Speaker
Mr
Andrew Clarke
(e2v centre for electronic imaging)
Description
The primary aim of ESAs’ Euclid mission is to map the distribution of galaxies and galaxy clusters, with an aim to mapping the ‘dark’ architecture of the universe. This requires a highly accurate CCD, which is also designed to endure a harsh radiation environment.
The e2v CCD204 image sensor was redesigned for use on the Euclid mission; the resulting e2v CCD273 device has, among other changes, a smaller register electrode causing a reduction in the size of charge packets stored, this reduces the number of traps encountered by the signal electrons and therefore improves the serial CTI under irradiation.
The Euclid CCD device structure has been modelled using the Silvaco TCAD software to test preliminary calculations for the full-well capacity (FWC) of the device and provide indications of the volume occupied by varying signal sizes. These results are useful for realising mission objectives and for radiation damage studies.
The FWC of a buried channel (BC) CCD is the total amount of charge which can be stored before ‘blooming’ occurs (i.e. the spreading of charge along the transfer columns into adjacent pixels) or before charge comes into contact with the Si-SiO2 surface interface, causing a reduction of CTE. Devices are preferentially operated at voltages where charge would spill across the transfer columns before contact is made with the surface.
The Silvaco simulations have been tested against actual devices to compare experimental measurements to those predicted in the models. Using these results, the implications of this study on the Euclid mission can be investigated in more detail.
Preferred medium (Oral/poster)
Oral
Author
Mr
Andrew Clarke
(e2v centre for electronic imaging)
Co-authors
Prof.
David Burt
(e2v)
Dr
David Hall
(e2v centre for Electronic Imaging)
Prof.
Holland Andrew
(e2v Centre for Electronic Imaging)
