Performance of Silicon Pixels after Radiation Daniela Bortoletto Gino Bolla Amitava Roy Carsten Rott

Irradiation at IUCF We irradiated 5 chips from Sintef wafer 9 (7,39,42,44,46) at Indiana University Cyclotron Facility on 30th November. Pixel 7,44 and 46 are baseline design. Pixel 42 spiral ring and pixel 39 single ring design. Pixel 7,39,42 and 46 were exposed to a fluence of 1x10 14 p/c.m. 2. Pixel 44 were exposed to 6x10 14 p/c.m. 2

Pixel 7 Design A Fluence -1x10 14

Pixel 39 Design B Fluence -1x10 14

Pixel 42 Design D Fluence -1x10 14

Pixel 44 Design A Fluence -6x10 14

Pixel 46 Design A Fluence -1x10 14

What we expected Increase in current  I= .V.  eq (This equation gives the change of current in the plateau region of the IV curve. For these pixels the plateau region is between 50V to 250V)  = 4.0x A/cm 1, V = 0.59x0.49x0.03 cm 3  eq = 1(6)x10 14 cm -2  I = 3.5x10 -5 (21x10 -5 ) A A single pixel x0.015 cm 2 Increase in current through a single pixel  I single pixel =  I x 0.015x0.015/(0.59x0.49) A = 27.2 (163) nA 1 Value of  from Rose Collaboration -

What we got For Pixel 7 I 200V = 2.67x10 -5 A I 300V = 6.94x10 -5 A For Pixel 39 I 200V = 3.11x10 -5 A I 300V = 4.98x10 -5 A For Pixel 42 I 200V = 2.80x10 -5 A I 300V = 5.69x10 -5 A For Pixel 46 I 200V = 2.85x10 -5 A I 300V = 3.90x10 -5 A] For Pixel 44 I 200V = 1.16x10 -4 A I 300V = 2.77x10 -4 A Pixel 44 received 6 times higher fluence than the other pixels. Leakage current of pixel 44 is 4(5) times higher than the other pixels at 200(300)V.