A method for analyzing in-line QCtest parameters is used to analyze a plurality
of lots of products, each lot of products having a lot number and being formed
using a plurality of equipments. At least one wafer of each lot of products is
tested by at least one in-line QC test item to generate an in-line QC test parameter.
The in-line QC test item, a sample test item and a wafer test item related to the
in-line QC test item are stored in a database. The database further stores the
in-line QC test parameter and data of a plurality of lots of high-yield product
stocks, such as various test items and test parameters. The method includes the
following steps: analyzing the in-line QC test parameter to determine whether the
in-line QC test parameter corresponds to a predetermined spec or not; searching
the database to find out the sample test item or the wafer test item related to
the in-line QC test item when the in-line QC test parameter does not correspond
to the predetermined spec; searching the database to find out the corresponding
test parameters of the high-yield product stocks according to the in-line QC test
item and the searched sample test item or the wafer test item; and generating a
correlation to illustrate the relationship between the in-line QC test item and
the sample test item, or the relationship between the in-line QC test item and
the wafer test item according to the searched high-yield product stocks.