| 摘要 |
<p>PURPOSE:To accurately align the surface of a sample to be inspected on the focus position of a detection optical system with high frequency responsiveness by providing a counter spring and deviating an area irradiated with 1st light used for a pattern inspection from the area irradiated with 2nd light used for detecting the positional deviation. CONSTITUTION:A device is provided with the counter spring 30 which is connected between the lens barrel 24 and a fixing part 29 and for balancing the weight of the lens barrel 24. And also, the optical system for detection constituted of beam benders 43a,43b and a lens 44a, etc., and the optical system for detection constituted of beam benders 43c, 43d and a lens 44b, etc., are arranged so that they may be slightly deviated form each other at the opposite position symmetrical to the central axis of the lens barrel 24. Then, a load which is put on a driving member 31 can be reduced, the measurement difference in detecting the positional deviation which is caused by optical interference by each other and diffused external light can be reduced by deviating the area irradiated with the position detecting light from the area irradiated with the pattern inspecting light. Thus, the surface of the sample to be inspected can be accurately and automatically aligned on the focus position of the detection optical system with the high frequency responsiveness.</p> |
