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iLab Name: Spinner1
iLab Kiosk: BRK Lithography Core
FIC: David Janes
Owner: Joon Park
Location: Cleanroom - N Bay
Maximum Wafer Size: 6"/150 mm (with bowl, 8"/200 mm with bowl removed)

STANDARD OPERATING PROCEDURE

This instruction covers the set-up and use of the G3P-8 spinners for coating photo resist samples in the Nuaire Solvent hoods in Bays M and N within the cleanroom.

Table of Contents

1. Safety Requirements                                                                                                                 
2. Equipment                                                                                                                               
3. Facilities & Specifications                                                                                                         
4. Machine Configuration                                                                                                              
5. Cycle of Operations                                                                                                                   
6. Programming
7. Troubleshooting                                                                                                                        
8. Recipes                                                                                                                                    
9. Revision Record                                                                                                                       

1.    SAFETY REQUIREMENTS

       Standard cleanroom safety information:

       Safety glasses must be worn whenever in the cleanroom, except when using a microscope or when wearing protective goggles.

       Information regarding the hazardous materials used in the cleanroom can be found through MSDS documentation located in the gowning room.

       When handling hazardous liquids and chemicals, Personal Protective Equipment must be worn. Protective goggles and solvent gloves must be worn while working in fume hoods.

      G3P-8 Spinners Specific safety information:

      The G3P-8 spinners are relatively harmless machines relating to the operator, apart from the obvious hazards as handling of substrate materials with loading and unloading and dispensing

      photoresist materials to substrates contained in a solvent fume hood. Safety interlocks will stop the spinner with loss of vacuum to the substrate or an open lid condition.

2.    EQUIPMENT

       G3P-8 Spincoat           Specialty Coating Systems, Inc.

       NU-S121-830               Nuaire

                                            M Bay serial # - 101516092305

                                            N Bay serial # - 101285091305

3.    FACILITIES & SPECIFICATIONS

       Facilities:

       Electricity           115 V           300 VA

       Vacuum:             House         17-25” Hg

       Nitrogen:            House          .55 cfm @ 2-5 psi

       Specifications:   Weight          38 pounds

                                 Dimensions   11.8” H X 12.0” D X 16.5” D 

 4.    MACHINE CONFIGURATION

        Units are placed in the cleanroom solvent hoods in lithography bays M and N. Spinner 1 is located in the bay N while spinner 2 is located in bay M. They are single chuck units that require manually loading and unloading of substrates

        A microprocessor controls recipes as well as operation of the unit.

5.    CYCLE OF OPERATIONS

       1)    Reserve tool in iLab for the time slot that you require.

       2)    Enable your tool in iLab.

       3)    Use appropriate PPE while using Fume Hoods. Spinners require the use of goggles.

       4)    Remove bowl and fashion a bowl liner out of supplied aluminum foil. Remove foil over the chuck shaft access.

       5)    Select the proper sized chuck for your substrate. Inspect delrin shaft sleeve and location of a black 8mm O-ring that seals the top of the spinner shaft to the chuck for proper vacuum.

       6)    Place cleanroom wipes around spinner to catch drips and splatter.

       7)    Chuck installation

1. 1. Select appropriate sized chuck. It should be smaller than your sample.
   2. Inspect that vacuum hole is free of resist.
   3. Line up the shaft flat with the flat in the delrin shaft sleeve bushing.

       8)    Program recipe and test with sample in place prior to applying resist.

       9)    Apply resist to sample. Be careful that resist does not get below bowl or on the shaft. Do not over apply resist.

       10)  After you have completed spinning your samples, carefully remove foil and discard.  If you drip resist, clean it up. This includes the hood, walls, controller, trash cans and floor.

       11)  Do’s

1. 1. Clean up after yourself.
   2. Contact staff immediately with function issues.
   3. Pipettes go into sharps container, bulbs go in trash.

       12)  Don’t

1. 1. Leave a mess
   2. Try to alter the system. If you get an error, contact staff.                  (No foil on lid switch).
   3. Spray Acetone on chuck or shaft while chuck is installed in spinner.

