About Alignments

When you put a new sample in your chamber or move to a new sample that’s already in your chamber, you must do an elastic peak alignment. An elastic peak alignment ensures that the distance between the sample and the analyzer (for an Auger elastic peak alignment and SIMS) or the sample and the X-ray source (for XPS) that you’re using is optimal. Part of the process of acquiring an alignment is done manually, while part of it is done using the software.

An alignment is the only acquisition type for which the data is not averaged. Every sweep is a fresh scan of the sample. Therefore, you cannot “continue” an alignment.

AES Alignments

There are two distinct uses of the AES alignment procedure. The first use is the AES elastic peak alignment (for when you put a new sample in your chamber or move to a new sample that’s already in your chamber). The AES elastic peak alignment is the most commonly used type of AES alignment. In fact, AES is the only technique for which an elastic peak can be acquired.

The second reason for acquiring an AES alignment is to monitor the presence of elements on the surface of your sample (for example, carbon). This second use is referred to as simply the “AES alignment routine.” You will perform the AES alignment routine to sweep over a specific energy range to determine the correct multiplier voltage before acquiring a survey, depth profile, or multiplex when you are using an analog multiplier supply (such as the model 20-075).

For an AES Elastic Peak alignment, you align the sample to the focal point of the analyzer by setting the software acquisition parameters in the Alignment Settings dialog box while physically moving the sample until the distance is correct (as indicated by the colored vertical line in the AugerScan document window).

When acquiring data, you must determine if you are using an analog multiplier supply (such as the 20-075) or a digital multiplier supply (such as the 32-100) multiplier supply because this determines the procedures you follow for acquiring data. For example, when you use an analog multiplier supply, you need to acquire the AES alignment routine before performing all acquisition types. When you use a digital multiplier supply you will use the AES elastic peak alignment routine while you will seldom use the AES alignment routine. The procedures for acquiring the data will guide you through these details.

You can differentiate AES alignments during acquisition to get a better picture of the peak characteristics. To do this, select the Differentiate command after the alignment is started. To revert back to peak N(E) data, select the Revert to Raw command.

XPS Alignments

For XPS, do an AES elastic peak alignment first, then use an XPS alignment to optimize signal by moving the X-ray source position.

SIMS Alignments

Before you acquire a SIMS alignment, you must first acquire an AES elastic peak alignment. Even though you may not acquire AES data, the elastic peak alignment ensures that the ion gun is properly aligned with respect to the sample. Remember that SIMS is a destructive technique so that the sample is changing as you sputter it away. Typically, you will do a SIMS alignment on the edge of your sample and then simply move the stage’s X axis to the area of the sample that you want to acquire. (If you are moving only the X-axis, you do not need to acquire another AES alignment. Or, you can do an alignment on one sample, then move to another sample, do an AES alignment, and acquire your data.) When you are acquiring a SIMS alignment, you may change the Acceleration voltage, Retard voltage, Ion voltage, and Focus voltage settings in real time. This lets you see the effect that changes to these settings have on the data that is acquired.

Additionally, a SIMS Positional Alignment can also be used for optimizing your SIMS acquisitions. Click here for more information.

To get information on acquiring alignments for a specific technique, click on one of the items below:

AES Elastic Peak Alignments

XPS Alignments

SIMS Alignments