(tystar1)
1.0
Title
Tystar1 MOS Clean Gate Oxidation Atmospheric Furnace (4” and 6”)
(Tystar1)
2.0
Purpose
Provide specific operation and process information for Tystar1
atmospheric MOS clean (gate oxidation) furnace that is capable of processing
both 4” and 6” wafers. This tube is specifically assigned to gate oxidation
(MOS devices) process.
3.0
Scope
This chapter covers the general furnace description for Tystar1,
TYCOM and furnace operation procedure, which includes process recipe loading,
wafer loading/unloading, process status monitor, user level problem diagnosis,
and wafer cleaning requirements.
4.0
Applicable Documents
4.1
Tylan 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-Trichloroethane), TLC
(trans 1, 2-Dichloroethene), Oxygen, Nitrogen, and Forming Gas H2/N2
(copies in the lobby).
5.0
Definitions & Process Terminology
5.1
ROP: Remote-Operation Panel
5.2
DNTLK: Door interlock, if door is not closed, no process gas can flow.
5.3
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
this 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.
5.4
Gate Oxidation: A special dry oxidation (O2)
process that produces high quality silicon oxide film (well controlled
thickness, and process).
5.5
Dry/Wet Oxidation: A high temperature
oxidation (dry O2 or steam) process that oxidize the underlying silicon
to forms silicon oxide. Dry oxidation uses oxygen for better process control.
Wet oxidation uses both DI water and oxygen for fast reaction rate.
5.6
Annealing: A high temperature process that uses nitrogen to keep wafers in
an inert atmosphere.
5.7
TLC/TCA Cleaning: A high temperature process that uses
TLC/TCA and oxygen to clean the furnace quartz parts and interior, by removing
possible metallic contaminants in these areas. Currently, Tystar1 uses TCA
cleaning.
5.8
Furnace Flat Zone: An area inside the furnace with least
temperature variation across it (best place to process wafers).
6.0
Safety
Follow general safety guidelines in the lab as well as the
specific safety rules, listed below:
6.1
Electric Shock Hazard: Tystar 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: TLC (trans 1, 2-Dichloroethene) is used
for in-situ cleaning of quartz wares. TLC poses moderate health and high fire hazards.
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 any furnace quartz ware to prevent burning your hands, as well
as contaminating the furnace. No flammable chemical, especially organic
solvents are allowed at the load station, when the tube is open.
6.4
The process staff must check all new recipes, before they can be
used on any Tystar furnace. Customized recipes should be stored on a separate
diskette (user’s diskette), not on the standard furnace diskette(s).
7.0
Statistical/Process Data
7.1 Microlab web page.
7.2 Problem and comment section, under the
equipment menu of the wand.
7.3 Enable message for individual Tystar
furnace.
8.0
Available Process, Gases, Process Notes
8.1
Wafer Cleaning Requirements, before loading them into Tystar
furnaces.
8.1.1
Photoresist on the wafers must be stripped first in PRS3000 bath
(Sink5) or Technics-c or Matrix Asher, then cleaned in Sink8 (4”). More
cleaning may be required as per follows.
8.1.2
Wafers going into any furnace, regardless of their clean
categories (MOS or Non-MOS clean), must see MOS clean, last. This means every
wafer needs to be cleaned in Sink6 (4”) prior to getting loaded onto Tystar
furnace(s). This rule also applies to start wafers (fresh out of the vendor’s
box). Non-MOS wafers (MEMS, so on) require a Non-MOS clean step prelude to the
above-mentioned MOS clean step.
8.1.3
No cleaning steps (NONE!) are necessary for wafer(s) just
unloaded from one MOS furnace and going straight into another MOS furnace.
Similarly, for wafer(s) just unloaded from one Non-MOS clean furnace and going
straight into another Non-MOS furnace, NO INTERMEDIATE CLEANING STEP is
required.
8.2
Wafers processed in a Non-MOS furnace or wafers which have gone
through any Non-MOS processes, shall not be loaded into MOS furnaces. There is ABSOLUTELY
NO EXCEPTION to this rule.
Available Processes
8.3
Tystar1: MOS furnace Dedicated for gate oxidation.
8.4
TCA clean: Available for Tystar1 only.
Available Gases
8.5
Nitrogen (N2): Used to purge out room air and keep the
process tube in an inert/clean atmosphere.
8.6
Oxygen (O2): Used for dry/wet oxidation process.
8.7
DI Water Vapor (H2OVAP): Used for wet oxidation.
8.8
Forming Gas (H2/N2): Not available yet.
8.9
Argon (Ar): Not available yet.
8.10
TCA: Used for in-situ process tube cleaning.
8.11
Nitrogen Carrier (N2CARR): Used to carry TLC vapor to
the process tube.
Special Process Notes
8.12
Tystar1 should be used for gate oxidation ONLY. However, in the
event that Tystar2 may be out of service, and there are no other MOS clean
furnace(s) available, then Tystar1 may be used as a backup to Tystar2 (dry/wet
oxidation and/or anneal). This requires process engineering or Microlab manager
permission (Sia/Katalin).
8.13 Absolutely, no
wafer(s) with metal on them are allowed in Tystar1.
8.14 After TCA
process, please check the MFS460 alarm. If you do not know where it is located,
ask staff for help. If the MFS460 is alarming, no process gas, except N2,
can flow for your process.
9.0
Overall Furnace Operation
9.1
General Tystar Furnace Operational Guidelines
The Tystar Furnace consists of three basic modules: Load Station
Module, Furnace Module, and Source Cabinet Module. Microlab users are permitted
to access the Load Station Module, only (clean room area). Source cabinet and
furnace module access are reserved for trained staff, and should not be touched
by Microlab users (chase area). Failure to do so, could pose potential
hazard(s).