6.    PROGRAMMING

             6.1    RECIPE EXAMPLE

             6.2   EXPLANATION OF RECIPE EXAMPLE

             6.3   CONTROL PANEL

             6.4   PROGRAMMING A RECIPE

             6.5   SELECTING A PROGRAM TO RUN

             6.6   RUNNING A RECIPE

             6.7  PROGRAMMING HINTS AND TRICKS    

With the G3P programmable spin coater, you can enter multiple recipes and program it to do complex operations.

 6.1   RECIPE EXAMPLE

         Great flexibility is available in the recipes. The figure above shows RPM versus time for a recipe that demonstrates some of the different actions.

• • The length of a step is shown across the bottom with an arrow.  (Step 1 is 18 seconds, total.)
  • Vertical lines and a number (total seconds) mark each event (start or stop of any ramp, dispense, or dwell).
  • The numbers at the left show the speeds (RPM) used in this recipe.
  • Boxes across the top illustrate the recipe entries for the seven steps

           Note some of the special capabilities accomplished by the recipe:

• • Long periods of the same function can be accomplished using multiple steps (Steps 3 & 4).
  • Sudden speed changes are accomplished by setting Ramp time to zero or a very low number (Step 5). The actual time required is a function of the size of speed change and the amount of weight being spun.
  • Pauses at zero RPM can be programmed into the middle of a recipe (Step 5).
  • Dispensing (option):  Our spinners do not have this option.  Ramps to different speeds and employing different Accel/Decel rates can be combined (Steps 6 & 7).

6.2 Explanation of RECIPE EXAMPLE

          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.  

          Step 1 begins with a Ramp1-- 8 seconds up to an RPM1 of 2000.  Dwell1 is set to keep the speed at 2000 for 10 seconds.  This is a time when you can dispense your photoresist.

                     The dwell continues until its 10 seconds is up.

          Step 2 begins at 18 seconds.  It has no Ramp2 time and also has the same speed (2000 RPM) so it appears to be a continuation of step 1.  Its Dwell2 is set to 10 seconds (combined with step 1

                      this gives a total dwell of 20 seconds at 2000 RPM.

          Step 3 begins at 28 seconds on the figure, and has a 15-second Ramp3 down to an RPM3 of 1400. The Dwell3 is set to 0 seconds. NOTE that this is half of a 30-second ramp down to 800.

                      Since a 30 second long ramp is not possible, the programmer used two 15-second ramps.

          Step 4 is the continuation of the ramp down.  The Ramp4 is 15, and the RPM4 is 800.

          Step 5 tries to cause an instant stop, followed by 4 seconds without any spinning. The Ramp5 is 0, and the RPM5 is 0. The Dwell5 is set to 4 seconds.

                      If the motor can stop quickly enough, the cycle will continue—if the momentum is too great and the motor cannot stop quickly   enough, there will be a “Motion Error:"

                      To avoid the motion error, set Ramp5 to allow a short amount of time for the ramp down.

          Steps 6 & 7: consist of two ramps with no dwell time. RPM6 simply goes up to 2000 in the Ramp6 time of 3 seconds and RPM7 takes it back down to 0 in the Ramp7 time of 3 seconds.

                                If necessary, the Ramp could be set to longer times, to avoid the motion error.

6.3   CONTROL PANEL

           Buttons

• MODE: There are only 2 modes, and this pushbutton moves the controller between the Program/Edit mode and the Run mode. Each time you press it, you change to the other mode.

      In the Run mode, the following spin coater controls are active:

• START: This pushbutton starts a cycle, if all conditions are correct. (For example, the G3P must be in the run mode, and the vacuum sensor must be satisfied, and it may be necessary to open and close the load lid.)
• CLR-ERROR:  If the machine is in the error mode, it will not reset or run. This pushbutton clears (resets) a machine error so that the MODE and START buttons become active again.
• STOP: This pushbutton will stop rotation even if the G3P is in mid-cycle. NOTE: If the chuck and wafer have unusually great momentum, a Motion Error may occur and the electronic breaking may fail; the chuck will coast to a halt. Do not open the lid until you are sure the rotation has stopped completely.

      In the Program/Edit mode, the following G3P controls are active. You are able to enter new recipes and modify the settings of existing recipes.

• ENTER: This pushbutton "enters" (stores) the data you just entered and advances the cursor to the next control block. It is important to press ENTER in order to make sure the data is stored. (Without ENTER, the data is ignored.)

