10. Other measurement needs

Attention

Unfinished section

10.1. SEAD

Single energy absorption detection

Term coined in a paper by Filipponi et al.

explain INI file, plotting, dossier

10.2. Raster

Single ROI area scans. A map of sorts.

explain INI file, plotting, dossier

10.3. Wafers

There is some functionality specifically for measuring films grown on large, round wafers. The basic experiment involves measuring XAS of 1 or more edges from selected positions on a film. BMM has sample holders specifically designed for holding standard size silica or crystalline wafers.

Most such experiments involve reliable motion to specific locations on the film. This usually starts with finding the center of the wafer and indexing locations relative to the center.

The method for finding the center involves finding the X,Y coordinates of three points around the periphery of the wafer, then using geometry to find the center of the circle intersecting those three points.

RE(wafer.edge())

With the focused beam in the vicinity of a point on the edge of the wafer, make a scan in xafs_x, plotting the signal on I_t, to find the X,Y coordinates of a point in the edge. This method will execute the linescan (Section 8), fit a lineshape to the measurement, then move to the position of the wafer’s edge. This must be repeated three times on three widely spaced points.

wafer.push()

After finding a point using RE(wafer.edge()), push the current X,Y coordinates to a list. After three measurements of the wafer edge, this list will contain the three X,Y coordinates of edge points.

wafer.points

The list containing the three edge points.

wafer.find_center()

Compute the wafer center from the contents of wafer.points.

RE(wafer.goto.center())

Move the xafs_x and xafs_y stages to the center position.

wafer.center

The center position of the wafer.

wafer.clear()

Clear the contents of wafer.points in order to start over.