Development of new 3D pixel sensors for phase 2 upgrades at LHC

We report on the development of new 3D pixel sensors for the Phase 2 Upgrades at the High-Luminosity LHC (HL-LHC). To cope with the requirements of increased pixel granularity (e.g., 50×50 or 25×100 μm
²
pixel size) and extreme radiation hardness (up to a fluence of 2×10
¹⁶
n
eq
cm
⁻²
), thinner 3D sensors (∼100 μm) with electrodes having narrower size (∼ 5 μm) and reduced spacing (∼ 30 μm) are considered. The paper covers TCAD simulations, as well as technological and design aspects relevant to the first batch of these 3D sensors, that is currently being fabricated at FBK on 6″ wafers.