• ← and → (“Navigation"): These arrows can move the cursor to the next/previous data block.
•  ↑ and ↓  (“Set Values"): The G3P has arrows that cause the control variables (seconds or RPM) to increase or decrease. (Press and hold to get bigger changes – the counter will speed up.)

6.4   PROGRAMMING A RECIPE

In the Program/Edit mode you can make and save up to 30 recipes, and program up to 20 steps into each recipe. A step consists of setting up to five variables (Ramp, RPM, Dwell, Disp, and Time).` 

1. Enter the Program/Edit mode by pressing the MODE button. A pointer ( < ) will appear in the display, next to Recipe (see above).
2. Select any recipe number to edit its variables or create a new recipe from scratch. Use the ↑  and ↓ to select a recipe number, then press ENTER.  The recipe number will be entered and the pointer will move to “Step”.

                        NOTE: To remove all the old programming from a recipe, select the recipe number and press CLR/ERROR, then press ENTER.]

      3. 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, and then press enter.

          This is important so that the spin coater give the right amount of force to accomplish the desired ramps and speeds.

      4.  As mentioned previously each step contains 5 variables (or commands), that you use to program the spin coater - Ramp, RPM, Dwell, Disp, & Time. The steps are executed in order from 1 to 20; If you don't

           need all 20 steps, place the pointer at Step and select the step number to be removed; then press CLR/ERROR and then ENTER. Check to see that there are no more steps after that.

         4.1  The step number will increase normally as you program, and won't require changing;

                You accept the step # by pressing ENTER and the pointer will move to “Ramp”.  

                If you wish to modify any step, you can simply use the á and â to move to the desired

                step, and then move with the ß and à to any item within that step and change it. 

                Again, always press ENTER to make sure the changes are actually stored.

         4.2  Ramp: (0 to 25.5 seconds) This number tells the spin coater how many seconds it should take to accelerate or decelerate to the new speed (RPM).  When the pointer is at “Ramp”, use the á and  â to set the time in seconds.

                Then press ENTER and the number will be stored and the pointer will move to RPM. 

                    NOTE:   If Ramp is set to zero, the spin coater will try to comply; but if the required change of speed

                    is too great, a Motion Error may occur

        4.3  RPM: (0 to 9999 RPM) This is the rotational speed for the spin coater for this step.  When the pointer is at RPM, set the speed by using the ↑ and ↓.   Press ENTER and the number will be stored and the pointer will move to “Dwell”.

       4.4  Dwell: (0 to 999 seconds) This is how long to spin at the RPM you just selected.  When the pointer is at Dwell, set the time by using the ↑ and  ↓. Press ENTER and the number will be stored and the pointer will move to “Disp”.

      4.5  Disp:  Our spinners do not have this option, so the option named “None” should always be chosen.  Press ENTER and the pointer will move to “Time”.

      4.6  Time: (0 to 10 seconds) This setting determines how long the Disp. function will be turned on.

             Since  “Disp” is set to "None," then the Time setting should be at 0.      

      5.  After entering all of the steps for your recipe, use the following steps to exit properly:

              5.1  If there are any leftover steps at the end with actions/numbers in them, you must remove them.

                     Move to the unwanted step, and with the pointer at “Step”, press CLR/ERROR to clear it, and press ENTER.

                     Use the ↑ and  ↓ to examine the next steps and clear them if necessary.  Be sure to press ENTER to store the changes or they will be lost.

               5.2  Press MODE to return to operation, or select another recipe to edit/create (using ← and →   & ↑ and  ↓).

6.5   SELECTING A PROGRAM TO RUN

         After the spin coater has completed its startup cycle, you can press START and it will attempt to run whatever recipe is shown on its display.  If there is no recipe, you must enter/select one.

         To select a different recipe, press MODE, change the recipe number, press ENTER, and then exit the Program/Edit mode by pressing MODE again.

                NOTE: The first step shown is numbered "0" and called Step Zero. It is used to tell the spin coater what size vacuum chuck is being used (enter the diameter in inches in the step 0 Disp blank).

                            This is important for the control mechanism, always use the chuck that matches the size called for in the recipe. If different size chucks are used, you can make recipes for each size of chuck.

