Patent ID: 8729468

Claim:
Microelectronic substrate inspection equipment comprising: a helium gas container containing helium gas; a helium ion generator that is configured to convert the helium gas into helium ions; a wafer stage which is disposed in a path of the helium ions and is configured for placing a microelectronic substrate to be inspected thereon; a secondary electron detector which is disposed adjacent the wafer stage and is configured to detect electrons generated from the substrate; a compressor which is configured to receive first gaseous nitrogen from a continuous nitrogen supply device and to compress the received first gaseous nitrogen into liquid nitrogen; a liquid nitrogen dewar which is connected to the compressor and is configured to store the liquid nitrogen; and a cooling device which is coupled to the helium ion generator and configured to cool the helium ion generator by vaporizing the liquid nitrogen received from the liquid nitrogen dewar into second gaseous nitrogen.