SAMPLE HEIGHT DETECTION DEVICE AND PATTERN INSPECTION SYSTEM

PROBLEM TO BE SOLVED: To provide a slit-projection-type sample height detection device in which the detection accuracy hardly decreases even when the diffraction angle of primary diffraction light occurring on a sample surface increases.SOLUTION: When the illumination light having passed through a slit opening part OP1, namely an image of the slit opening part OP1, is reduced and projected on a sample S by an objective lens 17, the planar shape of the slit opening part OP1 is set to a shape defined by one rectangle or a shape defined by overlaying a plurality of rectangles on each other on a plane. The length of the short side of the rectangle is set at Mλ/(2 NA) or shorter. Here, M [times] shows the reduction magnification of the image of the slit opening part OP1 by an illumination optical system 10, NA shows the numerical aperture of the objective lens 17, and λ [nm] shows the wavelength of the illumination light coming into the illumination optical system 10.SELECTED DRAWING: Figure 1 【課題】試料面で生じる１次回折光の回折角が広くなっても検出精度の低下が起こり難いスリット投影型の試料高さ検出装置を提供する。【解決手段】スリット開口部ＯＰ１を通過した照明光、つまりスリット開口部ＯＰ１の像を対物レンズ１７で試料Ｓに縮小投影するにあたり、スリット開口部ＯＰ１の平面形状を１つの長方形によって規定される形状、または複数の長方形を平面上で重ね合わせることによって規定される形状にし、かつ、照明光学系１０によるスリット開口部ＯＰ１の像の縮小倍率をＭ［倍］、対物レンズ１７の開口数をＮＡ、照明光学系１０に入射する照明光の波長をλ［ｎｍ］としたときに、上記長方形の短辺の長さをＭλ／（２ＮＡ）以下にする。【選択図】図１