6.6    RUNNING A RECIPE

1. Make sure you are in the Run mode and the proper recipe is selected (select recipe in the Recipe/Edit mode).
2. Make sure you have the proper size chuck–corresponding to the size called for in the Disp blank of Step Zero.
3. Place the wafer on the vacuum chuck (wafer must be centered for proper operation).
4. Close lid. Do not open the lid during a cycle; the cycle will be terminated and there is potential for injury.
5. Go to the Run mode, and press START to begin a cycle (see the picture on the previous page)
6. During the cycle, the display will show the Recipe number, and the approximate RPM and time remaining.

      7. At the end of each cycle, the vacuum chuck will slowly rotate to the "Home" position (unless programmed to not Home in the Step 0 programming). The display will say REMOVE COATED PARTS.

      8. Open the lid, remove the coated part, and place the next part on the chuck. NOTE: After each cycle, the spin coater lid must be opened and closed before the next cycle will run. This helps avoid spinning the same wafer twice by accident.

      9. You can stop rotation at any time by pressing STOP (in some instances the inertia of the rotating chuck can overpower the motor brake and cause a "Motion Error").

           A "Short Cycle" error will occur if the lid is opened or the STOP button is pressed during a cycle.

      10. The CLR ERROR button will reset the machine if an error occurs.  Pressing Start begins at the start of the current recipe.

      11. If process is to be repeated, go to step 1.

6.7    PROGRAMMING HINTS AND TRICKS

Note the following hints to make it easier and faster to enter a recipe. 

1. To remove an entire recipe:  Place the pointer at Recipe and select the desired recipe number; press CLR/ERROR and then ENTER. All steps will be removed. 
2. To remove a step from the MIDDLE of a recipe: (e.g., you discover you have entered a step twice, and want to remove the extra without moving all the rest of the steps)
   Set all of the variables to zero except the RPM; set that to be the same as the preceding step. Press ENTER.
3. To edit or modify a step's variables:  Go to those particular variables by using the ENTER or the ← and →  and then change the variable by using the the ↑ and ↓. REMEMBER to press ENTER
   afterwards, or the change will not be kept.
4. To extend the ramp function beyond its normal time limit: Use two similar steps. e.g., 1000 to 2000 RPM over 40 seconds, ramp from 1000 to 1500 over 20 seconds in the first step
   (and set Dwell to zero); then ramp from 1500 to 2000 over 20 seconds in the next step.
5. Remember that you must press ENTER to accept any step's programming. If you move about using the navigation arrows ← and →  , your changes are not entered and saved.
   If you change a setting, be sure to press ENTER next.  (An ENTER at any time saves all previous changes that were made during that step.)
6. In step 0 is the ability to turn off the automatic homing after each run (thus saving some time). Set the Time blank to some number larger than 0 to disable homing.

7.   TROUBLESHOOTING

       Unit has 2 interlocks that can halt operation. They include Loss of Vacuum and Lid Open faults. Loss of vacuum is usually due to poor placement of chuck. Chucks must be fully pressed to the top of the chuck shaft for proper seal and good vacuum.

       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.         

8.    RECIPES          

       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.

       Typical recipe

       Step 0   after substrate loaded to chuck, start step

       Step 1   timed ramp and dwell at process rpm

       Step 2   timed ramp down to zero rpm / unload

9.    REVISION RECORD

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

New version

Previous version

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 occurrence) 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.

How can I clear an entire recipe?
With the pointer on the Recipe selection at the desired recipe number, press the CLR/ERROR button, and then the ENTER key. All steps of the selected recipe will be cleared.

How can I delete a step within a recipe?
If the step occurs at the end of a recipe, place the pointer on Step and the step number to be deleted, then press CLR/ERROR and then ENTER. This will only work if the selected step is the last step with nonzero values in the recipe.

If the step occurs in the middle of a recipe, set the RPM to be the same as the preceeding step, set all of the remaining values to be 0, and then press ENTER.

Process Library

See Process Library on Spin Coating techonology page.

NOTE: Spinners are controlled with specific recipes. The G3P-8 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.

References

SCS G3 Spincoat and Multi-Dispense Systems Brochure

SCS G3P-8 User Manual (Internal Resource)

Spinner - Staff (Restricted)