OAI 200 Series User manual

OPERATION MANUAL
Model 200
MASK ALIGNER
TABLE TOP SERIES
685 RIVER OAKS PARKWAY
SAN JOSE, CA 95134
www.oainet.com
[email protected]
408/232-0600
P/N 0200-750-01, Rev. B
05/29/01

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Table of Contents
Section 1: Introduction..................................................................................3
Scope.......................................................................................................3
Certification ..............................................................................................3
Warranty and Assistance..........................................................................3
Return Policy............................................................................................4
Unpacking and Inspection........................................................................4
Section 2: Components of the Series 200 ...................................................5
Introduction...............................................................................................5
The Alignment Module..............................................................................5
The Exposure System..............................................................................6
The Light Sources...............................................................................6
The Regulated, Power-adjustable Power Supply................................6
The Constant Intensity Controller ........................................................6
Shutter Timer/Field Illumination Control ..............................................6
Alignment Optics......................................................................................7
Operating controls....................................................................................7
Section 3: Installation Instructions ..............................................................8
Alignment Module.....................................................................................8
Light Source.............................................................................................8
Installing the microscope..........................................................................9
Installing the Constant Intensity Controller...............................................9
Preparing the Console..............................................................................9
Section 4: Operating Instructions ..............................................................10
Controls and Indicators...........................................................................10
Installing the Photomask ........................................................................10
Placing the Substrate on the Vacuum Chuck and Alignment .................10
Exposing the Substrate ..........................................................................12
Section 5: Aligning the Microscope to the Alignment Module ................13
Aligning the Microscope to the Alignment Module..................................13
Section 6: Trouble Shooting.......................................................................14
Series 200 Specifications............................................................................15
Model 200 Figures........................................................................................17
Figure 1. Electrical Interconnection Diagram
Figure 2. Rear Panel Connections
Figure 3. Controls and Indicators
Section 7: Drawings/Schmatics..................................................................19

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SECTION 1:
INTRODUCTION
Scope of this Manual
This Operation Manual describes installation, calibration, operation, and maintenance
of the OAI Series 200 Mask Alignment and exposure system.
Certification
OAI certifies that each Series 200 aligner met or exceeded its technical specifications at
the time of shipment. The system is equipped with a Constant Intensity Controller which
was calibrated in simulation testing to ensure that the optical sensing loop is properly
calibrated with reference to NIST traceable measurement standards. All control and
measurement functions were tested to verify proper operation.
Warranty and Assistance
This product is warranted against defects in materials and workmanship for a period of
six months or 4000 hours (whichever occurs first) following shipment from the factory
provided that installation has been performed or supervised by personnel trained on the
Series 200 Mask Alignment and Exposure System. Equipment that in OAI's sole opinion
has been misused, abused, incorrectly operated, improperly connected to a power supply,
or tampered with shall be denied warranty benefits. Broken factory seals on instruments
or power supplies (if the aligner is so equipped) shall be sufficient evidence to void the
warranty protection. If the product is found defective within the warranty period mentioned
above, OAI shall have the option to replace it or to repair it without charge and shall
assume only one-way shipping charges. No other warranty is expressed or implied. No
agent or representative has the power to alter or extend OAI's liability as herein stated.
Determination of the suitability of the product or its fitness to a particular purpose lies
solely with the buyer. In no case shall OAI assume liability for any incidental or
consequential damages or expenses. In addition to the remedies herein provided, the
buyer may have other rights, which vary according to local laws.

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Return Policy
1. Notify OAI before returning any product to the factory and obtain a Return
Materials Authorization number. No credits, allowances, or adjustments will be
made until reported defects have been verified to the satisfaction of OAI.
2. Time spent by OAI in checking equipment that is found to have no defects may be
chargeable, warranty status not withstanding. Equipment returned to OAI for
warranty service shall be shipped with transportation prepaid by the buyer. OAI
will prepay the shipment back to the buyer. OAI reserves the right to refuse collect
shipments, or to impose a service charge in addition to all C.O.D. costs.
3. Repairs and calibration services, other than warranty, available at prevailing OAI
rates. In such cases the buyer shall pay transportation costs both ways for such
services.
Unpacking and Inspection
If the shipping container shows evidence of damage, ask that the carrier's agent be
present when the equipment is unpacked. Look for obvious damage, such as
scratches, dents, broken faceplates, etc. If the equipment has been damaged, save
the shipping and packing materials for the carrier's inspection and contact OAI
immediately. OAI will replace products, which have been verifiably damaged during
shipping without waiting for the carrier's insurance settlement (subject to product
availability.)

