Nanotechnology: A Maker's Course Week 5

Why is a vacuum chamber typically kept under vacuum when not in use?

It keeps the chamber cleaner than leaving it filled with air

Why do the cooling fins in a cryopump have a large surface area?

Larger surface area provides more room for trapping air molecules, which improves pumping

A cryo-pump is used in combination with a rough pump to achieve high vacuum.

True

A cryopump will eventually become saturated with air molecules and pumping efficiency will degrade.

True

During sputter deposition, increasing or decreasing sputter power too quickly can cause the target material to crack.

True

It is necessary to rough pump a vacuum chamber before pumping with a high vacuum pump.

True

Why do we often use a tungsten boat to hold gold during thermal evaporation?

Tungsten has higher melting temperature than gold

The turbo-molecular pump, or simply turbopump, is an example of what type of pump:

a high vacuum pump

In sputter deposition, the function of the plasma is to:

generate energetic atoms that remove target material