Dispatch control method for furnace process
A dispatch control method for a furnace process including the following steps is provided. Before a plurality of lots of wafers is loaded into a furnace, the characteristic variation value of each of the plurality of lots of wafers is calculated. The plurality of lots of wafers is ordered according to the size of the characteristic variation values. The plurality of lots of wafers is placed in the furnace in a descending order of the characteristic variation values corresponding to a plurality of locations in the furnace causing the characteristic variation values to change from smaller to larger.
1. A dispatch control method for a furnace process, comprising:
calculating a characteristic variation value of each of a plurality of lots of wafers before the plurality of lots of wafers is loaded into a furnace;
ordering the plurality of lots of wafers according to a size of the characteristic variation values; and
placing the plurality of lots of wafers in the furnace in a descending order of the characteristic variation values corresponding to a plurality of locations in the furnace causing the characteristic variation values to change from smaller to larger.
2. The method of claim 1 , further comprising defining a characteristic parameter value related to a product before the plurality of lots of wafers is loaded into the furnace.
3. The method of claim 2 , wherein the characteristic parameter value comprises a threshold voltage, a saturation current, or a resistance value.
4. The method of claim 1 , wherein the characteristic variation values are calculated from a function of the characteristic variation values, and the function of the characteristic variation values is related to at least one of a gate length and a thickness of a residual silicon oxide used for forming a source and a drain.
5. The method of claim 1 , further comprising performing a selection on the ordered plurality of lots of wafers.
6. The method of claim 5 , wherein a method of performing the selection on the plurality of lots of wafers comprises performing the selection on the ordered plurality of lots of wafers according to an average lot size interval.
7. The method of claim 5 , wherein a method of performing the selection on the plurality of lots of wafers comprises providing a lot number to each of the ordered plurality of lots of wafers in order, and selecting the lot number by rounding a value calculated according to the following formula:
Lot
number
=
1
+
[
(
Total
lot
size
of
a
pluraqlity
of
lots
of
wafers
-
1
)
×
N
Maximum
lot
size
of
a
batch
-
1
]
wherein N is an integer of at least 0, and a maximum value of N is one less than a maximum lot size of a batch.
8. The method of claim 1 , wherein the characteristic variation values of the plurality of lots of wafers are calculated via an advanced process control system.
9. The method of claim 1 , wherein a placement location of each of the plurality of lots of wafers in a batch in the furnace is decided via a dispatch system.
10. The method of claim 1 , wherein a dispatch of the plurality of lots of wafers is executed via a manufacturing execution system.