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Revision
Date
Initiator
Reviewer Signature
Approver’s Signature
1
23 Jun 2015
Lavendra
Sunanda Babu
Prabhakar Rao
2
17 Jul 2015
Lavendra
Sunanda Babu
Prabhakar Rao
3
24 Nov 2015
Lavendra
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1. Purpose
This document describes the steps to be followed by the user, to etch the
required film/features on his /her sample.
2. Scope
It covers the instructions for operation the system, the safety precautions to
be followed while operating the system and the penalty, in case of any
deviations from following SOP.
3. Pre-Checks
 Make sure you reserve the tool through FOM and Log on to FOM before
using the tool.
 The tool software should be logged in when you arrive at the tool. If,
however, it is logged out, follow these steps:
 Click Log In at the top left corner of the screen.
 Select Process Engineer.
 Type the password sts and click Login.
 Clean the backside of your wafer, verify that it is CLEAN & SMOOTH Never put resist that has not been fully cured into this tool.
 For etches deeper than 400μm, or if the remaining wafer thickness will
be less than 100μm, a carrier wafer is required.
 Wafers/pieces smaller than 4” must be mounted to the carrier wafer.
o The SPTS Pegasus runs very powerful processes that generate a
large amount of heat. Thus it is extremely important that wafers
have adequate cooling to prevent damage to your sample. The
tool employs a thermally controlled electrostatic chuck with
backside helium pressure to provide temperature control of your
wafer. However, poorly cleaned or warped wafers will drastically
increase the thermal resistance between your wafer and the
chuck and can cause your wafer to overheat. It is imperative that
you clean the back of your wafer immediately before loading
into the tool (even a “clean” wafer that has been carried around
in a box will slowly collect particles). IPA and wipes are provided at
the Wafer Mounting Station to clean your wafer. Below are some
examples of wafers that will not pass leak check and must be
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cleaned thoroughly. Essentially if a particle is large enough that
you can see it without assistance then it is large enough to
increase the helium leak rate.
 Before your run TDESC clean of 3 min is must.
 With a dummy carrier run the recipe which you are going to run on your
actual samples for 5 min.
4. Operating Instructions
4.1 Sample Loading
 Once your wafers are clean, they are ready to be loaded into the tool
 From the MANUAL screen, press VENT button to release the loadlock
vacuum.
 Before loading make sure you double check and clean the back side of
your wafer.
 Place you wafers in the carousel with the flat towards the center of the
carousel.
 Line the flat up with the lines in the slot.
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 Close the lid press the MAP button and then PUMP to evacuate the
loadlock.
 Stay in transport screen.
 Once the loadlock reached base pressure the buttons on the right side of
the screen highlights.
 Select from and to by left clicking the LOADLOCK and CHAMBER (as start
and destination points)
 Press START to transfer the substrate
4.2 Sample Processing
 Go to recipe screen expand the PEG1 tree by clicking +, then expand
PROCESS MODULE.
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 You can select your required recipe and expand it to change only the
time if it is Standard recipe.
 Select the Apply button to save the changes.
 Go to MANUAL screen and then to PROCESS screen, select processing on
the right side of the screen.
 You can find the recipe you are going to run by clicking previous or next
on the bottom.
 Select the recipe and press START on the top.
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 When the process started, check Backside Gas Leak.
 Typical range is 40-80 mT/min. If greater than 150 mT/min, the tool will
alarm.
 If there is an alarm and you wish to continue, go to the Alarms page,
clear the alarm and click Retry, otherwise Abort.
 If the alarm is over 240 mT/min, DO NOT click anything! Contact the tool
engineer to retrieve your wafer.
4.3 Sample Unloading
 Once the process finished the chamber indicates GREEN,
 Go to TRANSPORT screen select FROM and TO by left clicking on
CHAMBER and LOAD lock (as start and destination points)
 Press START to transfer the substrate out.




Press VENT to release vacuum.
Open the lid and take off the sample.
Close the lid and Press PUMP to leave the loadlock in vacuum.
Please measure the Etch Depth and update in log book in results column.
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5. Precautions
a. Clean the backside of the wafer with IPA (Using only lint free wipe) before loading.
b. Make sure you select your required recipe only and edit only time of the recipe.
c. Fill the log mentioning backside leak and ALARAMS.
6. Contact Point
If you feel any difficulty while operating or any issue with the tool.
Please contact the tool owners
Lavendra : 8088312524
Adithi : 9845444306
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Frequently raised issues:
1. Load lock pumping
- If the load lock isn’t pumping as usual, try to press gently on the lid
and you can hear the change in pumping sound.
2. Alarms:
a. Back side helium leak high (>125mT) – RED alert
– Back side leak goes high only when the back side of the wafer is not properly
cleaned. Get back the wafer to load lock, clean the back side of the wafer with
new lint free wipe and IPA. After running 3 min of TDESC clean recipe without
wafer continue your process. If the problem unresolved please contact the
process engineer immediately.
b. Temperature stabilization not happen in the given time – RED alert
– This alarm will rise when the running recipe temperature is different with
previous temperature. Clear the alarm and retry, the stabilization restarts and
jumps when it reaches the required temperature.
c. C4F8 gas not stabilized – RED alert
– Call BMS (115), ask to charge the C4F8 gas line. Once you get the confirmation
of charged line from BMS, clear the alarm and click retry to resume the process.
Caution: do not click retry before confirmation, so your process get aborted or
disturbed.
If raised issue is other than above stated, Please contact the DRIE process engineer.
NOTE: Any deviations from this SOP will be
considered as a breach of User Agreement conditions
and will result in appropriate disciplinary action. For
additional details please refer to detailed manual on
the nnfc twiki (route to the manual is as follows nnfc
twiki> Main web> Cleanroom> Equipments> Dry
Etch> DRIE (STS)> Documents>user manuals.
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