Chapter 5 - TYLAN5 MOS Clean Gate/Dry ... - Berkeley Microlab

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1.0 Title
TYLAN5
MOS Clean Gate/Dry Oxidation and Annealing
Atmospheric Furnace (4” Only)
(tylan5)
TYLAN5 MOS Clean Gate/Dry Oxidation and Annealing Atmospheric Furnace (4” Only)
2.0 Purpose
TYLAN5 is an atmospheric furnaces that is designed for Gate oxidation, Dry oxidation and Nitrogen
Annealing. The furnace accommodates wafers up to 4” in diameter.
3.0 Scope
This chapter covers the general furnace description of TYLAN5, TYCOM Terminal and operation
procedures which include process recipe loading, wafer loading/unloading, user level problem
diagnosis, and wafer cleaning requirements.
4.0 Applicable Documents
Revision History
4.1 TYTAN Diffusion Furnace System Instruction Manual (copy in Office).
4.2 TYCOM 9900 Microprocessor Control System Instruction Manual (copy in Office)
4.3 Oxide Growth Chart, Semiconductor Technology Handbook (in the binder stored under TYCOM
terminal)
4.4 Material Safety Data Sheets for TCA (1,1,1-Trichloroethene), Oxygen, Nitrogen, and Forming
Gas H2/N2 (copy in Lobby).
5.0 Definitions & Process Terminology
5.1 MOS Furnace: This kind of furnaces is used to fabricate MOS devices (IC), whose performance
can be greatly impacted by trace contaminants. Wafers processed in a MOS furnace should
absolutely be MOS compatible (IC device). Absolutely no metal film in any MOS Furnace, except
the MOS sintering furnace, which allows only Al film.
5.2 Non-MOS Furnace: The wafers processed in this kind of furnaces may contain materials that are
not compatible with the MOS processes. If CMOS devices are processed in a Non-MOS furnace,
the electric performance of the devices may be changed. Wafers with metal films can be
processed in Non-MOS furnaces only with Microlab managerial permission.
5.3 Dry/Wet Oxidation: A high temperature process that oxidizes the underlying silicon to form
silicon oxide. Dry oxidation uses oxygen for better process control. Wet oxidation uses both DI
water and oxygen for fast reaction rate.
5.4 Gate Oxidation: A special dry oxidation process that produces high quality oxide with precise
thickness control.

tylan5 Chapter 5.5
5.5 Annealing: A high temperature process that uses nitrogen to keep wafers in an inert
atmosphere. Major applications include dopant diffusion and activation, LTO/PSG densification,
film stress release, and etc.
5.6 TCA Cleaning: A high temperature process that uses TCA and oxygen to clean the furnace
quartz parts and interior, by removing possible metallic contaminants in these areas.
6.0 Safety
Follow general safety guidelines in the lab as well as the specific safety rules as per follow:
6.1 Electric Shock Hazard: TYLAN furnaces utilize high electric power (high amperages) to
generate heat. Do not open the side panels or touch the high power electrical parts in the
furnace cabinet.
6.2 Chemical Hazard: TCA (1,1,1-Trichloroethene) is used for in-situ cleaning of quartz wares. It
poses moderate health and high fire hazard. Please refer to the MSDS for first aid information.
6.3 Burn Hazard. Cantilevers, boats, and wafers coming out of the furnace are very hot. Wear face
shield when loading/unloading wafers. Proceed with caution. Avoid touching of any furnace
quartz ware to prevent burning of your hands and contamination of the furnace. No flammable
chemical, especially organic solvents, in the load station when the tube is open.
6.4 All new recipes must be checked by the process staff, before they can be used on any TYLAN
furnaces. Customized recipes should be stored on the user’s diskette, not the standard diskettes.
7.0 Statistical/Process Data
7.1 Problem and comment section under equipment section of the wand.
7.2 Enable message for individual TYLAN furnace.
8.0 Available Process, Gases, Process Notes
Available Processes
8.1 Gate Oxidation.
8.2 Dry Oxidation (maximum temperature 1050ºC).
8.3 Nitrogen annealing (maximum temperature 1050ºC).
8.4 TCA clean.
Available Gases
8.5 Nitrogen (N2): Used to purge out room air and keep the process tube in an inert atmosphere.
8.6 Oxygen (O2): Used for dry/wet oxidation.
8.7 TCA (C2H3Cl3): Used for in-situ process tube cleaning.
8.8 Nitrogen Carrier (N2cARR): Used to carry TCA vapor to the process tube.
Process Notes
8.9 Wafer cleaning requirements before loading into TYLAN furnaces (See also Chapter 5.0)
8.9.1 Photo-resist on the wafer surface must be stripped first in PRS3000 bath of Sink5,
Technics-C, or Matrix. Then cleaned in Sink8 (4”) piranha bath. New wafers can skip this
step.