The Load Station Module (in the clean room area) houses a laminar
flow unit with HEPA filters for clean air distribution. A Boat Loader Unit
opens/closes the furnace door and pulls-out/pushes-in the cantilever rods, upon
which the boats are waiting to receive work wafers. The boat loader operation
can automatically be controlled by a process recipe, or manually controlled by
using the ROP’s command keys (see Section 9.3, below).
The Furnace Module consists of a quartz process tube,
thermocouples, and heating element. Furnace Flat Zone is divided into three
sections: 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 45 liters. The process
gas is flown into the tube from the “source” end, and vented through the holes
in the “Load” end of the furnace.
The Source Cabinet Module contains several units: the Mass Flow
Controllers (MFCs) for process gas flow regulation; the DI water vapor
generator for steam generation; and the TLC bubbler for tube cleaning purpose.
An electronic gas control system, referred to as MFS 460, controls/coordinates
all MFCs and interlocks. This unit is designed to ensure safe furnace
operation. Authorized staffs are the only people allowed to access this unit,
which is located at the back of the furnace (service chase area).
9.2
TYCOM Terminal (loading recipes onto ROP and looking at status
of run in progress)
The TYCOM Terminal controls and monitors
all Tystar Furnace operational steps through process recipe(s). This unit
consists of a CPU with two floppy disk drives, a CRT monitor and a keyboard.
The auxiliary drive #1 is used for copying diskettes. This unit can copy the
entire content of a diskettes, hence, care must be taken not to overwrite
MIcrolab standard process diskette(s). Disk drive #2, on the right hand side of
TYCOM terminal could be used for viewing or loading the recipes onto remote
control panel unit in front of the tube. This drive is also used for single
recipe copying/editing, and by temporarily storing the recipe content onto the
computer memory, performing the edit task, and ultimately copying the recipe
back onto the diskette in its final form. The standard recipe(s) for an
individual furnace is stored on a designated floppy diskette, labeled with the
furnace name, e.g. Tystar1. Each floppy disk has a special format and is
assigned to a particular tube. Please consult with staff, whenever you need to
generate customized recipe(s), specific to your need. Keep your recipes on a
separate diskette, away from dedicated furnace diskette(s) and do not alter
content of these dedicated furnace recipe diskette(s).
TYCOM Commands
TYCOM CPU only recognizes CAPITAL letters. You can also use the
numerical keypad located on the right hand side of the keyboard, however, be
aware that the [Enter] key on the numerical keypad is not recognized by the
computer. This particular key can cause errors, when loading a recipe.
Various functions can be invoked through TYCOM commands listed on
the following table (1st column).
|
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 1SWETOXA |
|
LO “recipe
name” “#” |
Load a recipe to a Tystar furnace. |
LO 2SDRYOXA 2 |
|
DI ST “#” |
Displays current status of a Tystar furnace (see Section 9.2.1). |
DI ST 3 |
|
DI DE “#” |
Displays the system configuration of a Tystar furnace. |
DI DE 3 |
|
DI AL “#” |
Displays previous process alarms of a Tystar furnace. |
DI AL 4 |
9.2.1
Display Furnace Status
When you use DI ST commands, the CRT monitor displays the status
of the Tystar furnace. This information is very important, especially for
equipment problem diagnosis. The following example further explains the Display
Furnace Status page, and any Tystar qualified users are expected to understand
this display, as it is described below.
Snap shot of Tystar2 furnace status page
is displayed below, where “2SWETOXA” recipe is loaded onto the tube, and the
furnace is in an idle mode.
|
05/05/02 |
16:30:32 |
|
|
|
|
|
|
|
|
|
|
* = DISABLED |
|
|
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|
|
|
|
TUBE |
STATUS |
PROCID |
|
ET |
|
STEP |
TIME-TO-GO |
STEP ET |
|
|
002 |
READY |
2SWETOXA |
|
00:00:00 |
|
0000 |
00:00:00 |
00:00:00 |
|
|
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|
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|
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|
OUTPUTS |
RELAYOUT |
RELAYIN |
INPUTS |
|
|
||||
|
N2CARR = |
100.0 |
N2CARR = |
ON |
DNTLK = |
OFF |
TEMPL = |
H |
752.3 |
0880 |
|
N2 = |
3000.0 |
N2 = |
ON |
H2ORDY = |
OFF |
TEMPC = |
G |
751.0 |
0726 |
|
H2/N2 = |
.0 |
H2/N2 = |
OFF |
TAPERDY = |
OFF |
TEMPS = |
L |
747.2 |
0744 |
|
O2 = |
.0 |
O2 = |
OFF |
N2PRSAL = |
OFF |
CALIBL = |
|
752.1 |
|
|
AR = |
.0 |
AR = |
OFF |
TLCALM = |
OFF |
CALIBC = |
|
750.9 |
|
|
ANAO6 = |
.0 |
H2OVAP = |
OFF |
BPIN = |
ON |
CALIBS = |
|
747.3 |
|
|
SPEED = |
.0 |
TLC = |
OFF |
BPOUT = |
OFF |
|
|
|
|
|
ANAO8 = |
.0 |
H2OPUR = |
OFF |
H2OLEAK = |
OFF |
|
|
|
|
|
TEMPL = |
750.0 |
H2OHTR = |
OFF |
|
|
N2CARR = |
G |
99.9 |
|
|
TEMPC = |
750.0 |
H2OTAPE = |
OFF |
|
|
N2 = |
G |
3000.5 |
|
|
TEMPS = |
750.0 |
CCOUT11 = |
OFF |
|
|
H2/N2 = |
G |
0.2 |
|
|
|
|
CCOUT12 = |
OFF |
|
|
O2 = | |||