MIT/Lincoln Labs CCID20 W53C2 CCD Test Results

This is a high resistivity, thinned, backside MIT/Lincoln Labs 2Kx4K CCD. It is very similar to other high resistivity CCID20s tested at Lick.

A summary report is available. Noteworthy points about this CCD include:

CTE. Near perfect CTE is achieved using the serial and parallel clocks which generate low spurious charge. This is typical of Lincoln CCDs.

Original postscript files are available from our anonymous ftp server and these provide better resolution and clarity than is usually possible on a web page. There are also additional postscript files showing CTE measurements, fringing, and the brick-wall pattern. Check the INDEX file for a description of what the other files contain. Here are a few figures to illustrate device highlights:

QE curve: This is a pretty typical QE curve for the high resistivity CCID20s. Good red response is achieved by the 40 µm thick epi.
CTE: Near perfect CTE is achieved by the Lincoln CCD design.
Surface plot: Hasn't been measured yet.
Long Dark: This 1000s dark was obtained at -127°C.

This plot shows the QE measurements made at about -125°C.

Graph of QE.

The Lincoln CCID20 design produces excellent charge transfer efficiency. This plot shows a test of serial CTE using Fe⁵⁵ xrays.

This plot shows the parallel CTE measurement.

No surface contour images yet...

The data for this curve was obtained by taking a flat field image at each of the indicated temperatures and measuring the amplitude of the quantum efficiency variations. The percents shown are derived by taking a single row cut through the image and computing a percentage as (MAX-MIN)/MEAN. Obviously this emphasizes maximum variations and different results will be obtained if a different row is selected. But the general trend is clear: To reduce the amplitude of the brick wall QE variations, operate the CCD at the highest practical temperature.

This image shows low level features in a 1000s dark. Note that the brickwall pattern is not apparent, unlike some of the standard epi CCDs. In addition to the low-level bright columns there are also a few faint horizontal lines. These may be crystal dislocations in the high resistivity silicon.

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