Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
2003-03-03
2004-05-04
Paladini, Albert W. (Department: 2125)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C700S100000, C700S121000, C073S865800
Reexamination Certificate
active
06732001
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a production management method for designating a processing order of product processing and dummy runs in a production operation requiring a dummy run for preventing contamination caused by the processing in the course of production.
2. Description of the Related Art
FIG. 20
is a flow chart illustrating processing in a conventional production management method. In
FIG. 20
, first, lots to be processed are arranged in order of priority (Step S
2001
). Then, the processing order of the lots to be processed and dummy runs is designated in accordance with the arranged order (Step S
2002
). Herein, the “dummy run” refers to an indirect operation performed so as to purify a state contaminated by the processing in each operation. Therefore, as the number of dummy runs is increased, an operation that is not directly related to a production operation also is increased, which prolongs the lead time of a lot and increases production costs.
A dummy wafer is used in a dummy run so as to manage a contaminated state in a processing chamber of a production apparatus as follows. First, a dummy wafer is inserted into a production apparatus in the same way as in an ordinary production wafer, and a dummy run is performed. After the dummy run is completed, the dummy wafer is taken out of the production apparatus, and the dummy wafer is measured for a contamination degree by using a measurement apparatus. In the case where the measurement result is determined as a contamination degree at which the subsequent production wafer (lot) can be processed, i.e., cleanness to some degree, the subsequent wafer (lot) is processed Alternatively, in the case where the measurement result is determined as a contamination degree at which the subsequent wafer (lot) cannot be processed, i.e., a contaminated state, a dummy run is performed again without processing the subsequent production wafer (lot). When the second and subsequent dummy runs are performed, the dummy wafer used in the first dummy run may be used, or a new dummy wafer may be used.
In the case where it is determined that contamination can be eliminated to such a desired degree as to satisfy a contamination degree of the subsequent production wafer by performing a dummy run, even when a dummy wafer is used, it is not required to measure a contamination degree of the dummy wafer after the dummy run. In this case, the dummy wafer is used for the purpose of adsorbing a contamination material and enhancing a contamination elimination effect of the dummy run. Therefore, in the case where there is no effect for eliminating the contamination in the dummy run, it is not required to use a dummy wafer.
FIG. 21
shows an example of a processing order of lots to be processed and dummy runs in a conventional production management method. Herein, WK
1
to WK
9
represent lots to be processed, and TP
1
to TP
9
represent processing times of the lots WK
1
to WK
9
, respectively. Furthermore, TD
3
represents processing time of a dummy run between WK
3
and WK
2
, between WK
6
and WK
5
, and between WK
9
and WK
8
. TD
2
represents processing time of a dummy run between WK
2
and WK
1
, between WK
5
and WK
4
, and between WK
8
and WK
7
.
In
FIG. 21
, it is assumed that the operation for processing WK
2
causes more contamination than that of WK
1
, and the operation for processing WK
3
causes more contamination than that of WK
2
. Furthermore, it is assumed that the operation for processing WK
5
causes more contamination than that of WK
4
, and the operation for processing WK
6
causes more contamination than that of WK
5
. Furthermore, the operation for processing WK
8
causes more contamination than that of WK
7
, and the operation for processing WK
9
causes more contamination than that of WK
8
.
According to the production management method, as shown in
FIG. 21
, first, the lots to be processed are arranged in order of priority: WK
3
, WK
2
, WK
1
, WK
6
, WK
5
, WK
4
, WK
9
, WK
8
, WK
7
(Step S
2001
).
Then, in the processing described below, the processing order of the lots to be processed and the dummy runs is designated in accordance with the arranged order (Step S
1402
).
Since the operation for processing WK
3
causes more contamination than that of WK
2
, and the operation for processing WK
2
causes more contamination than that of WK
1
, it is necessary to insert dummy runs between WK
3
and WK
2
and between WK
2
and WK
1
.
Next, since the operation for processing WK
6
causes more contamination than that of WK
5
, and the operation for processing WK
4
causes more contamination than that of WK
5
, it is necessary to insert dummy runs between WK
6
and WK
5
and between WK
5
and WK
4
.
Furthermore, since the operation for processing WK
9
causes more contamination than that of WK
8
, and the operation for processing WK
8
causes more contamination than that of WK
7
, it is necessary to insert dummy runs between WK
9
and WK
8
and between WK
8
and WK
7
.
Thus, as an entire processing order, lots and dummy runs are arranged as follows: WK
3
, dummy run, WK
2
, dummy run, WK
1
, WK
6
, dummy run, WK
5
, dummy run, WK
4
, WK
9
, dummy run, WK
8
, dummy run, and WK
7
.
However, according to the above-mentioned production management method, the lots to be processed are arranged merely in order of priority. The lots to be processed are not rearranged considering the contamination degree in each operation. Therefore, 6 dummy runs in total are designated between WK
3
and WK
2
, between WK
2
and WK
1
, between WK
6
and WK
5
, between WK
5
and WK
4
, between WK
9
and WK
8
, and between WK
8
and WK
7
, whereby the total processing time of the dummy runs becomes (total time=TD
3
+TD
2
+TD
3
+TD
2
+TD
3
+TD
2
). This increases the processing number and the processing time of the dummy runs. Consequently, the operating rate of equipment is decreased, and the lead time of a lot is prolonged. Furthermore, an increase in dummy wafer used for dummy runs causes production costs to increase.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is an object of the present invention to provide a production management method in which the processing order of lots is designated considering the contamination degree in each operation, whereby the processing number and the processing time of dummy runs can be reduced, the operating rate of equipment can be enhanced, and the lead time of a lot can be shortened, and furthermore, production costs can be reduced by decreasing dummy wafers used in the dummy runs.
In order to achieve the above-mentioned object, a production management method of the present invention includes: in production equipment for performing a plurality of production operations having different processing conditions in the same processing chamber, previously determining a contamination degree that is an index of how a product or the production equipment is contaminated in the production operations, and setting the contamination degree of the product or the production equipment after processing the product in the production operations and recording the contamination degree in one or a plurality of first storage apparatus; grouping a plurality of the products having the same contamination degree recorded in the first storage apparatus into one contamination group and recording the products in one or a plurality of second storage apparatus on the basis of the contamination group; and designating execution of processing in the production operations on the basis of the contamination group recorded in the second storage apparatus.
According to the above configuration, a dummy run only needs to be performed every time the processing of each contamination group is completed. Therefore, the number of dummy runs can be reduced as a whole, and the processing time of the dummy runs can be shortened substantially. This can enhance the operating rate of equipment and shorten the lead time of a lot. Furthermore, production cost
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