semi合集-English.pdf - 第92页

SEMI E10-0304 E © SEMI 1986, 2004 6 the equipment to a condition where it can perform its intended function is includ ed in facilities-related downtim e. 5.10 NON-SCHEDULED STATE — The time (non - scheduled t i me) whe n…

SEMI E10-0304

• Communications links with other equipment or

host computers.

5.8.6.1 Any downtime created by the items listed

above shall be included in facilities-related downtime.

For example, if, as a result of a scheduled 15-minute

power outage an otherwise unnecessary cryo pump

regeneration is needed, all time required to return the

equipment to a condition where it can perform its

intended function is included in facilities-related

downtime.

5.9 UNSCHEDULED DOWNTIME STATE — The

time (unscheduled downtime) when the equipment is

not in a condition to perform its intended function due

to unplanned downtime events:

• Maintenance delay (maint-delay)

• Repair

• Change of consumables/chemicals

• Out-of-spec input

• Facilities related (fac-rel)

5.9.1 Maintenance Delay — The time (maint-delay

downtime) during which the equipment cannot perform

its intended function because it is waiting for either user

or supplier personnel or parts (including

consumables/chemicals) associated with maintenance.

Maintenance delay may also be due to an administrative

decision to leave the equipment down and postpone

maintenance.

5.9.1.1 Maintenance delays may occur at any point in

the maintenance process. These maintenance delay

downtimes should be tracked separately from

maintenance time. Delay downtime is included in time

off-line, but not in maintenance time (see Sections 6.3

and 6.4 Equipment Availability and Maintainability).

5.9.2 Repair — The sum of the times (repair

downtimes) for:

• Diagnosis: The procedure of identifying the source

of an equipment problem or failure.

• Corrective action: The maintenance procedure

(including equipment ramp-down and ramp-up, re-

booting, resetting, recycling, restarting, reverting to

a previous software version, etc.) employed to

address an equipment failure and return the

equipment to a condition where it can perform its

intended function.

• Equipment test: The operation of equipment to

demonstrate equipment functionality (e.g., system

reaches base pressure, wafers transfer without

problem, gas flow is correct, plasma ignites, source

reaches specified power).

• Verification run: The processing and evaluation of

units after corrective action to establish that the

equipment is performing its intended function

within specifications.

5.9.3 Change of Consumables/Chemicals — The time

(change of consumables/chemicals downtime) for the

unscheduled interruption of operation to replenish the

raw materials of semiconductor processing. It includes

changes of gas bottles, acids, targets, sources, etc., and

any purging, cleaning, or flushing normally associated

with those changes. It does not include delays in

obtaining these consumables/chemicals.

5.9.4 Out-of-Spec Input — The time (out-of-spec input

downtime) when the equipment cannot perform its

intended function solely as a result of problems created

by out-of-specification or faulty inputs. Those inputs

include:

• Support tools (e.g., warped cassettes or wafer

carriers, faulty probe cards, reticles),

• Unit (e.g., upstream process problems, warped

wafers, contaminated wafers, warped lead frames),

• Test data (e.g., metrology tool out of calibration,

misread charts, erroneous data interpre-

tation/entry), and

• Consumables/chemicals (e.g., contaminated acid,

leaky target bond, degraded photo resist, degraded

mold compound).

5.9.4.1 Any downtime created by the items listed

above shall be included in out-of-specification input

downtime. For example, if, as a result of an

intermittent probe card short, a prober/tester system is

put down for repair, all downtime incurred prior to

identifying the problem is re-categorized as out-of-

specification input downtime.

5.9.5 Facilities Related — The time (facilities-related

downtime) when the equipment cannot perform its

intended function solely as a result of out-of-

specification facilities. Those facilities include:

• Environmental (e.g., temperature, humidity,

vibration, particle count),

• House hookups (e.g., power, cooling water, house

gases, exhaust, LN2), and

• Communications links with other equipment or

host computers.

5.9.5.1 Any downtime created by the items listed

above shall be included in facilities-related downtime.

For example, if, as a result of an unscheduled 15-

minute power outage, an otherwise unnecessary cryo

pump regeneration is needed, all time required to return

SEMI E10-0304

the equipment to a condition where it can perform its

intended function is included in facilities-related

downtime.

5.10 NON-SCHEDULED STATE — The time (non-

scheduled time) when the equipment is not scheduled to

be utilized in production, such as unworked shifts,

weekends, and holidays (including shutdown and start-

up).

5.10.1 If equipment is out of the production plan due to

off-line training or an installation, modification,

rebuild, or upgrade (hardware or software) that cannot

be accommodated by the regular preventive

maintenance schedule, its status is the non-scheduled

state. This includes any qualification time required to

bring the equipment to a condition where it can perform

its intended function from one of these states.

5.10.2 Any maintenance done to equipment during

these periods cannot be counted in the non-scheduled

state, since all maintenance must fall into either

scheduled or unscheduled downtime (this includes

automatic maintenance routines such as a programmed

cryo pump regeneration).

