For users without a CAD drawing of their wafer layout,
the navigate on wafer customized solution offers a multi position measurement workflow.
The solution defines and navigates to various points on the wafer for imaging.
To select the navigate on wafer solution,
use the Materials Solutions workflow in the right tool window.
The image area is synchronized with the live image.
The image toolbar on the left has different options.
Display a scale bar.
Display a crosshair.
Refresh display synchronizes the image area with a live image.
Select the zoom factor for the live image from the list or enter the value.
Fit to window adjusts the zoom to display the whole image.
You can also switch between images using the gallery tool window.
The wafer layout and its alignment are defined using three given chip positions.
The workflow area has options to perform a three point
alignment and to navigate on the wafer.
You have direct access to individual row and column based chip positions,
and the option to define a chip position list with points of interest on a chip.
These points are used for all movements to various chip positions.
Let's define the wafer.
Center one corner of the wafer’s chip.
Set it as the first reference point.
For example, row one column one.
Define the second reference point.
To do so, move the stage to another column
such as ten and click the set two button.
Repeat this procedure for the last reference point.
For instance, row ten, column ten.
In the points of interest definition tab, define your first chip.
For example, chip A at row one, column one.
You can now define as many points of interest on this chip as desired.
Move the stage to a certain position,
select an objective lens and enter a name for this point of interest.
As an option you can use a tilted Z plane correction
or auto focus for each point of interest.
Add further points of interest.
Review your defined points of interest
by selecting the point and double clicking on your chip.
Let's define a second chip, for instance chip B at row 2, column 2.
The three points of interest from chip A are also assigned to the same positions on chip B.
For example, select point two and alternately double click on chip A and B.
In the sample navigation window you can see how the stage moves
between both chips but always stays at the same point per chip.
You can save and load your positions list for every wafer type.
In the image array tab you can choose to acquire snapshots
of the points of interest or acquire stitched images around the points.
You can save the images in different formats
such as TIFF or compromised JPEG files.
Here you can set the compression factor.
Let's start the automatic scan for chip A and B.
Click the start scan button and choose the folder to store the acquired images.
Let's observe the process.
The wafer solution moves the stage to every point of interest
and chip A and B and acquires images accordingly.
At point three, AutoFocus is executed.
Find the images of all points of interest
in chip A and B in two dedicated subfolders.
If you swap the wafer on on the stage with another one,
the new wafer might be misaligned horizontally.
To realign it, define the wafer with a three point alignment procedure again.
You can immediately start a new scan.
For more information on the navigate on wafer customized solution,
visit evidentscientific.com