Short manual for KLA Tencor Profiler

This short-form manual is NOT sufficient to learn how to use the profiler.
You MUST receive teaching from a responsible person before using the profiler the first time!

How to remove the back-scan (backwards movement) before scanning

How to export data to text.

This web-manual is more of a memory support when returning to the profiler after some time.

The profiler is completely computer-controlled via a series of screens (or layouts).

The first thing you should do is to power on the computer screen.
The last thing you should do is to power OFF the computer screen, to save it.

Never exit the control program since it is very slow to start again, many initializations of the profiler.

A breif listing of the different screens would include:

These screens are here listed in a functional order, which is not neccessary the order you will find the screens when you work with the profiler.

Usually the first screen you see when powering on the screen is the one below.


This is where you load your sample, position it and usually start scanning a profile. The round object to the right is a picture of the circular sample holder, and the black dot is representing the position of the profiler sensing tip.

The area to the left, with the tic-marked coordinate system, is also containing a microscope image of the sample. The length of the central blue arrow indicates the scan-length set in the current recipe. At start you do not see much because the scan head is lifted away up from the sample holder and nothing is in focus.

 


Here are the buttons at the top.
In order to place your sample you first press button MAN LOAD
The sample holder will move to the foremost position, you open the front window, and place your sample EXACTLY at the center of the circular sample holder. It has some holes symetrically placed, the center hole is easily recognized, cover that hole with your sample.

 


Here the sample holder is in the LOAD position, closest to the front loading-door. The sample, a small Si-chip, is positioned at the center.

 


A close-up of the chip. Note that it is placed at the center of the drilled holes in the sample holder.

Close the front window.

Press MAN LOAD again, the sample holder will move to the center.

Press FOCUS, this will happen:

Now you can move around on your sample to position the profile you want to scan. The SLOW, MED and FAST buttons decide how much you move per click on the arrow buttons.


Point and click at some point in the image and this point will be moved to the center of the image. Please not that this only works if the image is fully ZOOMED OUT. Use the ZOOM OUT button to set this.

If you point and drag in the image you will define the center position and the scan length at the same time. The blue arrow will be set to the length you define.

If you press and hold down one of the arrow buttons, the sample stage will move faster, and not do a back-lash compensation for each step. Back-lash compensation looks like a fast back-and-forth movement at the end of each step.

Position your sample so that the blue arrow falls across the profile you want to scan.

If you want to modify the current recipe, or select another recipe, click the Close window button at the upper, right corner. This will take you to the screen below.


If you want to select another recipe close this window also using the Close window in the upper right corner. This will take you to the Recipe select screen.

There are many parameters to modify in a recipe, below are the most important described.

 


The length of the profile, either choose from the list or type in the value, in micrometers.

 


The scan speed, depends on type of sample, how big and abrupt the surface height changes are. Too slow scan speed makes the scanning unneccessary time consuming.
Too short makes the profile erronenous, with overshoots at abrupt step-changes and features missed due to sensing tip not able to trace the surface correctly.

 


Sampling rate, how often a height value is collected from the sensor. Depends on the structure of the sample, fine structure requires higher sample rates at constant scan speed. Higher scan speeds require higher sampling rate to keep the resolution constant.

 


Multi-Scan average: same profile is scanned sveral times and an average in each sample point is computed. Good for average out random noise from environment. Usually not necessary in our lab.
Note the values computed in the Scan Time: area, Individual Trace is the time for one profile in seconds, they are all depending on the X Scan Size, Scan Speed and Sampling Rate in the following way: 
            Individual Trace = X Scan Size / Scan Speed
           Total Data Points = Sampling Rate / Scan Speed × X Scan Size
              Point Interval = Scan Speed / Sampling Rate

 


Applied force: the force with which the sensor tip is pressing against the sample. Can make the tip follow the sample better at higher scan speeds.
May damage the tip if used excessively. May also scratch the sample if surface is soft enough. For resist thickness measurements it is usually sufficient with 0.2 or 0.5 mg.

 


Range/Resolution: If you know roughly how large height variations there are on your sample you can set this parameter accordingly. The Range value means the total amount of height variation that is acceptable during the scan before saturation of the height sensor. If the sample has an overall slant this will affect the setting.

 


Profile type: What you expect the sample to be like: For smallest Range / highest resolution only the first alternative is available.

Start the scan

When all parameters of the recipe is set to your liking, move to the Load / Teach Scan Length screen by pressing the button. You will now have the screen below.

Make sure your are at the right position to start the scan, then press the START button. The microscope image will switch to sideways view of the tip and the scan will start.

 


To the right the profile will grow as the scan is collected. The profile is slanted since the sample always has some overall slant.

 


Here is a full-resolution image of the "Live scan area". If the scan-line slants outside of the top or bottom of the diagram it is auto-scaled to contain the profile. This works up to the maximum Range/Resolution parameter set earlier in the recipe.

 

When the scan is finished the screen is automatically changed to Analysis.


Here the collected profile is displayed with perhaps a rough levelling.

 


When the Analysis screen is shown first, it defaults to Measurement cursors being active. First thing to do is to properly level the profile. Activate the Levelling cursors by pressing the button.

 


Now the two Level cursors are active, just below top frame of the Scan Data window. The cursors can be moved by the track ball and clicking/pressing the left button. As you see the cursors has a width in which the mean height value is computed and used for levelling.
The levelling is performed by placing the two cursor mean values on the same level.

I find it easier to move the cursors with the keyboard arrow buttons:

When the two cursors are satisfactory positioned, in this case at the far left, and just before the raising slope, the button is pressed again, and the levelling is carried out.

 


Now the step height can be measured by placing the Meas cursors in correct positions. They are manipulated in the same way as the levelling cursors. You can read the step height to the left in the Cursors area, in this case St height: 143.6 Å.

 

Recipe selection


To get to this Recipe Selection Catalog screen, you have to close the Recipe Editor with the usual close button at the top right corner. Then you will come to this screen.

 


Each user has their own folder to store recipes. Select one and click the View/Modify button to check or change parameters of the recipe. There are also some standard recipes in the top level folder which can act as starting points for recipes.

 


The buttons at the bottom of this screen can START the scan immediately if you have already set the start position is correctly. The XY View button will switch to the screen with microscope image and positioning buttons. The other buttons I assume are self-explanatroy.

 

Here are the buttons to change working mode of the profiler.
Configuration mode, which is not available to the ordinary user.
Calibration mode which should be used carefully by knowledgable users only!
Scan mode, ordinary Profiler mode, the mode described here.
Export and import of profile data, recipes etc. Useful to export profiles into other programs.
Stress mode, measure curvature of wafer due to stress from thin film depostion (not covered here).
 
 

Anders Liljeborg
Nanostructure Physics
KTH