Difference between revisions of "Stepper 2 (Autostep 200) - Piece vs. Wafer Programming Differences"

Latest revision as of 14:38, 11 January 2024

In this section you can find instructions how to expose first/second layer on a full wafer and on the wafer piece using a single centered reticle.

Exposing full wafers:

First layer

Follow instructions for job programming. Create the job with passes needed for exposing different layers on the wafer. Select the proper chuck, attach the shim if needed. Load the chuck with a wafer on the stage. Type on the keyboard EX or EXEC Job name\Pass name1. Wait for the stage to stop moving. There is no need for aligning. The pattern will be centered to the center of wafer. This is your first layer. Microscope inspect after developing to make sure exposure looks good.

Second layer

Select the proper chuck, attach the shim if needed, for your wafer. Load the chuck with a wafer on the stage. Edit your job and make sure information for the Job name\Pass name is correct. On the keyboard type command EX or EXEC Job name\Pass name2. Wait for the stage to stop moving. Start manual alignment. Find your right alignment mark on the right monitor, and align cross on the right objective to the right alignment mark. Press "A" and switch to the left objective. Align left objective to the left alignment mark. Repeat process until you are satisfied with alignment. You should see the same amount of the light between lines. Make sure your alignment looks good on the right objective. Press EXEC on the keyboard. Microscope inspect after developing to make sure second layer is aligned well to the first layer.

Exposing wafer pieces:

Exposing wafer pieces is more complicated than wafer substrates. The main reason for this is that wafer pieces are usually small, they are not as flat as wafers are. Resist on a wafer piece is not coated as uniformly as it is on the wafer. The first challenge for wafer pieces is getting the first layer at the right place. This requires some skills regarding loading and aligning the wafer piece, as well as entering correct parameters in the job (key offset, pass shift). Document bellow explains exposing a first layer on the wafer piece if using a single centered mask plate.

1. First layer

Please find detailed instructions how to expose the first layer on a wafer piece using a single centered mask plate.

Single centered mask - Piece 1st lithography Autostep200 *

2. Second layer

Please find detailed instructions how to expose the second layer on a wafer piece substrate using two different mask plates:

Single centered mask plate (for wafer pieces with orientations BL (bottom left), and BR (bottom right):Single centered plate Piece - 2nd Litho Autostep 200 *

Multi layered mask plate (for wafer pieces with either orientation ( BL or BR): Quads mask plate Piece - 2nd litho Autostep 200 *

