Operating Procedure

SOP 1: Select Objective

The system should have been left in the Home Position. Verify this before choosing objective.

Select your working objective and internal magnification. If you are unsure, make your best guess where to start based on what you hope to learn about the sample.

The objectives selector

There are 4 objectives and 3 internal magnifications giving us 12 different combinations of FOV and Optical Resolution.

screen shot to show Objective Selection
Objective Selection on the Measure Tab
Mx™ Software Screenshot

Changing the objective requires the user to raise the instrument up before selecting the new objective (which rotates the turret).

Failing to do so could cause significant damage to the lenses and scanner.

There is a warning reminder on the side of the monitor.

The refered-to warning label on the side of the monitor.
Raise objectives to create enough space for safe turret rotation warning reminder on monitor.
PSU MCL

SOP 2: Load the Sample

It is very important when loading the sample to pay attention and not touch any of the objectives on the turret. Doing so can damage the instrument, and it most definitely will mess up the current calibration on the entire turret.

Feel free to navigate the X,Y of the stage to create more room for loading.

Never stick your fingers under the objectives to try and manipulate your sample; move the sample out, make your adjustments and then move it back under with the motors.

Sample in place under the objectives
Pay careful attention when loading sample. It is not okay for users to make contact with any part of the turret.
Zygo

SOP 3: Set the Z-Stop (CRITICAL)

Setting the Z-Stop is broken up into three parts:

Part I. Fast approach.

The goal of this part is to take a good chunk of the Z travel out of the way. Set the Z motor speed to fast, press the Z-Stop button until it is blinking red, and come down until the objective/sample distance is about 1 inch (~25mm).

Shows the motor speed and z-stop buttons
Set motor speed to FAST and Press Z-Stop till blinking red.
Lower the objective to ~1 inch (25mm) from the surface of the sample.
Keep an eye on the gap; keep an eye on the other objectives.

Part II. Medium approach.

The goal of this part is to SLOW DOWN and get the objective working distance below the surface of the sample being measured. Set the Z-motor speed to medium; leave the Z-stop blinking red.

Shows the Z-motor speed at medium and the red, blinking Z-stop button
Set the Z-motor speed to MEDIUM, leave Z-Stop blinking red.
Lower the objective until the working distance of the lens is lower than the sample surface.
Keep an eye on the gap; keep an eye on the other objectives.

Part III. Set the Z-Stop.

The solid red Z-stop button
Press Z-Stop once so it is now solid red.

SOP 4: Move to Focus Position

The instrument is now protected from driving the stage down further than where the Z-stop has been set. The user and the software are prevented from moving below the Z-Stop.

Focus Aid graphic
From the measure tab, go to Focus Aid.

Please watch the following Focus Aid video (:26).

  • Move up in Z in MEDIUM speed until the bright spot is centered in the bull's-eye.
  • Slow down (with the twist motor control) as you get close to center and attempt to get the fringes visible.
  • The brightness of the spot is dependent on the sample. The rougher and more scattering the sample, the more dim this spot will be. It is possible not to have one. In that case, go back to normal view and attempt to focus on the sample surface by eye.

SOP 5: Adjust the Light Level

Please watch the following (:15) video: "Set the Light Level."

  • Close the Focus Aid.
  • Center the fringes in the view window, making sure the brightest fringe is in the center.
The Auto LL button
Adjust the light level by pressing the Auto LL button or F9.

 

SOP 6: Null the Pitch and Roll

If there are clear fringes (as in this example) or if there is clear X/Y directional trends as the scanner is moved in Z, it is possible to null the pitch and roll.

The Auto Tilt button
Press Auto Tilt. The instrument will move through Z and track the stage tilt correction needed.
The Auto Tilt button
Press Auto Focus. The instrument will move through Z and attempt to put the fringes centered in the focus of the field of view. This may require small adjustments in Z by the user when completed to move the center (brightest) fringe into the field of view.
Demonstrating Auto Tilt and Auto Focus
The Auto Focus/Tilt button
Do not use Auto Focus/Tilt; it performs the operations in the wrong order. Better to separate them into first Auto Tilt then Auto Focus as done above.

 

SOP 7: Set Measurement Setup Parameters

Go to the Measurement Setup Section

Screenshot of the Measurement Setup panel
Measurement Setup
Mx Software Screenshot

The objective is already chosen. If this needs to be changed, move up in Z, rotate to desired FoV, go back to SOP 1, and start over from the beginning.

Work through Measurement Type, Measure Mode, Z Resolution, Subtract System Reference, Scan Length, Scan Origin, Averages, Signal Oversampling, High Dynamic Range options to set up the scan.

If unsure on an option, pick one and look at the results.

SOP 8: Measure

Please watch the Measurement Setup and Scan video (:56).

After going through the Measurement Setup Parameters:

Enter image and alt text here. No sizes!
Press Measure or F12 to start a scan.

 

SOP 9: Adjust Scan Parameters as Needed

At the completion of the scan, check the result in the top right result window of the Measurement Tab.

Enter image and alt text here. No sizes!
Check results of the scan in the top right results window when measurement is complete.
Mx Software Screenshot

A good scan will have the most NPoints possible for that surface. The total possible NPoints would be every pixel of the camera getting a result which is 1024x1024, or 1,048,576. Not every surface is capable of getting full pixels for the image; the rougher the surface, the more dropped pixels. The only good reason for dropping pixels are near vertical surfaces (since this is a reflection based technique, it cannot collect data from a vertical feature).

If there is large areas of missing data, scan again to try and determine where the Measurement Setup Parameters could be improved.

SOP 10: Home the Instrument when Finished

Since this is a multiuser based instrument, we want to be respectful of all the users that come into the lab. Part of this would be leaving the area neat and tidy for the next user; each user is responsible for their mess. Part of this would be leaving the stage in a safe position while not in use. Every user is asked to leave the instrument the same way.

When finished, while your data is copying to your X-Drive or box.psu.edu drive, please Home the stage.

Screen capture to show the Motion Utilities box
Go to Motion -> Utilities
Screen capture to show the Motion Utilities box
Choose Home All Axes.
The X, Y, Z, P, and R will all reset.
Screen capture to show the correct Z-stop setting
Set the Z-Stop at the Homed Z position, locking the scanner at its maximum height till the next user is ready to begin.