Speaker
Ms
Mar Carulla
(IMB-CNM (CSIC))
Description
This presentation introduces the latest technological development on the Inverse Low Gain
Avalanche Detector (iLGAD). This structure is based on the standard Avalanche Photo Diodes (APD)
concept that includes an internal multiplication of the charge generated by radiation. The
multiplication is inherent to the basic n
++
-p
+
-p structure, where the doping profile of the p
+
layer is
optimized to achieve high field and high impact ionization at the junction. In order to ensure a uniform
electric field distribution along the device, the iLGAD is a pad-like LGAD with P-type multiplication
layer below the N+ implant, in which we change the P+ implantation, by several P-type strips in order
to segment the readout electrode, like a P-on-P microStrip detector. In this structure, we move the
multiplication layer to the back-side of the chip, and define the ohmic readout elements, strips &
pixels, in the front-side, as shown in Figure 1. That means the collecting current is dominated by holes
instead of electrons.
This kind of device with inner amplification allows us to reduce the substrate thickness in order to
develop a low-mass tracking systems with thinner microstrips sensors conserving the same SNR.
iLGAD structures could be interesting for tracking and timing applications, as well as for primary
interaction vertex or medical applications.
In this work we will present the basic technological steps and the last characterization results of the
first iLGAD fabricated at CNM.
Co-author
Ms
Mar Carulla
(IMB-CNM (CSIC))
