ALIGNMENT METHOD

A method of determining the position of an alignment mark (29) on a substrate, the alignment mark (29) comprising a first segment (29a) and a second segment (29b), the method comprising illuminating the alignment mark with radiation, detecting radiation diffracted by the alignment mark and generating a resulting alignment signal. The alignment signal comprises a first component received during illumination of the first segment only (beam profile 35 is on the left), a second component received during illumination of the second segment only (beam profile 35 is on the right), and a third component received during simultaneous illumination of both segments (when the beam passes the boundary between 29a and 29b). The positions of the segments (29a, 29b) are determined using the first component,the second component and the third component of the alignment signal. 种确定对准标记(29)在衬底上的位置的方法，该对准标记(29)包括第段(29a)和第二段(29b)，该方法包括用辐射照射对准标记，检测由对准标记衍射的辐射并且生成作为结果的对准信号。对准信号包括仅在第段照射期间接收的第分量(光束轮廓35在左侧)、在仅第二段的照射期间接收的第二分量(光束轮廓35在右侧)、以及