Nitrogen trifluoride (NF3) is a colourless, non-flammable and toxic gas which gives a mouldy smell. Nitrogen trifluoride is an etchant and chamber cleaning agent. It is used to remove silicon and other silicon compounds in the semiconductor industry such as solar cells, LCD display and other electronic components. The NF3 breaks down to form fluorine radicals and these are active agents that remove the silicon compounds and other metals. It is widely used to clean plasma enhanced chemical vapor deposition (PECVD) chambers.