Method and apparatus for fine movement of specimen stage of electron microscope

A method for fine movement of a specimen stage of an electron microscope, comprising the steps of:

• setting a value of enlargement magnification, M, of said electron microscope;
• forming on a viewing screen an enlarged image, magnified M times, of a specimen mounted on said specimen stage;
• operating a manipulation unit means that instructs movement of said specimen stage and therefore said enlarged image as viewed on said viewing screen, instructed movement of said specimen stage is in at least the X direction or the perpendicular Y direction on a plane substantially perpendicular to the optical axis of the optical axis of said electron microscope;
• delivering at least a pulse signal PX2 or a pulse signal PY2 which accords with the amount of movement instructed to be caused by said manipulation unit means, respectively, in said X direction and said Y direction;
• moving said specimen stage in at least said X or Y directions in accordance with said pulse signal PX2 and said pulse signal PY2;
• delivering at least a pulse signal PX1 or a pulse signal PY1 which accords with the distance said specimen stage moves in said X or Y directions, respectively;
• and
• stopping movement of said specimen stage when the relation represented by PX2.multidot.K/M=PX1 and the relation represented by PY2.multidot.K/M=PY1 are satisfied, where K is a constant.

A method for fine movement of a specimen stage of an electron microscope, comprising the steps of:

• setting a value of enlargement magnification, M, of said electron microscope;
• forming on a viewing screen an enlarged image, magnified M times, of a specimen mounted on said specimen stage;
• operating a manipulation unit means that instructs movement of said specimen stage so said enlarged image as viewed on said viewing screen, instructed movement of said specimen stage is in at least the X direction or the perpendicular Y direction on a plane substantially perpendicular to the optical axis of said electron microscope;
• delivering, within a predetermined interval of time, at least a pulse signal PX2 or a pulse signal PY2 which accords with the amount of movement instructed to be caused by said manipulation unit means, respectively, in said X direction and said Y direction;
• moving said specimen stage in at lease said X or Y direction in accordance with said pulse signal PX2 and said pulse signal PY2;
• delivering at least a pulse signal PX1 or a pulse signal PY1 which accords with the distance said specimen stage moves in said X or Y directions, respectively;
• continuing movement of said specimen stage until the relation represented by PX2.multidot.K/M=PX1 and the relation represented by PY2.multidot.K/M=PY1 are satisfied, where K is a constant;
• and operating said manipulation unit means repetitively.

A method for fine movement of a specimen stage of an electron microscope, comprising the steps of:

• moving said specimen stage to a reference position;
• setting a value of enlargement magnification, M, of said electron microscope;
• forming on a viewing screen an enlarged image, magnified M times, of a specimen mounted on said specimen stage;
• operating a manipulation unit means that instructs movement of said specimen stage so said enlarged image as viewed on said viewing screen, instructed movement of said specimen stage is in at least the X direction or the perpendicular Y direction on a plane substantially perpendicular to the optical axis of said electron microscope;
• detecting outputs from said manipulation unit means;
• moving said specimen stage in at least the X or Y directions in accordance with said detected outputs of said manipulation unit means;
• detecting and displaying distance moved from said reference position of said specimen stage;
• delivering at least a pulse signal PX1 or a pulse signal PY1 which accords with the distance said specimen stage has moved in said X or Y directions, respectively;
• and
• operating said specimen stage moving step until the relations represented by PX2.multidot.K/M=PX1 and the relation represented by PX2.multidot.K/M=PY1 are satisfied, where K is a constant.