Wafer defect test apparatus, wafer defect test system, wafer test method and fabrication method of a wafer

A wafer defect test system, comprising:

• a monitoring apparatus which monitors a first wafer, a second wafer, and a third wafer being fabricated;
• and
• a computing apparatus connected to the monitoring apparatus,
• wherein the monitoring apparatus monitors the first wafer to generate a first process variable and a second process variable,
• the monitoring apparatus monitors the second wafer to generate a third process variable and a fourth process variable,
• the monitoring apparatus monitors the third wafer to generate a fifth process variable and a sixth process variable,
• the computing apparatus generates a first wafer vector of the first process variable and the second process variable,
• the computing apparatus generates a second wafer vector of the third process variable and the fourth process variable,
• the computing apparatus generates a third wafer vector of the fifth process variable and the sixth process variable,
• the computing apparatus calculates a first Euclidean distance between the first wafer vector and the second wafer vector,
• the computing apparatus calculates a first Cosine distance between the first wafer vector and the second wafer vector,
• the computing apparatus calculates a second Euclidean distance between the first wafer vector and the third wafer vector,
• the computing apparatus calculates a second Cosine distance between the first wafer vector and the third wafer vector,
• the computing apparatus calculates a third Euclidean distance between the second wafer vector and the third wafer vector,
• the computing apparatus calculates a third Cosine distance between the second wafer vector and the third wafer vector,
• the computing apparatus generates a first abnormal wafer index of the first wafer, based on a product of the first Euclidean distance and the first Cosine distance and a product of the second Euclidean distance and the second Cosine distance,
• the computing apparatus generates a second abnormal wafer index of the second wafer, based on the product of the first Euclidean distance and the first Cosine distance and a product of the third Euclidean distance and the third Cosine distance,
• the computing apparatus generates a third abnormal wafer index of the third wafer, based on a product of the second Euclidean distance and the second Cosine distance and the product of the third Euclidean distance and the third Cosine distance, and
• the computing apparatus predicts defective wafers among the first wafer to third wafer, using the first abnormal wafer index to the third abnormal wafer index.

A method for fabricating a wafer, the method comprising:

• fabricating a first wafer, a second wafer and a third wafer different from each other;
• generating a wafer defect prediction model, using the fabricated first wafer and second wafer;
• and
• testing for a defect of the third wafer, using the wafer defect prediction model,
• wherein generating the wafer defect prediction model includes
• monitoring the first wafer to generate a first wafer vector of a first process variable and a second process variable,
• monitoring the second wafer to generate a second wafer vector of a third process variable and a fourth process variable,
• calculating a first Euclidean distance between the first wafer vector and the second wafer vector,
• calculating a first Cosine distance between the first wafer vector and the second wafer vector,
• generating a first abnormal wafer index of the first wafer based on a product of the first Euclidean distance and the first Cosine distance,
• generating a first characteristic variable by testing the fabricated first wafer, and
• generating a wafer defect prediction model through regression based on the first process variable, the second process variable, the first characteristic variable, and the first abnormal wafer index.