Patent attributes
A plasma cleaning gas for CVD chamber is a gas for cleaning silicon-containing deposits on the surface of a CVD chamber inner wall and the surfaces of members placed inside the CVD chamber after film forming treatment on a substrate by a plasma CVD apparatus. The cleaning gas includes 100% by volume of fluorine gas which gas can generate plasma by electric discharge. When 100% by volume of fluorine gas is plasma-generated by electric discharge and then used as a cleaning gas, an extremely excellent etching rate can be attained and further plasma can be stably generated even in the total gas flow rate of 1000 sccm and at a chamber pressure of 400 Pa. Further, the uniformity of cleaning can be also ensured in the above conditions. Additionally the fluorine gas concentration is 100% so that the apparatus is not complicated and thereby the cleaning gas has excellent practicability.