8.9.2 All wafers then cleaned in Sink6 piranha bath. Wafers just unloaded from an MOS
furnace can be loaded into another furnace without further cleaning.
8.10 Additional wafer requirement for the MOS furnaces: Only new wafers and wafers processed only
in MOS clean furnaces can be loaded into a MOS furnace after cleaning. Wafers that have been
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tylan5 Chapter 5.5
processed in a Non-MOS furnace or have gone through any Non-MOS processes can not be
loaded into any MOS furnace. ABSOLUTELY NO EXCEPTION.
8.11 No wafer processed with any metal films, even the film is stripped or covered, is not allowed in
TYLAN5.
9.0 Overall Furnace Operation
9.1 General TYLAN Furnace Information
The TYLAN Furnace consists of three basic modules: Load Station Module, Furnace Module, and
Source Cabinet Module. Microlab members have access to the Load Station Module in the clean
room area. The other two modules are in the Tylan service chase. Only Microlab staff with proper
training has access to these two modules due to potential hazards.
The Load Station Module houses a laminar flow unit with HEPA filter for clean air distribution. A
Boat Loader Unit opens/closes the furnace door and pulls-out/pushes-in the cantilevers with
wafer boats sitting on top. The operation can be automatically controlled by a process recipe, or
manually using the ROP (see Section 9.3).
The Furnace Module consists of a quartz process tube, thermal couples, and heating elements. It
is divided into three zones: Load, Center, and Source. The temperature is controlled through a
PID electronic board (DTC). All the control parameters can be set in the process recipe. The
volume of the quartz tube is approximately 25 liters. The process gas flows into the tube from the
Source end and vented through a hole on the Load end.
The Source Cabinet Module contains several Mass Flow Controllers (MFC), which regulate the
process gas flows, and the TCA bubbler.
9.2 TYCOM Terminal
The TYCOM Terminal controls/monitors all the TYLAN/TYSTAR Furnace operations. It consists
of a CPU with two floppy disk drives, a CRT monitor and a keyboard. Disk drive #2, on the right
side, is used for viewing and loading of recipes. The auxiliary drive is used for copying diskettes.
The floppy disk used has a special format. All the standard TYLAN5 recipes are store on the
diskette labeled STANDARD DISK. Please ask staff if you need one to store your customized
recipes.
9.2.1 TYCOM commands – TYCOM CPU only recognizes CAPITAL letters only. You can use
the numerical key pad on the right hand side of the keyboard to enter numbers. However,
do not use the [Enter] key on the numerical key pad. It will cause error when loading a
recipe.
Commands Function Example
DI DI
Displays the recipe directory of the
diskette in Drive #2
DI RE recipe name
Displays the content of a recipe on
the diskette in Drive #2
DI RE DRYOXA
LO recipe name # Load a recipe to a TYLAN furnace LO DRYOXA
DI ST #
Displays current status of a TYLAN
furnace (see Section 9.2.2)
DI ST 5
DI DE #
Displays the system configuration of
a TYLAN furnace
DI DE 5
DI AL #
Displays previous process alarms of
a TYLAN furnace
DI AL 5
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tylan5 Chapter 5.5
9.2.2 Display Furnace Status - When you use DI ST commands, the CRT monitor displays the
status of the TYLAN furnace. This information is very important, especially for equipment
problem diagnosis. The following example is used to explain the information users should
know. The furnace status to be displayed is TYLAN5 with recipe HIN2ANNL loaded but
not running (Idle state).
