Tystar 10
MOS Clean Polycrystalline
Silicon LPCVD Furnace
(4” and 6”)
(tystar10)
1.0
Title
Tystar10 MOS Clean Polycrystalline
Silicon LPCVD Furnace (4” and 6”) (tystar10)
2.0 Purpose
Tystar10 is our new 6” LPCVD polysilicon deposition
tube, which is maintained for MOS-clean, doped and undoped polysilicon
processes. This tube is capable of
processing both 4” and 6” wafers.
3.0 Scope
This
document has specific information about Tystar10, our 6” doped and undoped
LPCVD Polysilicon deposition tube. This tube is maintained for MOS-clean
processes of thickness < 0.7 micron. Please refer to Chapter 5.0 of
the lab manual for general information on LPCVD furnaces.
4.0 Applicable Documents
Chapter 5.0 of
lab manual (Tylan LPCVD furnaces)
5.0 Definitions
& Process Terminology
5.1
MOS tube: Tystar10 is a MOS clean tube dedicated to IC type of
fabrication.
5.2
Silane (SiH4): A gas used in our polysilicon (doped and undoped)
processes.
5.3
Phosphine (PH3): A gas used to doped the polysilicon film. Microlab
uses 50% PH3 and 50% SiH4
mixture for safety purpose.
5.4
ROP: Remote-Operation Panel
5.5
ALMACK : Alarm Acknowledge
is a button used to proceed to next step in recipe
5.6
ABORT: This key can be used to abort the process. This is
commonly used for unloading the wafers, where users invoke the recipe again,
after run has been completed and properly vented. The tube will open for the
users to unload their wafers followed by abort to load the standby recipe, and
before leaving the area.
Machine interlock messages
5.7
ANTLK: Above
atmosphere interlock, no process gas can flow (including N2).
5.8
NTLK: Below
process pressure (2 Torr) interlock, no process gas can flow.
5.9
DNTLK: Door interlock,
door is not closed; no process gas can flow.
5.10
GNTLK: Gate valve
interlock, gate valve is not open, no process gas can flow.
5.11
VNTLK: Vacuum
interlock, pump problem, no process gas can flow.
6.0
Safety
Follow
general safety guidelines in the lab as well as the specific safety rules as
per follows:
6.1
Tytar10 utilizes potentially hazardous gases and high
electric power (high amperages to heat its elements). Do not open the front or the back panels, as it can expose you to
high power circuitry.
6.2
Special care must be taken when the tube is aborted and
while in deposition step. The toxic process gases present will need to be
properly vented. In an emergency situation (earthquake, fire) the process can
be aborted. Make sure toxic gases are properly vented by a series of pump and
purges and by running the “10purge” recipe. Ask process staff if you need help
or if you have any questions in this regard. Do not alter any of the standard
processes and specially do no skip any important purge or vent step in your
recipes.
6.3
All new recipes have to be checked by process staff, before
they can be used on any of our Tylan or Tystar furnaces.
6.4
This tube is a dedicated polysilicon tube, and process
temperatures are in the typically around 615ºC. Do not run the tube at
temperatures above 650ºC, as it may crack the tube, which has thick polysilicon
deposited on its walls, and under stress.
7.0
Statistical/Process Data
Pertinent information can
be found on the following sites:
7.1
Process monitoring test
section of the Microlab’s home page.
7.2
Problem and comments
section under equipment section of the wand.
7.3
Enable message for Tystar10.
8.0
Available
Processes &Gases
Tystar10 tube is assigned
to standard doped and undoped polysilicon processing.
8.1
Standard undoped
Polysilicon process: The standard undoped polysilicon “10suplya” recipe uses
Silane gas to deposit, undoped film (PH3 = 0), at process pressure
and temperature of 375 mTorr and 615ºC, respectively.
8.2
Standard doped
Polysilicon process: The standard doped polysilicon “10sdplya” recipe, uses
Silane (SiH4) and fixed amount of Phosphine (PH3) to
deposit, doped polysilicon film at process pressure and temperature of 375
mTorr and 615ºC, respectively.
8.3
Variable doped
Polysilicon process: The variable doped polysilicon “10vdplya” recipe, allows
for the user to vary the amount of Silane (SiH4), Phosphine (PH3) and process
pressure, below the maximum specified
amount in the recipe. Doped polysilicon film is deposited at fixed process
temperature of 615ºC.
