SCS 6808P Spinner
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iLab Name: Spinner2
iLab Kiosk: BRK Lithography Core
FIC: David Janes
Owner: Joon Park
Location: Cleanroom - M Bay
Maximum Wafer Size: 6"/150 mm
Overview
General Description
The Specialty Coating System 6800 is a programmable spin coating system to apply a liquid coating (i.e. photoresist) to a planar substrate. Multistep spin recipes with independent acceleration/deceleration, spin speed, and spin duration may be programmed quickly through the controller. The machine is a single chuck unit that requires manually loading and unloading substrates. A microprocessor controls recipes as well as operation of the unit.
Specifications
- Program storage: 3 programs, up to 8 steps each
- Maximum substrate size: 6" (bowl limited)
- Speed: 0 - 9,999 RPM (maximum of 8000 RPM recommended) in 1 RPM increments with ± 1 to 3 RPM accuracy.
- Acceleration/Deceleration time: 0.1 - 30 s in 0.1 s step with ± 0.05 s accuracy.
- Dwell (spin time) per step: 0 - 999 s in 1.0 s increments with ± 0.05 s accuracy.
Sample Requirements and Preparation
For the spinner itself, the only cleanliness requirement is that the backside is clean (and free of photoresist). However, cleanliness is very important for the further processing that the sample will experience.
Samples should at least be cleaned with the standard solvent clean, and Piranha cleaning may be used for substrates that will tolerate it. Adhesion of the photoresist will depend on the surface state of the wafer, and a clean, dehydrated, hydrophobic surface will offer ideal adhesion.
Standard Operating Procedure
Training hand-out
New version of SOP for 6800
Potentially useful excerpts from the 6800 Manual:
- "The 6800 Spin Coater Series is a family of compact spin coaters for low production spin coating applications and experimentation. The 6800 Spin Coater Series provides the ability to hold a product with a vacuum chuck and spin that chuck at precise speeds and for controlled periods of time. Operations are extremely repeatable and are settable to 0.1 second. The chuck is indexed back to its initial position at the end of each cycle, so that each wafer may be oriented the same way on the chuck. See the Specifications Section for more information."
- "Operation of the spin coater is controlled by a user friendly keypad. During a cycle, the spinning speed and remaining time are displayed on a user interface screen. The acceleration and deceleration rates are calculated by the controller to provide various ramp profiles. A recipe contains cycle information such as speed, ramp up time, ramp down time, and dwell time at speed."
- "For safety reasons, the machine will shut off if the lid is removed."
- "Remember that the unit will not run unless programmed, and that the lid must be opened and closed before each cycle (indicating that material has been placed in the spin coater)."
- Vacuum chuck selection:1: Chuck diameter ≤ 1" (25 mm).
"Chuck selection should be based on object size and rigidity. The proper chuck diameter is 1/4 to 1 inch (0.6 to 2.5cm) smaller than an object’s diameter. The entire object should be supported if it is flexible, fragile, or if it is to be wiped or brushed during cleaning. Centering is done manually; use templates and measurements for further assistance when centering. Use Step 0 in a recipe to set the chuck size. Designate the chuck size appropriately:"
2: Chuck diameter ≤ 2" (50 mm) and ≥ 1" (25 mm).
4: Chuck diameter ≤ 4" (100 mm) and ≥ 2" (50 mm).
6: Chuck diameter ≤ 6" (150 mm) and ≥ 4" (100 mm). - Step Zero: "Step 0 is the step that tells the spin coater how large the vacuum chuck is. Enter the size in the Disp blank by selecting the number that (most nearly) represents the diameter of the chuck.
- Homing: "to stop the chuck from returning to the Home position at the end of the run, set the step 0 Time to some number other than 0."
- Pause steps: "Pauses at zero RPM can be programmed into the middle of a recipe."
- Extra long periods: "Long periods of the same function can be accomplished using multiple steps."
The 6800 Spin Coater has the following controls:
Dsp_Type: This sets the dispense type. This is also used to set the chuck size in Step 0 only. The following dispense type options are available:
- 1, 2, 4, or 6. Note: For use with Step 0 only. Set the chuck size appropriately.