02/023/07 16:30:32
*=DISABLED
TUBE STATUS PROCID ET STEP TIME-TO-GO STEP ET
005 READY HIN2ANNL 00:00:00 0000 00:00:00 00:00:00
OUTPUTS RELAYOUT RELAYIN INPUTS
N2 = 0.9 N2 = ON CCIN1 = OFF TEMPL = H 750.2 2118
ANA02 = 0 CCOUT2 = OFF O2PRS = OFF TEMPC = G 750.5 0632
O2 = .0 O2 = OFF CCIN3 = OFF TEMPS = G 749.5 0895
N2CARR = .0 N2CARR = OFF CCIN4 = OFF CALIBL = 752.1
ANA05 = .0 VENT = OFF CCIN5 = OFF CALIBC = 750.9
ANA06 = .0 CCOUT6 = OFF BPIN = ON CALIBS = 747.3
ANA07 = .0 CCOUT7 = OFF BPOUT = OFF
ANA08 = .0 TCA = OFF CCIN8 = OFF
TEMPL = 750.0 CCOUT9 = OFF N2 = G 0.9
TEMPC = 750.0 CCOUT10 = OFF ANA02 = G .0
TEMPS = 750.0 CCOUT11 = OFF O2 = G .0
CCOUT12 = OFF N2CARR = G .0
CCOUT13 = OFF
DTCENA = ON
LOAD = OFF
UNLOAD = OFF
The following sections explain the above display in details.
Display Header (first 4 rows)
The first row shows the current Data and Time stored in TYCOM CPU. The second row
indicates that any INPUT or OUTPUT followed by an * on the display is disabled. None of
the INPUT and OUTPUT of TYLAN5 is disabled. On the third and fourth lines:
TUBE - - - - - - - TYLAN furnace #.
STATUS - - - - - READY (idle, recipe loaded but not running)
RUN (recipe running)
HOLD (recipe hold at certain step)
STNBY (no recipe loaded, indicate power failure)
PROCID - - - - - Recipe ID, stated in the first line of the recipe, usually the same as
the recipe file name.
ET - - - - - - - - - Total time elapsed since the process starts.
STEP - - - - - - - Current recipe step.
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tylan5 Chapter 5.5
TIME-TO-GO - -Time left to run in the current step.
STEP ET - - - - Time elapsed in the current step.
OUTPUTS – Process settings sent from TYCOM CPU to a TYLAN furnace.
N2CARR, N2, O2 - - - - - - - - - - Process gas flow settings
TEMPL, TEMPC, TEMPS - - - - Temperature settings for Load, Center, and
Source Zone
ANA0# - - - - - - - - - - - - - - - - - Available for future use.
RELAYOUT – Commands sent to furnace Contact Closure Switches.
N2CARR, N2, O2 - ----- Turn on/off the NUPRO valves of individual process
gas. If off, no process gas flows regardless what the flow setting is.
TCA - - - - - - - - When ON, N2CARR flows through the TLC liquid reservoir,
then into the process tube, carrying the TLC vapor to clean the
contamination. When OFF, N2CARR flow directly into the quartz tube without
TLC.
DTCENA - - - - Turns on the DTC board for furnace temperature control.
Every recipe must have DTCENA=ON statement in step 0001.
CCOUT# - - - - Available for future use.
RELAYIN – Contact Closure Sensor inputs from a TYLA furnace to TYCOM CPU. When
a process is running after the furnace door closes, only BPIN should be ON. All other
RELAYIN should be OFF.
O2PRSAL - - - - Low oxygen Pressure Alarm.
BPIN/BPOUT - Boat cantilever at IN and OUT position.
CCIN#- - - - - - - Available for future use.
INPUTS – Actual Temperature and Gas Flow readings from furnace thermal couples and
mass flow controllers.
TEMPL, TEMPC, TEMPS - - - - -Actual temperature readings of Load,
Center, and Source zones. A letter (H, G, L) in front of the temperature
reading indicates whether the temperature is in the tolerance band set in the
recipe. The 4-digits number, follows the temperature reading, represents
electric power sent to each zone. The maximum power is 4095.
CALIBL, CALIBC, CALIBS - - - - Calibrated temperature readings. If these
readings differ from TEMPL, TEMPC, TEMPS by 2ºC, the process
temperature may not stabilize. Report the problem on the WAND.
N2CARR, N2, O2 - - - - - - - - - - Actual process gas flows. A letter (H, G, L)
in front of the flow reading indicates whether the flow is in the tolerance band
set in the recipe. If no tolerance is set, it is assumed that the tolerance is
infinite, and the letter G appears all the time.
9.2.3 Display Process Alarms – There is no special abort sequence for the TYLAN
Atmospheric Furnace. To make sure that your process completes without any problem,
the user should check the process run history by enter DI AL # command at TYCOM
terminal. Due to the limited memory of the TYCOM CPU, the alarm history clears if the
memory is full.