8.4
This tube is calibrated
in the temperature range of 500 – 650ºC. Do not attempt to run any processes
outside of this temperature range, especially process temperatures above 650ºC are not allowed. This could crack
the tube.
8.5
Available gases on this
tube are SiH4, PH3, N2 and N2 VAC
(for pressure control).
9.0
Furnace Operation
9.1
Control
Key description
Many of the operational commands can be executed
from ROP. Function keys such as “Recipe”, “Run”, “Hold”, “Clock”, “Status” and
more are also available. Figures & Schematics at the
end of this chapter displays all these function keys. There are two ALMACK keys
available on the ROP. The one on the far right side just above the ABORT key is
the main one to use.
9.2
Operational
Procedure/Guidelines
Recipes can be loaded from “TYSTAR10 recipe”
diskette and Tycom terminal. Run your process. Take your wafers out, after your
process is completed. Note, you will need to wait for the boat to completely go
back in, before you can load the standby recipe. This means, once you find your
run completed, ALMACK twice out of the “flush & hold” step, then run the
recipe again, get your wafers out (This takes about 12 minutes). Then, ALMACK
through the unload step to send the boat in and make sure the door is
completely closed, before you ABORT the process. Finally, load the standby
recipe. Please note, aborting the tube before the boat-loading step is
completed, stops the boat loader in its track with the door open.
9.2.1
Recipes
Tystar10 recipes are residing on a dedicated diskette marked as “Tystar10 recipes”. These recipes have a standard format with three pump and purge cycles before and after the deposition step. This is designed to better control the film particles by keeping the tube cleaner. There are standard doped & undoped polysilicon recipes available on Tystar10 disk, as well as standby, vent and purge recipes. The vent and purge recipes are designed to speed up recovery process.
See the Appendix
for more details on the available recipes.
|
10suplya
recipe: Standard undoped
polysilicon process (PH3 =
0). 10sdplya
recipe: Standard doped polysilicon
process. 10vdplya
recipe: Variable doped polysilicon
recipe (var.SiH4,PH3, press.) 10stnbya
recipe: Standby recipe to be used, post polysilicon
deposition. 10purge
recipe: Additional recipe available to
purge and vent the tube.* 10vent
recipe: Additional recipe available
to vent the tube.* |
Note (*): The vent and purge recipes can be used for
quick vent or pump/purge cycles. The abort as you know, takes the recipe back
to its first step. This may take a long time for the tube to vent. This is
because the initial step bleeds only about one liter of nitrogen into the tube,
in which case it takes a long time to bring the tube to atmosphere. This can be
accomplished much faster by loading one of the two recipes noted above, however
take extreme care and make sure that you do not use the vent recipe when
harmful gases are present (abort at deposition step), load the purge recipe
instead. This can come handy when the abort has occurred, while still in
deposition step or if the origin of the abort sequence is not known (did it
abort at deposition step?).
9.2.2
Recipe
Modification and New Recipe Generation
As always, modification to standard recipes is not allowed. There is 10vdplya recipe available on the TYSTAR10 diskette for users to vary the process parameters. Talk to process staff if you need to develop other recipes.
9.2.3
Recipe Loading
Type LO followed by recipe name and 10 to load the recipe onto the tube from Tycom terminal. e.g. “LO 10suplya 10”.
9.2.4
Running Recipe
Once the recipe is loaded you can type RU followed by tube number (10) or simply press run button on the ROP terminal.
9.2.5
Wafer Loading
Once the boat is out, replace dummy wafers with your work wafers. There is a 20 minutes window available for this task. Once the 20 minutes elapses, the boat loader will automatically go in. Do not worry, simply ALMACK through to cycle back to “ boat unload” step and wait for the boat to come out. You have another 20 minutes to load your wafers.
9.2.6
Unloading Wafers
Once the process is completed the furnace will wait in flush and hold step. You will need to ALMACK twice out of this step to vent the tube. You will need to run the recipe again so that the boat loader will bring the tube out. You will then need to ALMACK to send the boat in and wait for the door to completely close. You can then abort the process and load the standby recipe, before signing off.
9.2.7
Standby Recipe
(finishing up)
Once your run is completed and your work wafers are out, you will need to load & run the standby recipe, 10stnbya. Doped poly silicon runs will need to be annealed as per follows.
9.2.8 Doped Polysilicon Films need to be annealed to uniformly diapers the dopant in the deposited film. This can be accomplished by annealing the wafers in Tylan7 furnace. The typical recipe for this is HIN2ANNL for 30 minutes at 950ºC.
