| 摘要 |
Control of x-ray beam spot size is provided to control effective spot size and angle information of radiation on a target area on the surface of a sample. Control of x-ray beam spot size includes the steps of: directing a radiation beam(27) to impinge on a target area(28) on the surface of a sample(22) along a beam axis at each of a plurality of different elevation angles in sequence; determining, for each of the different angles, offset of the beam in a direction transverse to the beam axis; applying a transverse correction to at least one of the beam and the sample to compensate for the offset, while directing the radiation beam to impinge on the target area at each of the different elevation angles; and sensing the radiation(29) scattered from the sample while the beam irradiates the target area at each of the different elevation angles subject to the transverse correction. |
