover that is supported so as to be movable in a direction orthogonal to the axial direction of the column, a plurality of actuators that cause the mover to vibrate in the direction orthogonal to the axial direction of the column, a plurality of vibration sensors affixed to the stator, and a controller that controls the actuators according to output signals from the vibration sensors.
1 . A charged particle beam device comprising:
a sample chamber for accommodating a sample that will serve as an object to be observed therein;
a column that is disposed on an upper portion of the sample chamber and irradiates and scans the sample with a charged particle beam generated by a charged particle source; and
a vibration-suppressing mechanism that is removably provided to the column,
wherein the vibration-suppressing mechanism includes
a fixing ring attached to an upper portion of the column,
a stator affixed to the fixing ring via a spacer, such that an entirety of the stator is disposed above the fixing ring and the upper portion of the column, wherein an axial direction of the spacer is parallel to an axial direction of the column,
an annular mover that is supported so as to be movable in a direction orthogonal to the axial direction of the column,
a plurality of actuators that cause the mover to vibrate in the direction orthogonal to the axial direction of the column,
a plurality of vibration sensors affixed to the stator, and
a controller that controls the actuators according to output signals from the vibration sensors,
wherein the mover is supported by an elastic member having elasticity with respect to the stator in an operation direction of the actuators, and
wherein the actuators cause the mover to vibrate with respect to the stator to attenuate vibration generated in the column.
2 . The charged particle beam device according to claim 1 , wherein, when the column is viewed from the axial direction, the mover is disposed inside the stator, and the actuators are provided on the stator from an outside.
3 . The charged particle beam device according to claim 1 , wherein, when the column is viewed from the axial direction, the mover is disposed outside the stator, and the actuators are provided on the mover from an outside.
4 . The charged particle beam device according to claim 1 , wherein each of the actuators includes
a piezoelectric element,
a case for protecting the piezoelectric element by applying a preload to the piezoelectric element, and
a tip end portion that protrudes from one end of the case and outputs displacement, and
the tip end portion stretches and contracts by the piezoelectric element.
5 . The charged particle beam device according to claim 1 , wherein a center of gravity of the mover is located on a substantially intersection point of thrust lines of the plurality of actuators.
6 . The charged particle beam device according to claim 1 , wherein the stator includes a recessed portion in which the elastic member is disposed.
7 . The charged particle beam device according to claim 6 , wherein the elastic member is disposed in the operation direction of the actuators between an outer periphery of the stator and an outer periphery of the mover.
8 . A vibration-suppressing mechanism that is removably provided to a column of a charged particle beam device and suppresses vibration generated in the column, the vibration-suppressing mechanism comprising:
a fixing ring attached to an upper portion of the column;
a stator affixed to the fixing ring via a spacer, such that an entirety of the stator is disposed above the fixing ring and the upper portion of the column, wherein an axial direction of the spacer is parallel to an axial direction of the column;
an annular mover that is supported so as to be movable in a direction orthogonal to an axial direction of the column;
a plurality of actuators that cause the mover to vibrate in the direction orthogonal to the axial direction of the column;
a plurality of vibration sensors affixed to the stator; and
a controller that controls the actuators according to output signals from the vibration sensors;
wherein the mover is supported by an elastic member having elasticity with respect to the stator in an operation direction of the actuators, and
wherein the actuators cause the mover to vibrate with respect to the stator to attenuate vibration generated in the column.
9 . The vibration-suppressing mechanism according to claim 8 , wherein the mover is disposed inside the stator, and the actuators are provided on the stator from an outside.
10 . The vibration-suppressing mechanism according to claim 8 , wherein the mover is disposed outside the stator, and the actuators are provided on the mover from an outside.
11 . The vibration-suppressing mechanism according to claim 8 , wherein each of the actuators includes
a piezoelectric element,
a case for protecting the piezoelectric element by applying a preload to the piezoelectric element, and
a tip end portion that protrudes from one end of the case and outputs displacement, and
the tip end portion stretches and contracts by the piezoelectric element.
12 . The vibration-suppressing mechanism according to claim 8 , wherein a center of gravity of the mover is located on a substantially intersection point of thrust lines of the plurality of actuators.
13 . The vibration-suppressing mechanism according to claim 8 , wherein the stator includes a recessed portion in which the elastic member is disposed.
14 . The vibration-suppressing mechanism according to claim 13 , wherein the elastic member is disposed in the operation direction of the actuators between an outer periphery of the stator and an outer periphery of the mover.