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tylan5 Chapter 5.5
9.3 Remote Operating Panel (ROP)
Every TYLAN furnace has a Remote Operating Panel (ROP) that is located next to its Load
Station Module. The ROP is used to perform all the process operation after recipe loading at
TYCOM terminal. It consists of two thumb wheels to control the boat loader speed, a LED display
panel, several LED lights, and buttons. Their functions are explained in the following sections.
9.3.1 Furnace Zone Firing LED –One the lower left corner of the ROP, there are three LED
for three zones of the furnace. One flash on the LED means one electric current pulse
flows through the heating element of the furnace zone.
9.3.2 Boat Control – The process recipe can only ask for boat in and out but not the
loading/unloading speed. The speed is set by the two thumb wheels located on the upper
left side of the ROP. There are three buttons under the thumb wheels, (labeled IN, OUT,
and STOP) that can be used to control the boat manually.
9.3.3 Hardware Alarm – On the ROP, there are two more LED (Labeled OT and SCR). Both
of them are hardware temperature control alarms. If either one is on, press the [Alarm
Ack] button next to them to silence the alarm, then contact staff immediately. During nonoffice
hours, abort process, then report problem on WAND.
9.3.4 LED Display Panel and Numerical Pad – On the right side of the ROP, there is a LED
display panel and a Numerical pad. The LED Display Panel cycles through the following
furnace information when the [7|Status] button on the numerical pad is pressed.
Process Status: READY Idle status, recipe loaded but not running (holding at step
0001 of the recipe)
END Process ends. Press [Alarm Ack] to silence the alarm and
return to READY status.
STNBY Standby status, recipe lost due to power failure or furnace
computer reset. A recipe needs be loaded; otherwise the
furnace cools down with all gases shut off.
RUN A process recipe is currently running.
Recipe Name: The Process ID that appears on the first line of the recipe. Usually the
same as the recipe file name.
STEP: The current step number of the running recipe.
Time: Time to go in current process step (HH:MM:SS)
Temperature: -Average temperature of the three furnace zones.
Note: Do not press other numeric buttons which are designed for the industrial
manufacturing use. If press by mistake, the LED display panel may not function
properly. Press [Clear], then [7/Status] button to clear this problem.
9.3.5 Process Operation Buttons – There are four buttons, on the right side of the ROP, for
process control. Their function and corresponding TYCOM commands are listed in the
following table.
ROP button TYCOM command Function
[Recipe|Run] RU # Run the loaded recipe
[Hold|Clock] HO # Hold the process at current recipe step
[Alarm|Ack] AC #
Silence the process end alarm, returns the furnace to
READY
Skip to next process step (works only IF ALMACK=ON GOTO
#### is in the current process step)
[Abort] AB # Abort the current process, the furnace skip to END state
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tylan5 Chapter 5.5
9.4 Available Recipes
9.4.1 Gate Oxidation: SGATEOX
9.4.2 Dry Oxidation: DRYOX
9.4.3 Nitrogen Annealing: N2ANNLA, HIN2ANA
9.4.4 Tube Cleaning: TCA
9.5 Processing a Run
Loading a Recipe
9.5.1 Enable the TYLAN furnace.
9.5.2 Check that no recipe is running in furnace and the ROP displays READY.
9.5.3 Insert the recipe diskette for the furnace into floppy drive #2, right hand side, of TYCOM
CPU.
9.5.4 If you are not sure of the recipe name, enter DI DI at TYCOM Terminal to display the
recipe directory.
9.5.5 Enter LO recipe-name #, then press the [enter] key.
9.5.6 Enter the process parameters when prompted. You can use the numeric key pad on the
keyboard. But not the [enter] key on the right end of the numeric keypad. TYCOM does
not recognize that key, and will not load the recipe.
9.5.7 TYCOM Terminal displays RECIPE LOADED SUCCESSFULLY if there no error in the
recipe and parameter entries.
(Do not use TYCOM command RU # to start the process, because someone may be
loading/unloading wafers on another furnace of the same bank. Besides, it is
recommended that you check the ROP to make sure the recipe is loaded into the
furnace.)
Load wafers and run a process recipe
9.5.8 Go to the front of the load station module of the TYLAN furnace. Press [7|Status] button
on the ROP to make sure the furnace is at READY state and the recipe name is correct.
