SCANNING TRANSMISSION ELECTRON MICROSCOPE WITH VARIABLE AXIS OBJECTIVE LENS AND DETECTIVE SYSTEM

摘要

The present invention provides a scanning transmission electron microscope (STEM). In the STEM, a specimen is sandwiched between a variable axis objective lens and a variable axis collection lens. The axis of the collection lens varies along with the variation of the objective lens axis in a coordinated manner. The STEM of the invention exhibits technical merits such as large scanning field, high image resolution across the entire scanning field, and high throughput, among others.

主权项

1. A scanning transmission electron microscope (STEM) comprising:
an electron source for emitting a primary electron beam; a detector for receiving the electron beam, wherein a reference axis is defined by the straight line connecting the electron source and the detector; a specimen plane located between the electron source and the detector, wherein the reference axis is perpendicular to the specimen plane; a first redirector that redirects the electron beam to a path not in alignment with the reference axis; a lens module comprising a variable axis objective lens and a variable axis collection lens, between which is the specimen plane, wherein the variable axis objective lens is located between the electron source and the specimen plane for focusing the electron beam redirected by said first redirector to a focusing spot on the specimen plane, and wherein the variable axis collection lens is located between the specimen plane and the detector for collecting the electron beam that has passed through the specimen plane; and a second redirector that redirects the electron beam that has been collected by the variable axis collection lens back to a path in alignment with the reference axis, before the beam reaches the detector.