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SECTION 2:
COMPONENTS OF THE SERIES 200
Introduction
The OAI Series 200 Mask Alignment and Exposure System can be configured to
accommodate a wide variety of substrate sizes, shapes and materials from pieces of
substrates up to 6" diameter wafers or even 6"x6" square substrates. The system can
handle masks from 2"x2" to 7"x7". It is capable of resolution of one-micron structures with
overlay accuracy of 0.2 microns.
The Series 200 consists of a console that holds the alignment module, alignment
optics and transport platform, and light source. The Constant Intensity Controller is
separate from the console.
This tabletop system may be mounted on pneumatic spring vibration isolators to
facilitate alignment of very small structures. (Note: It is possible that there may be
vibrations in any given facility which are of period or amplitude beyond the capability of any
given vibration isolation system to eliminate. In such a case, the user should contract a
vibration survey and obtain vibration isolation designed for the specific environment.)
Unique applications and requirements may be accommodated by means of custom
designed components.
The Alignment Module
The alignment module has a sturdy mask frame, which is always in three-point contact
with the alignment module casting during exposure to insure that the mask is
perpendicular to the axis of illumination. The mask is held in place by vacuum and is
assisted, if necessary by a set of clamps, which hold the mask, and contacts it around the
edge. This Mask Clamp is held by a fastener. Mask Holders can be fabricated to
accommodate glass, mylar, and other masking materials.
The mask is mounted on top of the mask frame so that the mask cannot fall onto the
substrate or shift from its proper position if vacuum is lost. Mask rotation is provided to
align the array of patterns on the mask with the x-axis of the microscope travel and to allow
compensation for mask array rotation error.
The components of the alignment module are mounted on a rigid casting. Micrometer
controlled X, Y, Theta and Z are totally independent of each other. The substrate vacuum
chuck is mounted on a pre-loaded bearing assembly to eliminate play in the X-Y plane and
it can be quickly removed and replaced by vacuum chucks designed for substrates of
different size, shape, or thickness.
The alignment module is mounted to the slide assembly at three points and can be
adjusted to level the mask frame to the alignment microscope.

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The Exposure System
The Light Sources
UV exposure systems available for the 200 Series offer a broad range of exposure
areas, intensities, and spectral profiles to match the user's photoresist. They range in
power from 200 to 2000 watts producing radiation from 220nm to 436nm. Areas from 1" to
6" may be uniformly exposed. These highly collimated light sources provide excellent
results for contact or proximity exposure of photoresist.
The Regulated, Power-Adjustable Power Supply
These power supplies holds lamp power to within 1% over power variations as great as
±15% VAC. The power supply can be adjusted over a limited range of power.
The Constant Intensity Controller
The Constant Intensity Controller (CIC) holds lamp intensity to within ±2% of the
operator set intensity value at the exposure plane and compensates for lamp aging and
power variations as great as ±15% VAC. The CIC uses a closed loop feedback control
system having two sensors each tuned to a user selected wavelength. When in the
Constant Intensity mode, the CIC monitors one of the two sensors mounted in the light
source and adjusts the intensity in response to changes in the lamp's output. The operator
selects the wavelength to be monitored by use of a selector switch on the front of the CIC.
Shutter Timer/Field Illumination Control
The shutter timer allows the user to set exposure times in 0.1 second increments from
0.1 seconds to 99.9 seconds and in one second increments from 1 to 999 second
increments. It also provides 6 VAC for microscope illumination.
The shutter timer provides power to the shutter solenoid during the exposure interval.
The exposure interval can be initiated by pressing the "Expose" button on the shutter timer
or remotely by a trigger signal supplied when the alignment module reached the exposure
position.
Alignment Optics

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A wide variety of alignment optics is available including stereo zoom, compound, split
field microscopes and CCTV systems. This variety allows the user to choose a system,
which is best, suited to his specific needs.
The microscope is moved from its home position to the alignment position by use of the
handle on the sliding base located at the far right side of the aligner. The alignment
module is moved in the "X" direction and the microscope is moved in the "Y" direction to
position alignment structures in the field of view.
Adjustments are provided to level the microscope to the photomask so that it is in focus
across the entire photomask.
A fine focus adjustment is provided to insure the sharpest possible image during
alignment.
Operating Controls
All operator controls are mounted on the front of the aligner. They are clearly labeled to
identify their function.

