Sample inspecting device

Abstract

Abstract PURPOSE:To remove dust from a sample automatically by using a combination of a dust detecting technique with radiation of rays of light and a gas spraying technique. CONSTITUTION:A light source 1, diaphragms 2, 5, lenses 4, 6, a light detector 7 and a nozzle 11 are arranged above a movable block 9, and the detector 7 is connected to a valve 13 through an amplifier 12 and a valve-opening signal generating circuit 14. In this arrangement, the light 3 emitted from the light source 1 is condensed by the diaphragms 2, 5 and lenses 4, 6 to be radiated onto a sample 8, such as a mask, placed on the movable table 9. When dust sticks to the sample 8, the light is scattered and dected by the light detector 7. An electric signal outputted from the light detector 7 representing the scattered light is applied to the valve- opening signal generating circuit 14. When the signal inputted into the circuit 14 is larger than the reference electric signal, the valve 13 is opened. As a result, a compressed gas is jetted from the nozzle 11 to that portion of the sample 8 which is irradiated by the light, so that the dust sticking to the mentioned portion of the sample 8 is blown off.

Inventors

• 👤 Kazumitsu Nakamura

Bibliographic Details