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+In this section you can find instructions how to expose first/second layer on a full wafer and on the wafer piece using a single centered reticle.
-{{WIP}}
-=='''JOB Programing - FULL'''==
-This section describes how to set up a job to do a step and repeat exposure of your patterns. A more detailed description is given in section 8 of the Autostep 200 Advanced Operation and Utilization (White binder\Biljana's desk).  Jobs are created using the '''SPEC''' command.  First information about the array steps, alignment offsets, and general job is asked for. Passes are attached to each job to apply parameters unique to each pass specified. You can have up to 6 passes in one job. In this way all exposure information for a complete mask set can be specified all in one job.  Following is the procedure for setting up a job and passes.
+====<u>Exposing full wafers:</u>====
-'''Notes:''' If at any point you wish to stop and start over with the job description hit CTRL C followed by A and ENTER on the keyboard to abort the SPEC command.  An abort of this type will result in no saved information.  Also when a * is displayed, this indicates the default value if you hit enter for a reply to a question asked by the computer in setting up or editing any job.  If a numeric value is asked for hitting enter will leave the value previously specified, if that exists.  Also, if you put in an incorrect value and wish to go back a step type “?” and ENTER.
-#At the colon sign type '''SPEC''' “jobname” and hit enter.  The "jobname" can be 1-9 alphanumeric characters long.
-#Select M (metric units)
-#Input a job comment such as “HBT-1 process”
-#Set tolerance to 1
-#Hit Enter for scale
-#Hit enter for orthogonality
-#Leveler Batch Size- input 1 to use wafer leveling, and -1 to turn leveling off.
-#Enter the wafer diameter in mm.  This defines the maximum area in which exposure can occur.  If you have a square or non-circular piece, you will need to specify a diameter that includes the entire square, not the length of a square.
-#Enter the <u>step size</u> in X in mm at the wafer plane
-#Use '''“C”''' for specifying the number of columns to expose and "A" to fill in all area in X direction to the edge of a circular wafer. For square pieces you will always use '''“C”'''.  For quarter wafers, you will most likely use '''“C”''' and make the job array look square. You will then use dropouts in each pass to specify more complicated array shapes.
-#When “C” is entered, you will then be able to enter the number of columns desired.
-#Repeat 9 through 11 for the Y step. The final array is centered on the wafer.
-#Translate Origin is generally used only if the wafer is off-center.
-#If you wish to see an “*” cartoon of the exposure array hit Y for display, otherwise hit Enter.
-#Layout will give you a display of the number of rows and columns and the distance from die (1,1) to the array center, taking origin translation into account. Usually this is not looked at. Hit enter to pass this up.
-#If you wish to adjust the numbers of rows and columns you can do this at the Adjust prompt.  Usually, you can hit enter to skip this.
-#'''Standard Keys''': If you choose '''"Y"''',  then the die used for right and left alignment is chosen automatically by the system.  This is good if you have a wafer larger than 63.5 mm in the X direction and both alignment marks are exactly 63.5 mm apart. If you do not meet these conditions (most jobs do not), you will need to choose '''"N"'''.
-#If '''“N”''' is chosen you will need to enter the row and column of the right alignment die.
-#<u>'''For wafers'''</u>: We usually select right and left alignment die bellow the center of wafer, and on the same row. Most practical is selecting left and right alignment die to be in last row. This also helps to quickly find alignment die, and do alignment.
-#<u>'''For pieces'''</u>: We usually select right and left alignment die to be in the last row.
-'''Right\Left Key Offset''':
+=====First layer=====
-The key offset is distance from the die (mask) center to the alignment mark center on the first layer (or the layer you will be aligning to).  Enter the number in (mm) at the wafer plane.  See picture below for sign convention of an alignment mark placed in quadrant 1 on the mask. The picture assumes normal Cartesian coordinates with the center-lines crossing at (0,0) and the mask is chrome-side down and oriented as it would be on the stepper. (This is the same orientation that you will have when viewing your L Edit file).
+Follow instructions for job programming.  Create the job with passes needed for exposing different layers on the wafer. Select the proper chuck, attach the shim if needed. Load the chuck with a wafer on the stage. Type on the keyboard EX or EXEC Job name\Pass name1. Wait for the stage to stop moving. There is no need for aligning. The pattern will be centered to the center of wafer. This is your first layer. Microscope inspect after developing to make sure exposure looks good.
