Hi all,

I am having problem with spin coater. At first there were some photoresist
going into the chuck all the way to the bottom so the program stopped
automatically after a couple of seconds of running. Also the platform was
very hard to rotate by hand. After I cleaned the pathway which has the
photoresist, the platform moves freely but the vaccum is showing
insufficient value. Is there something blocking the vacuum
somewhere? How could I possibly check the block?

Thank you very much!

Jia