Abstract: A cleaning process for cleaning a thermal processing apparatus includes: a heating step of heating an interior of a reaction tube at 300° C., and a cleaning step of removing deposits deposited in the thermal processing apparatus. In the cleaning step, a cleaning gas containing fluorine gas, chlorine gas and nitrogen gas is supplied into the interior of the reaction tube heated at 300° C. to remove silicon nitride so to clean an interior of the thermal processing apparatus.

Abstract: A cleaning process for cleaning a thermal processing apparatus includes: a heating step of heating an interior of a reaction tube at 300° C., and a cleaning step of removing deposits deposited in the thermal processing apparatus. In the cleaning step, a cleaning gas containing fluorine gas, chlorine gas and nitrogen gas is supplied into the interior of the reaction tube heated at 300° C. to remove silicon nitride so to clean an interior of the thermal processing apparatus.

Abstract: An unnecessary film is removed by cleaning gas flowing in a treatment vessel 8 for depositing a film on an object W to be processed such as a semiconductor wafer. In this case, the cleaning gas is preheated and activated by the gas heating mechanism 52 and the cleaning gas flows in the treatment vessel 8 in this state. By doing this, an unnecessary film in the treatment vessel made of quartz is removed effectively without damaging the treatment vessel.

Abstract: The method according to the present invention enables to suppress damaging the reaction tubes and the wafer boat made of quarts, when cleaning the reaction vessel after the completion of film forming process for a polysilicon or titanium nitride film, thus the method reduces the running cost. After forming a polysilicon film on the semiconductor wafers, the empty wafer boat is placed in the reaction vessel. The interior atmosphere of the reaction vessel is maintained at temperatures in the range of 700 to 1000° C. A mixed gas prepared by diluting chlorine gas with nitrogen gas is supplied at a predetermined flow rate into the reaction vessel to remove the polysilicon film. A titanium nitride film can also be removed in the same manner.

Abstract: The present invention is directed to a method of etching a compound metal oxide film containing plural kinds of metallic element, such as Ba, Sr, Ti or the like. A first cleaning step employing Cl2 gas is carried out in order to remove alkaline earth metal (Ba, Sr) from the film, then a second cleaning step employing ClF3 gas is carried out in order to remove a metal (Ti) other than the alkaline earth metal from the film. The etching method is applicable not only to the etching process in the semiconductor manufacturing but also to the cleaning process for cleaning the processing vessel for film deposition.

Abstract: An unnecessary film is removed by cleaning gas flowing in a treatment vessel 8 for depositing a film on an object W to be processed such as a semiconductor wafer. In this case, the cleaning gas is preheated and activated by the gas heating mechanism 52 and the cleaning gas flows in the treatment vessel 8 in this state. By doing this, an unnecessary film in the treatment vessel made of quartz is removed effectively without damaging the treatment vessel.