9.5.9 Put on the face shield. Then press [Recipe|Run] button. The furnace door will open and
the wafer boats come out. The door will close automatically after 20 minutes. If the boats
start moving in and you need more time loading wafers, press [Alarm Ack] button on the
ROP before the door closes, the boats will move out again and you have another 20
minutes.
9.5.10 Transfer your wafers from Sink6 to the furnace in a BLUE wafer box. See Section 8.9 for
wafer cleaning requirement.
9.5.11 Load MOS clean wafers using the MOS clean vacuum wand with red tubing. All the
wafers should be loaded with flat up for better wafer support and consistency run-to-run
results.
9.5.12 Do not wear poly gloves over clean room gloves when loading/unloading wafers. The
poly gloves usually are too big and slippery. The tips of the poly glove may melt on the
hot quartz ware and cause contamination, which is hard to notice, because it is colorless
and transparent. The poly gloves should be used at sinks and other room temperature
operations only.
9.5.13 After loading wafers, press [Alarm Ack] button on the ROP. The boat will start moving into
the furnace. If you want to add/remove or reposition wafers before the door closes, press
[Alarm Ack] once, the boat will move out again.
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tylan5 Chapter 5.5
Unload wafers after process ends
9.5.14 When the process reaches the last step, the ROP displays END and the alarm beeps.
Press [Alarm Ack] button to silence the alarm and reset the furnace to READY state.
9.5.15 To unload your wafers, press [Recipe|Run] button again, and the boats will move out.
When the boats stop moving, wait a few minutes for wafers to cool down. Then use the
appropriate vacuum wand to unload your wafers to the quartz boat on the cooling rack
next to the furnace. The wafers may still be too hot for the plastic wafer box.
9.5.16 Press [Alarm Ack] button to move the boats in. Press [Abort] button, then [Alarm Ack],
and the furnace returns to READY state.
9.5.17 Disable the TYLAN furnace on the WAND. Unload wafers from the cooling rack into
wafer a box.
10.0 Troubleshooting Guidelines
10.0 TYCOM Terminal is blank
10.0.1 Press [Enter] key. The terminal may be at sleep mode.
10.0.2 Turn the terminal off, then on. This will reset the terminal. Adjust brightness/contrast if
needed.
10.0.3 If both of the above steps do not work, the TYCOM CPU needs reset (Section 10.2).
10.1 Reset TYCOM Terminal
10.1.1 Slide the TYCOM CPU out slowly.
10.1.2 On the backside (up left corner facing the CPU), there is a black square power switch.
Toggle the switch off then on.
10.1.3 Check all the wires connected to the backside of the CPU are secured. Slide back the
CPU slowly.
10.1.4 On TYCOM terminal, Enter ACT PR, then [Enter].
10.1.5 Enter IN DA dd/mm/yy; enter IN TI hh:mm:ss to set the date/time.
10.2 I/O error – There is a communication problem between the TYCOM CPU and the furnaces.
Report problem on WAND.
10.3 Door will not open/Boat loader stuck
10.3.1 Make sure there is nothing obstructs the movement of the boat loader.
10.3.2 Make sure the cable that pulls the boat loader is not loose. If so, ask staff to adjust the
tension of the cable.
10.3.3 Try to move the boat loader manually. (Section 9.3.3)
10.3.4 If the boat loader stuck on the track, give it a little pull/push help it overcome some
friction. Do not use excessive force.
10.3.5 If all the above step fail, report problem on WAND.
10.4 OT/SCR alarm is ON – The furnace electronic board can not control the temperature. Silence the
alarm. Find Staff immediately. During off hours, abort process and report problem on WAND.
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tylan5 Chapter 5.5
TYLAN Atmospheric Furnace Study Guide
Be sure to know…
1. Maximum temperature.
2. MOS vs. non-MOS rule.
3. Loading and changing a recipe.
4. TCA cleaning: when, why and how to do it.
5. Troubleshooting the TYCOM screen.
6. Cleaning wafers before they go into the furnace.
7. Sending recipes to the furnace.
8. Wafer loading into boats and into the tube.
9. Displaying the status of a process.
10. Unloading wafers and closing the tube.
11. Which vacuum wand to use at which furnace.
12. Alarms and what to do when you hear them.
13. Preventing contamination in the VLSI.
14. Positioning wafers in boats: why and how.
15. Which furnace uses which gas(es).
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