10.0 Troubleshooting Guidelines
10.1
Failed Leak
Check
10.1.1
Check the machine status
screen on the Tycom terminal (type in “DI ST
10”).
10.1.1.1
If “GNTLK “ or
“VNTLK” is ON, stop and report
it as fault.
10.1.1.2
If “DNTLK” is ON, vent the tube. Run the
process again. Try this a couple of times, if necessary. Report as fault, if still
fails. There may be door sensor
problems.
10.1.1.3
If no interlock is ON,
vent the tube wipe the door and the o-ring. Run the process again, and if it
still fails, report it as a fault.
10.2
No Process Gas
Flow
10.2.1
Check the machine
status screen on the Tycom terminal (type in “DI ST 10”).
10.2.1.1
If any interlock is ON,
report it as fault.
10.2.1.2
Check the appropriate gas cylinder, if empty
report as fault.
11.0
Figures
& Schematics
12.0
Appendix
Recipes
|
|
10suplya |
|
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|
10sdplya |
|
|
Step ----- 01 05 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 |
Description ------------------------------- Initialize & system check Unload alarm Unload Boat Load on almack Load alarm Load boat Check door closed Pump1 Purge1 Pump2 Purge2 Pump3 Leak check Set temp Set K constant Temp stabilize Temp check Pump4 SiH4 flow (100 sccm) Pressure set (375 mTorr) Deposition step (Time Var.) Pump1 Purge1 Pump2 Purge2 Pump3 Purge3 Flush and hold Branch to backfill Loop back to flush & hold Backfill-1 Backfill-2 End |
Time -------- N/A 3 sec 10 min 20 min 3 sec 10 min 2 min 5 min 2 min 2 min 2 min 2 min 1 min 20 min 1 min 5 min 5 min 2 min 1 min 1 min Variable 2 min 2 min 2 min 2 min 2 min 2 min 1 hr 5 sec 1 sec 5 min 7 min |
|
Step ----- 01 05 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 |
Description ---------------------------- Initialize & system check Unload alarm Unload Boat Load on almack Load alarm Load boat Check door closed Pump1 Purge1 Pump2 Purge2 Pump3 Leak check Set temp Set K constant Temp stabilize Temp check Pump4 SiH4 & PH3 (100&4 sccm) Pressure set (375 mTorr) Deposition step(Time Var.) Pump1 Purge1 Pump2 Purge2 Pump3 Purge3 Flush and hold Branch to backfill Loop back to flush & hold Backfill-1 Backfill-2 End |
Time -------- N/A 3 sec 10 min 20 min 3 sec 10 min 2 min 5 min 2 min 2 min 2 min 2 min 1 min 20 min 1 min 5 min 5 min 2 min 1 min 1 min Variable 2 min 2 min 2 min 2 min 2 min 2 min 1 hr 5 sec 1 sec 5 min 7 min |
|
10vdplya |
|
10stnbya |
||||
|
Step ----- 01 05 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 |
Description ---------------------------- Initialize & system check Unload alarm Unload Boat Load on almack Load alarm Load boat Check door closed Pump1 Purge1 Pump2 Purge2 Pump3 Leak check Set temp Set K constant Temp stabilize Temp check Pump4 SiH4 & PH3 (variable gases allowed) Pressure set (max=flow+300 mTorr) Deposition step(Time Var.) Pump1 Purge1 Pump2 Purge2 Pump3 Purge3 Flush and hold Branch to backfill Loop back to flush & hold Backfill-1 Backfill-2 End |
Time -------- N/A 3 sec 10 min 20 min 3 sec 10 min 2 min 5 min 2 min 2 min 2 min 2 min 1 min 20 min 1 min 5 min 5 min 2 min 1 min 1 min Variable 2 min 2 min 2 min 2 min 2 min 2 min 1 hr 5 sec 1 sec 5 min 7 min |
|
Step ----- 01 05 10 15 20 25 30 35 40 45 50 55 60 |
Description ------------------- Initialize Load Check door closed Short pump Degas pump Hard pump Leak check Standby Branch to soft vent Loop back to standby Backfill-1 Backfill-2 End |
Time -------- N/A 10 min 2 min 2 min 10 min 2 min 1 min 1 hr 5 sec 1 sec 5 min 7 min |
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Rev. 00 – 4/01, S. Parsa
Rev. 01 – 8/06, J. Chang –
Minor revision of Section 5.0.