+=====Second layer=====
-'''Sign Convention for Alignment <u>key offset</u> on Mask''' (main cell)- insert the photo
+Select the proper chuck, attach the shim if needed, for your wafer. Load the chuck with a wafer on the stage. Edit your job and make sure information for the Job name\Pass name is correct. On the keyboard type command EX or EXEC Job name\Pass name2. Wait for the stage to stop moving. Start manual alignment. Find your right alignment mark on the right monitor, and align cross on the right objective to the right alignment mark. Press "A" and switch to the left objective. Align left objective to the left alignment mark. Repeat process until you are satisfied with alignment. You should see the same amount of the light between lines. Make sure your alignment looks good on the right objective. Press EXEC on the keyboard. Microscope inspect after developing to make sure second layer is aligned well to the first layer.
-#If Non-standard alignment keys are selected (most of the time they are, step 18), you will need to select the left and right alignment die. For example if we have 10X10 exposures, this could be for right alignment die (R=10,C=10) and for the left alignment die (R=10,C=1).
-#Left Key Offset  and Right Key Offset are always same. Only for user who have one single exposure (one die), they would need to have left and right key offset different!
-#Skip through epi shift.
+====<u>Exposing wafer pieces:</u>====
-#Now you are ready to enter information specific to passes.
+Exposing wafer pieces is more complicated than wafer substrates. The main reason for this is that wafer pieces are usually small, they are not as flat as wafers are. Resist on a wafer piece is not coated as uniformly as it is on the wafer. The first challenge for wafer pieces is getting the first layer at the right place. This requires some skills regarding loading and aligning the wafer piece, as well as entering correct parameters in the job (key offset, pass shift). Document bellow explains exposing a first layer on the wafer piece if using a single centered mask plate.
-#Enter the name of the first pass.  When you expose a job, you will specify it as '''jobname\passname'''.  The name of a pass can be 1 to 9 alphanumeric characters long.  (i.e. emitter)
-#Next enter a pass comment
-#Enter '''"Y"''' or '''"N"''' for local alignment.
-#If this is <u>'''a first pass'''</u> (there is no any pattern on your wafer), you need to select in here '''"N"'''. Follow instructions to finish writing this pass, and saving.
-#If this is '''<u>a second pass</u>''' or any other pass with critical alignment you should select '''"N"'''. Follow instructions to finish writing this pass, and saving.
-#Aligning a second layer to the first layer (crirtical alignment and you need to use local alignment mark) would require writing a pass ( usually called "mapping pass". In this case you need to select  "'''Y"''' for local alignment. Local alignment mark  ('''DFAS''') needs to  to be on the layer that is being used for aligning.
-#Expose Mapping Pass:  '''Yes''' for (die x die) alignment and exposure.
-#Use two point alignment:  '''Yes''' will check your local alignment marks on your global alignment die and correct for rotation error prior to shooting.
-#Set Rotation Tolerance to '''2microRadians'''
-#Continue with Mapping:  '''Yes''' if mapping should continue after 2-point alignment.
-#Number of alignments per die:  Enter 1
-'''Local Alignment Mark Offset:'''
+=====1. First layer=====
-The local alignment mark offset is '''distance''' from the <u>die (mask) center</u> to the local alignment mark <u>center(DFAS) on the first layer</u> (or the layer you will be aligning to).  Enter the alignment mark position in X, and Y in (mm) at the wafer plane.  See picture above for sign convention of the global alignment mark being placed next to global alignment mark in quadrant 1 on the mask. The picture assumes normal Cartesian coordinates with the center-lines crossing at (0,0) and the mask is chrome-side down and oriented as it would be on the stepper. (This is the same orientation that you will have when viewing your L Edit file).
+Please find detailed instructions how to expose the first layer on a wafer piece using a single centered mask plate.
-#Monitor Mapping Corrections:  Choose "Y" if you want to see data before exposure to make a judgment on whether to continue.
-#Map Every Nth Wafer:  Enter 1 to map every wafer you shoot.
-#Next, input an exposure time between 0 and 128 sec. The calibrations are done at 0.38 sec. for 0.9um SPR 955-CM resist on silicon.  This time should be optimized for your substrate and process before doing the real devices to ensure optimum resolution.  Dose is calibrated for the system each lamp change.
-#33) Expose Calib Factor: 1
