I did a stint back in the day at the IBM Cottle road site sputtering hard disks. All the tools had roughing pumps that would bring the tool to near vacuum before the turbo pumps would kick in as anything even remotely close to atmosphere would just rip the blades apart. Then the older huge tool, the Ulvac had a cryo-pump which was just a big chamber that would cool a sponge to 20 kelvin and molecules would just come in contact and slow down...