Charged-particle microscopy with image stitching

摘要

A method of producing a composite image of a sample using a charged-particle microscope, the composite image comprising a plurality of sub-images that are stitched together along overlap zones, said method comprising the following steps:- Mounting the sample on a sample holder;- Using a particle-optical column to direct at least one input beam of particulate radiation onto the sample, thereby producing an interaction that causes a plurality of different types of output radiation to emanate from the sample;- Detecting a first type of output radiation and using it to produce:■ A sub-image I_1A of a primary region R_A of the sample;■ A sub-image I_1B of a secondary region R_B of the sample,whereby R_B is adjacent to R_A and overlaps partially therewith, and I_1B has an overlap zone Z₁ with I_1A,which method comprises the following steps:- Detecting a second type of output radiation, different to said first type, and using it to produce:■ A sub-image I_2A of primary region R_A;■ A sub-image I_2B of secondary region R_B,whereby I_2B has an overlap zone Z₂ with I_2A;- Using computer processing apparatus to:■ Elect one of the sub-image pairs (I_1A, I_1B) and (I_2A, I_2B);■ For the sub-image pair thus elected, calculate the relative shift Δ of its two sub-images that is required to bring them into mutual registration, and stitch the two sub-images together after effecting this shift Δ;■ For the other of the sub-image pairs, stitch its two sub-images together on the basis of the same relative shift Δ. ;In an aspect of this method, said computer processing apparatus is used to:- Examine correlation of I1B to I1A within zone Z1;- Examine correlation of I2B to I2A within zone Z2;- Use the outcome of these examinations in performing said election.