semi合集-English.pdf - 第961页
SEMI E124-1103 © SEMI 2003 16 ( ) ( ) ( ) () () 0.9524 0.9400 90.48% yield line test efficienc y yie ld yield =× ≈× ≈ (19) ( ) ( ) ( ) () ( ) 0.4341 0.9048 39.27% overall factory volume yield efficienc y e fficiency effi…
SEMI E124-1103 © SEMI 2003 15
(
)
-
-
-
2355.5 minutes
2592.0 minutes
90.88%
best case cycle time
throughput rate and
cycle time efficiency
average cycle time
=
≈
≈
(8)
(
)
(
)
(
)
()
wafers
812.4 minutes 0.2182
minute
177.3 wafers
critical theoretical bottleneck
WIP cycle time throughput rate
=×
≈×
≈
(9)
()
[][][][]
maximum
average
number of
number
units processed
of tools
simultaneously
in
on a tool of
equipment
equipment
type
type
275 225 11 125 waf
process
capacity
eE
e
e
=×
∈
= × + × +×+×
∑
ers
150 50 1 25 wafers
226 wafers
=+++
=
(10)
()
(
)
(
)
{
}
()( )
{}
{}
{}
min ,
max ,
min 513.9, 177.3 wafers
max 513.9, 177.3 wafers
177.3 wafers
513.9 wafers
34.49%
critical average
WIP WIP
WIP
efficiency
critical average
WIP WIP
=
≈
≈
≈
(11)
() ()
()()
-
-
0.9087 0.3449
31.34%
throughput rate
production WIP
and cycle time
efficiency efficiency
efficiency
=×
≈×
≈
(12)
(
)
()()
()()
{}
{}
[]
2
2
2
2
1
1
log
min ,
1
513.9 177.3 1 wafers
log
min 513.9, 177.3 wafers
1
690.2 wafers
log
177.3 wafers
1
log 3.894
1
1.961
normalizing
exponent
average critical
WIP WIP
average critical
WIP WIP
=
+−
≈
+−
≈
≈
≈
≈ 0.5099
(13)
()
()
()
0.5099
0.3134
55.35%
normalizing
exponent
normalized
production
production
efficiency
efficiency
=
≈
≈
(14)
(
)
177.3 wafers
226 wafers
78.43%
critical WIP
balance
efficiency
process capacity
=
≈
≈
(15)
() ()
()()
0.5535 0.7843
43.41%
normalized
volume balance
production
efficiency efficiency
efficiency
=×
≈×
≈
(16)
(
)
891,642.1 wafers
938,571.0 wafers
95.00%
g
ood unit equivalents out
test
yield
finished units out
=
≈
≈
(17)
(
)
()( )
()()
938,571 wafers
938,571 wafers 46,929 wafers
938,571 wafers
985,500 wafers
95.24%
finished units out
line
yield
finished units out scrapped units out
=
+
=
+
=
≈
(18)
SEMI E124-1103 © SEMI 2003 16
(
)
(
)
(
)
()()
0.9524 0.9400
90.48%
yield line test
efficiency yield yield
=×
≈×
≈
(19)
(
)
(
)
(
)
()()
0.4341 0.9048
39.27%
overall factory volume yield
efficiency efficiency efficiency
=×
≈×
≈
(20)
SEMI E124-1103 © SEMI 2003 17
RELATED INFORMATION 3
SUPPLEMENTARY INFORMATION
NOTICE: This related information is not an official part of SEMI E124 and was derived from work by the task
force. This related information was approved by full letter ballot procedures on April 11, 2003.
R3-1
R3-1.1 As was mentioned in Section 2.1, there are at
least three things in need of measurement in a factory:
production, utilization of assets, and costs. This guide
focuses on evaluating production; utilization of assets
and costs (as well as other economic factors) are
outside its scope. For measuring effectiveness of asset
use, an average (over all of the equipment in the
factory) of overall equipment efficiency (OEE)
weighted by cost of ownership (COO) can be defined in
one of those documents. However, the use of
consumables, utilities, and human resources would still
need to be comprehended. For measuring costs, some
other new standard might define a new metric (like
COO) for the cost of factory ownership in such terms as
$/(good wafers), $/(good chips), $/(metal levels),
$/(good transistors), $/circuit, or $/bit.
R3-1.2 As was mentioned in Section 3.2, the metrics in
this guide are intended for evaluating the overall health
of the factory production, not for diagnosing problems
(or opportunities for improvement) in the factory,
although some component metrics can be used that
way. These metrics should indicate whether the factory
is running poorly (like taking a person’s temperature
tells whether they are sick) while some of its
components and other diagnostic metrics might indicate
what the cause of the problem is (like doing a blood
analysis in the lab identifies the disease). The
following are examples of metrics not in this guide that
can be used for diagnosis:
• ratio of turns to work in process (WIP) at key
operations or for blocks of operations.
• overall WIP distribution.
• daily starts and output.
• defect density.
• throughput, utilization, and available up-time of
bottleneck equipment.
NOTICE: SEMI makes no warranties or
representations as to the suitability of the standard set
forth herein for any particular application. The
determination of the suitability of the standard is solely
the responsibility of the user. Users are cautioned to
refer to manufacturer’s instructions, product labels,
product data sheets, and other relevant literature
respecting any materials mentioned herein. These
standards are subject to change without notice.
The user’s attention is called to the possibility that
compliance with this standard may require use of copy-
righted material or of an invention covered by patent
rights. By publication of this standard, SEMI takes no
position respecting the validity of any patent rights or
copyrights asserted in connection with any item
mentioned in this standard. Users of this standard are
expressly advised that determination of any such patent
rights or copyrights, and the risk of infringement of
such rights, are entirely their own responsibility.
Copyright by SEMI® (Semiconductor Equipment and Materials
International), 3081 Zanker Road, San Jose, CA 95134. Reproduction o
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consent of SEMI.