-#34) Focus Offset:  Based on a focus calibration that you do, you will have a focus offset from the baseline calibration job.  This calibration is done daily with a mark built-in to the system.  Focus offset is an integer.  +1 = 0.1 microns of lens movement up from the wafer.  -1 = 0.1 microns towards the wafer.
-#35) Microscope focus offset:  Same units as above.  Used so that your wafer will be in focus right away.  You will find out this number the first time you expose.
-#36) Enable Match:  Can use marks on your mask to make sure reticle is exactly aligned.  If you have the marks (standard on Photronix masks), and say yes:
-#a.     Match Template Name:  MATCH
-#b.     Match every Nth Wafer:  Enter 1.
-#c.     Reticle Rotation Offset:  Enter 0.
-#d.     Reticle T: 0
-#37) AWA Parameter File Name:  just press Enter
-#38) Use pass shift to shift all exposures in this pass by a set amount.  Usually this option is passed over, but may be used if you have multiple levels on a single mask and are aperturing all layers but the one of interest and this pattern is off-center.  You would enter the correct offset to ensure pattern alignment. See picture below for sign convention for X and Y for pass shifts to place pattern into center of wafer. Enter the number in mm at the wafer plane.  See picture below for sign convention of pass shift for a pattern placed in quadrant 1. The picture assumes normal Cartesian coordinates with the center lines crossing at 0,0 and the mask is chrome-side down and oriented as it would be on the stepper.
-{| class="wikitable"
-|
-|-
-|
-|
-|}39) Reticle Bar Code:  If you have a bar code on your reticle, enter the value here, otherwise hit enter.
+[https://wiki.nanofab.ucsb.edu/w/images/3/3d/Single_centered_mask-Piece_1st_litho_AUTOSTEP_200.pdf Single centered mask - Piece 1st lithography Autostep200] *
-) Masking Aperture Setting:  You can set the aperture blades independently, entering values between 0 and 97 for the blade movement, in millimeters.  0 is completely open for all blades.  The smallest square you can aperture to is 5mm x 5mm (that means 1mm x 1mm at the wafer plane)
+=====2. Second layer=====
-) Reticle Alignment Offset:  Enter 0 for all these values.
+Please find detailed instructions how to expose the second layer on a wafer piece substrate using two different mask plates:
+*Single centered mask plate (for wafer pieces with orientations BL (bottom left), and BR (bottom right):[https://wiki.nanofab.ucsb.edu/w/images/b/ba/Single_centered_mask-Piece_2nd_litho_AUTOSTEP_200.pdf Single centered plate Piece - 2nd Litho Autostep 200] *
-) Reticle Alignment Phase:  Enter N for negative (clear squares)
+*Multi layered mask plate (for wafer pieces with either orientation ( BL or BR): [https://wiki.nanofab.ucsb.edu/w/images/d/de/4_Quads_mask_plate_Piece_-_2nd_litho_AUTOSTEP_200_%281%29.pdf Quads mask plate Piece - 2nd litho Autostep 200] *
-) Reticle Transmission:  Hit Enter.
-) Array or Plug.  When P is entered, only those row and column sites that the user enters will be exposed.  When A is entered all sites previously specified will be exposed except dropouts specified later.
-) When P is entered, enter the row and column numbers of die you wish to be exposed.  Enter D at the R prompt to display the currently selected die. Press return with a blank entry at the R prompt when finished.
-) In the dropout section, sites or entire rows or columns can be removed from the exposure.  Enter the row.  Then enter at the C prompt: nothing to remove the whole row, the first and last column number with a dash in between (i.e.3-6) to remove several sits, or a single number to remove a single site.  Enter D at the R prompt to view the die that will be exposed.  Enter V at the R prompt to see a list of dropouts. Enter ? at the R prompt to put back in the last die that was dropped out.  Again hit return with no entry at the R prompt to exit.
-) Answer Y to save pass.
-) If no other passes are desired, hit enter with no entry at the name prompt.
-) Enter another pass name if desired and hit enter.
-) If the pass information is mostly the same as a previous pass, hit Y at the Copy prompt and enter the name of the pass to be copied, then change any needed parameters after the job is saved using the EDIT command.
-) Say Y to Write to Disk or all information will be lost.
-) You are ready.
-''Editing an existing job:''
-To edit an existing job, use the EDIT command followed by the file name.  You can then scroll through job and all passes and change any desired parameters.
-Don’t forget to save the changes.  If you just wanted to look at the program you can use the EDIT command and then use CTRL C followed by A and a carriage return to abort the command and not save any changes.
-You can also edit a job by using the JOB command.  You can play with this.  It is menu driven and lets you easily change parameters without having to scroll through an entire program.