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SECTION 3:
INSTALLATION INSTRUCTIONS
NOTE: Before beginning installation, read "unpacking and Inspection"
in the introduction.
Alignment Module
The alignment module is installed at the factory so that it is properly aligned to the light
source and microscope. It is possible for it to be dislodged during shipment and to require
adjustment. Prior to any adjustment the module must be unpacked.
1. Remove the tie-wrap from the alignment module and lift the mask frame to remove
the foam pad from under the mask frame lock and from around the vacuum chuck
seat.
2. Remove the foam blocks from between the tips of the X and Y micrometers and the
reference surfaces on the X-Y stage.
3. The alignment module is attached to the slide platform by three 1/4-20 mounting
bolts. There are two at the back of the module and one at the front. They provide
adjustment to level the alignment module in X and Y and can be adjusted from
underneath the frame.
Light Source
There is packing material in the light source, which is placed there to prevent damage
to the system. The packing material is placed around both mirrors and on both sides of
the lens. Remove it.
1. Install the lamp, with its heat sink, according to the instructions in the Series 30
Light Source manual.
2. Check to insure that the light source is centered over the alignment module. If it is
not, the light source may be moved slightly by loosening the four bolts in the base
plate and adjusting the position. The alignment module may also be moved slightly
by loosening it's mounting bolts.
3. Insure that the primary mirror has been secured in the 45° position. If it has not
been, the heat sensor under the mirror will turn the lamp off.

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Installing the Microscope
1. Unpack the microscope and assemble it according to the manufacturers
instructions supplied with the microscope. (There is a steel pin attached to the
back of the microscope mount. The center of the microscope focus range is
determined by the position of this pin and it has been properly installed at the
factory.)
2. Insert the pin into the anodized shaft of the transport mechanism and tighten the
retaining bolt. (NOTE: The transport mechanism has been secured by tape, which
prevents movement of the Y stage and by a clamp on the bearing shaft below the
front of the transport stage. The clamp has a tag on it instructing the user to
remove it before operating the system. Remove the tape and the clamp.)
3. Install eyepieces and objectives as appropriate.
Installing the Constant Intensity Controller
1. Remove the Constant Intensity Controller from its packing.
2. Connect the cables as shown in Figure 1 and the instructions in the Constant
Intensity Controller manual.
Preparing the Console
1. Connect all vacuum, air, and nitrogen lines as shown in Figure 2. Turn on the air
and nitrogen and adjust your regulator to 60 PSI.
2. The pressure for the Acculign functions (substrate lift and floating the ball seat)
have been adjusted at the factory assuming that 60 PSI have been provided. If
further adjustment is necessary; the adjustment valves are mounted on the bottom
side of the system's base plate.
3. Check the safety and air interlock by raising the mask frame. There should be a
brief hiss of air exhausting. The mask frame will not rise if the alignment optics is
not in the full rear position and the interlock switch closed. This is to prevent the
mask from hitting the optics when raising.
4. Check all electrical connections and plug in the main power line.

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SECTION 4:
OPERATING INSTRUCTIONS
Controls and Indicators
The controls and indicators are shown and their functions are described in Figure 3.
Installing the Photomask
1. Close the mask frame with the switch at the front of the alignment module.
2. With the chrome side facing down, place the photomask on the mask plate using
the alignment pins to properly locate the mask.
3. Turn the Mask Vac. ON.
4. Place the mask clamps over the photomask and secure.
5. Rotate the mask plate so that the x-axis of the mask corresponds the x-axis of the
microscope's movement. This procedure will greatly facilitate the location of
alignment structures on the mask.
6. Open the mask frame. The substrate may now be placed on the substrate holder
assembly (vacuum chuck.)
Placing the Substrate on the Vacuum Chuck and Alignment
1. Place the substrate on the vacuum chuck using the alignment pins (if provided) to
orient the substrate and turn the Sub. Vac. Switch ON.
2. Close the mask frame.
3. Place the Align Optics over the mask by releasing the vacuum hold and moving it
forward. Using the small X-Y stage for the final alignment. Then focus the
microscope on the mask alignment structure.
4. Using the Z motion knob located on the right front-side of the alignment module,
raise the substrate (by smoothly rotating the Z Knob) until it is in focus but not touching the
mask. (NOTE: Use low magnification for set-up and for locating the alignment structures
because low magnification provides the greatest depth of focus and widest field of view.)