5.10.3 By the same convention, any production or

engineering work done during these periods must fall

into either productive or engineering time (this includes

an unattended operation that may shut itself off “after

hours”).

6 RAM Measurement

6.1 Reliability, availability, and maintainability are

measures of equipment performance which have been

used widely in industry for decades. This section

defines them for the semiconductor industry in a

manner that is consistent with existing industrial

standards. Along with the definitions for RAM are

given indicators by which these measures can be

quantified.

6.2 EQUIPMENT RELIABILITY — The probability

that the equipment will perform its intended function,

within stated conditions, for a specified period of time.

NOTE 4: Two different methods of measuring this are

presented, productive time (Sections 6.2.1 and 6.2.2) and

equipment cycles (Sections 6.2.3 and 6.2.4):

• Productive time only considers what happens while

making units (useful for manufacturing operation

purposes).

• Equipment cycles take into account the wear and tear

created by every machine cycle during all equipment

states (useful for equipment reliability purposes).

6.2.1 MTBF

— Mean (productive) time between

failures; the average time the equipment performed its

intended function between failures; productive time

divided by the number of failures during that time.

Only productive time is included in this calculation.

Failures that occur when an attempt is made to change

from any state to a productive state are included in this

calculation. Using MTBF

, therefore, requires that the

user not only have the capability of capturing failure

information, but also tracking and categorizing total

time accurately.

time productive during occur that failures of #

time productive

MTBF

6.2.2 E-MTBF

— Mean (productive) time between

equipment-related failures; the average time the

equipment performed its intended function between

these equipment-related failures; productive time

divided by the number of equipment-related failures

during that time. Only productive time is included in

this calculation. Equipment-related failures that occur

when an attempt is made to change from any state to a

productive state are included in this calculation. Using

E-MTBF

, therefore, requires that the user not only

have the capability of capturing failure information, but

also tracking and categorizing total time and the root

causes of failures accurately.

productive time

# of equipment-related failures that

occur during productive time

–MTB

6.2.3 MCBF — Mean cycles between failures; the

average number of equipment cycles between failures;

total equipment cycles divided by the number of

failures during those cycles. This calculation

transcends equipment states to include all cycles that

the system, or subsystem, being considered

experiences. It does not require tracking equipment

states, only equipment cycles and equipment failures.

failures of #

cycles equipment total

MCBF =

6.2.4 E-MCBF — Mean cycles between equipment-

related failures; the average number of equipment

cycles between these equipment-related failures; total

equipment cycles divided by the number of equipment-

related failures during those cycles. This calculation

transcends equipment states to include all cycles that

the system, or subsystem, being considered

experiences. It does not require tracking equipment

states, only equipment cycles and equipment-related

failures and their root causes.

total equipment cycles

# of equipment-related failures

–MCB

SEMI E10-0304

• Unworked shifts, days

•

Installation, modification

rebuild or upgrade

•

Off-line training

• Shutdown/Start-up

Non-Scheduled

Time

Total Time

Operations

Time

Uptime

•

Process experiments

• Equipment experiments

•

Software qualification

Engineering

Time

Manufacturing

Time

Productive

Time

• Regular production

• Work for 3rd party

•

Rework

• Engineering runs

Standby

Time

•

No operator

• No product

• No support tool

Downtime

•

Maintenance delay

•

Repair

•

Change of

consumables/chemicals

•

Out-of-spec input

•

Facilities related

Unscheduled

Downtime

Scheduled

Downtime

•

Maintenance delay

• Production test

• Preventive maintenance

•

Change of

consumables/chemicals

•

Setup

•

Facilities related

Figure 2

SEMI E10 Summary of Time

6.3 EQUIPMENT AVAILABILITY — The probability that the equipment will be in a condition to perform its

intended function when required.

6.3.1 Equipment Dependent Uptime — The percent of time the equipment is in a condition to perform its intended

function during the period of operations time minus the sum of all maintenance delay downtime, out-of-spec input

downtime, and facilities-related downtime. This calculation is intended to reflect equipment reliability and

maintainability based solely on equipment merit.

equipment dependent uptime (%) =

equipment uptime × 100

(oper-time – (all maint-delay DT + out-of-spec input DT + fac-rel DT))

6.3.2 Supplier Dependent Uptime — The percent of time the equipment is in a condition to perform its intended

function during the period of operations time minus the sum of user maintenance delay downtime, out-of-spec input

downtime, and facilities-related downtime. This calculation subtracts only user maintenance delay downtime from

the period, thereby taking into account supplier delays for parts and service. The intention is to provide an effective

performance measurement for use in supplier service contracts.

supplier dependent uptime (%) =

equipment uptime × 100

(oper-time – (user maint-delay DT + out-of-spec input DT + fac-rel DT))

6.3.3 Operational Uptime — The percent of time the equipment is in a condition to perform its intended function

during the period of operations time. This calculation is intended to reflect overall operational performance for a

piece of equipment.

operational uptime

(%)

equipment uptime

100

operations time