- Edge
- Solv
- N2
- Coat
- None
- Press ENTER on the Run screen.
- Control Panel
Questions & Troubleshooting
Why has the spinner stopped/failed to spin? (ERR: Lid Open and ERR: Vacuum)
Unit has 2 interlocks that can halt operation. They include Loss of Vacuum and Lid Open faults. Loss of vacuum has several possible causes: 1) Poor placement of chuck. Chucks must be fully pressed to the top of the chuck shaft for proper seal and good vacuum. 2) There is resist clogging vacuum hole in the chuck. Remove the o'ring from the shaft hole in the back of the chuck. Clean the hole out with acetone. Clean the o'ring with IPA and put back into the shaft hole. 3) There is debris on the face of chuck or the back side of your sample. Clean the chuck with acetone. Re-clean your sample or try a different sample. 4) The vacuum path through the motor shaft is clogged. Contact the staff to correct the problem. The lid is also interlocked to insure that it is closed during spinning. Verify that both the lid is fully closed and the chuck is fully seated to the top of the shaft for proper operation.
What is the purpose of Step 0?
Step 0 allows the user to set the size of vacuum chuck used, and disable the homing step at the end of the run. Normally step 0 should be left cleared if the user does not want to utilize either of these functions, as it will not execute a spin step if it is attempted.
Setting the chuck size will give the spinner an estimate for the amount of force needed to accomplish the programmed ramps and speeds. This is important for avoiding unwanted changes in acceleration, and especially important for larger chucks/substrates as they posses substantial momentum. The chuck size is indicated in Step 0 by setting the Disp value to 1, 2, 4, or 6:
1: Chuck diameter ≤ 1" (25 mm).
2: Chuck diameter ≤ 2" (50 mm) and ≥ 1" (25 mm).
4: Chuck diameter ≤ 4" (100 mm) and ≥ 2" (50 mm).
6: Chuck diameter ≤ 6" (150 mm) and ≥ 4" (100 mm).
Setting the Disp Time to a nonzero value will skip the "Homing" step at the end of the run, which will save time if orientation is not important.
Why do I need to close the lid during use?
The spinner goes up to ~10,000 RPM, and accepts a 6" wafer. In this condition, the edge speed of the wafer reaches 180 meters per second. Should the wafer chuck lose vacuum (which is not an uncommon occurance) or the wafer not be entirely secure in a non-vacuum chuck (common, due to wear and tear on the chuck edges), the resulting broken pieces are traveling fast enough to seriously injure you, anyone else working in the hood, and bystanders in the line of the debris.
Why is a "Motion Error" being displayed?
A motion error may be due to a motor issue, but can also be caused by inadequate ramp times. The error will be displayed if momentum is too great to adequately stop/start nearly instantaneously. For example, motion errors may be caused by going from a stop to a 4000 RPM step with a Ramp of 0, or going from a 4000 RPM step to a stop with 0 ramp on the next step. Typical ramp speeds are 1000 rpm/s or 2000 rpm/s, with the ramp time depending on the initial/final RPM (E.g. going from 0 to 4000 RPM at 2000 RPM/s gives a ramp time of 2.0 s).
What is the function of the Disp setting?
Disp is short for "dispense". As our systems lack an automated PR dispenser, this should be set to "None" for all steps except step 0. For Step 0, the numerical choices for Disp will set the chuck size, see "What is the purpose of Step 0?" for an explanation.
Why is there a "ERR: Lid Open" error even though the lid is closed?
The lid switch may, over time, get caught on foil and creep slightly. Try turning off the machine in the back and turning it back on, the error will clear if it is a small deviation. If the error persists, contact BNC Staff to manually adjust the switch.
Process Library
See Process Library on Spin Coating technology page.
NOTE: Spinners are controlled with specific recipes. The controller holds 30 recipes in storage for use. Users need to verify that their spin recipe is correct for their application. Press mode button once to enter edit mode. Cursor will be present on top row to indicate edit mode. Press left/right arrow keys to move to the parameter that requires change and press the up/down arrows to increase or decrease the parameter amount. Press enter to save changes in that step before moving to another step. Press the mode button again to exit edit mode and enter run mode.