Patent ID: 7751921

Claim:
A semiconductor deposition apparatus that includes a reaction vessel and is configured to perform a deposition process on substrates in the reaction vessel to fabricate a semiconductor device, said apparatus comprising: a boundary data storage unit that stores boundary data defining a boundary between a normal region and an abnormal region on a biaxial coordinate system, the coordinate system having a first axis and a second axis respectively assigned a first monitoring parameter and a second monitoring parameter that varies according to a correlation with the first monitoring parameter; first and second monitoring means for monitoring the first and second monitoring parameters, respectively; batch size selection means for selecting a batch size which represents the number of substrates processed by a single process in the reaction vessel; judgment means for judging whether a position, on the biaxial coordinate system, of a combination of values of the first and second monitoring parameters respectively obtained by the first and second monitoring means is included in the normal region or in the abnormal region; and abnormality alarming means for alarming that there exists an abnormality in the semiconductor deposition apparatus if the judgment means determines that the position is included in the abnormal region, wherein the first monitoring parameter is a cumulative film thickness which represents the sum of the thickness of films which have been deposited in the reaction vessel, and the second monitoring parameter is an opening of a pressure control valve which is arranged in a vacuum exhaust path to control pressure in the reaction vessel; the boundary data storage unit stores a plurality of boundary data respectively corresponding to different batch sizes; the judgment means is configured to make a judgment based on boundary data corresponding to a selected batch size; and if the judgment means determines that the position is included in the abnormal region, the abnormality alarming means is configured to alarm that the air-tightness of the reaction vessel is insufficient or that cleaning is necessary.