Scanning electron microscope, an interface and a method for observing an object within a non-vacuum environment

A scanning electron microscope comprising:

• an electron beam source positioned in a vacuum environment;
• the electron beam source is adapted to generate an electron beam;
• an interface between the vacuum environment and a non-vacuum environment in which an object is positioned, the interface comprises an aperture array sealed by an ultra thin membrane that is substantially transparent to the electron beam and withstands a pressure difference between the vacuum environment and the non-vacuum environment;
• an object holder;
• a scanner that scans a region of the object with the electron beam while the object is located below the object holder;
• wherein the electron beam passes through an aperture of the aperture array, passes through the ultra thin membrane, and passes through the object holder;
• a detector that detects particles generated in response to an interaction between the electron beam and the object and determining a distance between the object and the ultra-thin membrane in response to detected particles.

A method for observing an object that is positioned in a non-vacuum environment, the method comprises:

• illuminating an area of an object with an electron beam;
• wherein the electron beam is generated in the vacuum environment and passes through an aperture of an aperture array and passes through an ultra thin membrane that seals the aperture;
• wherein the ultra thin membrane withstands a pressure difference between the vacuum environment and the non-vacuum environment;
• detecting particles generated in response to an interaction between the electron beam and the object;
• and
• determining a distance between the object and the ultra thin membrane in response to detected particles.

A scanning electron microscope comprising:

• an electron beam source positioned in a vacuum environment;
• the electron beam source is adapted to generate an electron beam;
• optics configured to direct the electron beam towards an area of the object;
• an interface between the vacuum environment and a non-vacuum environment in which an object is positioned, the interface comprises an aperture array sealed by an ultra thin membrane that is substantially transparent to the electron beam and withstands a pressure difference between the vacuum environment and the non-vacuum environment;
• at least one detector that detects particles generated in response to an interaction between the electron beam and the object;
• and
• a controller configured to determine a distance between the object and the ultra thin membrane in response to detection signals generated by the at least one detector.

A method for aligning an electron beam and an aperture of an aperture array, the method comprises:

• obtaining an image of a first area of the aperture array;
• wherein the first area comprises multiple apertures of the aperture array;
• calculating a spatial relationship between a selected aperture of the multiple apertures and a reference location within the first area;
• aligning an electron beam with the reference location in response to the spatial relationship;
• and
• obtaining an image of a region of an object that is positioned in a non-vacuum environment;
• wherein the obtaining comprises scanning the region by an electron beam that is generated in a vacuum environment, passes through the selected aperture and passes through an ultra thin membrane that seals the selected aperture;
• wherein the ultra thin membrane withstands a pressure difference between the vacuum environment and the non-vacuum environment.

A scanning electron microscope comprising:

• an electron beam source positioned in a vacuum environment;
• the electron beam source is adapted to generate an electron beam;
• an interface between the vacuum environment and a non-vacuum environment in which an object is positioned, the interface comprises an aperture array sealed by an ultra thin membrane that is substantially transparent to the electron beam and withstands a pressure difference between the vacuum environment and the non-vacuum environment;
• optics configured to scan, with an electron beam, a first area of the aperture array and scan a second area of the aperture array;
• wherein the first area comprises multiple apertures of the aperture array;
• wherein the second area is smaller than the first area and comprises a selected aperture;
• at least one detector that detects particles generated in response to an interaction between the electron beam and at least one entity out of the interface and the object;
• and
• a controller configured to:
• calculate a spatial relationship between a selected aperture of the multiple apertures and a reference location within the first area;
• and
• control an alignment of the electron beam with the reference location in response to the spatial relationship.