Cleaning and etching methods and their apparatuses
A cleaning method for removing fats, oils, and silicon small particles, which are conventionally difficult to remove, adhering to devices and carriers used to manufacture a semiconductor wafer or a semiconductor device. An etching method is also disclosed. XeF 2 gas produced by sublimation is made to contact with an object to be cleaned in a vacuum atmosphere so as to decompose and gasify the oils and fats and to remove silicon small particles by etching. Prior to the cleaning, when a trace amount of residual water is left in the vacuum atmosphere, H 2 O reacts with XeF 2 , and HF is produced. For example, a native oxide SiO 2 formed on the surface of silicon small particles can be removed, and XeF 2 directly reacts with silicon, therby enabling etching. The cleaning etching rates are extremely high.
1. A cleaning method comprising the steps of:
causing XeF 2 gas to contact and act on an article containing silicon in a reduced-pressure or vacuum atmosphere containing a required amount of water to remove a SiO 2 film formed on the silicon of the article, and then
causing XeF 2 gas to contact and act on the article in a reduced-pressure atmosphere not containing water or vacuum atmosphere not containing water.
2. The cleaning method according to claim 1 , wherein the XeF 2 gas is supplied continuously in both the step using the atmosphere containing water and the step using the atmosphere not containing water.
3. The cleaning method according to claim 1 , wherein the article to be cleaned is a member of the group consisting of a gas passageway and an inside of a chamber of a semiconductor wafer manufacturing apparatus or a semiconductor device manufacturing apparatus.
4. The cleaning method according to claim 1 , wherein the article to be cleaned is a member of the group consisting of a semiconductor wafer, a semiconductor device, and a carrier thereof.
5. An etching method comprising the steps of:
causing XeF 2 gas to contact and act on an article containing silicon in a reduced-pressure or vacuum atmosphere containing a required amount of water to remove a SiO 2 film formed on the silicon of the article, and then
causing XeF 2 gas to contact and act on the article to be processed in a reduced-pressure atmosphere not containing water or a vacuum atmosphere not containing water.
6. The etching method according to claim 5 , wherein the XeF 2 gas is supplied continuously in both the step with the atmosphere containing water and the step with the atmosphere not containing water.
7. The etching method according to claim 5 , wherein the article to be processed is a silicon wafer.