3D pixel sensors aimed at the upgrades of the ATLAS and CMS experiments at the High Luminosity LHC have small pixel size and pretty dense layouts. In addition, modified 3D designs with small pixel size and trenched electrodes in place of columnar electrodes are being developed to optimize the pixel timing performance in view of the LHCb upgrade. The fabrication of these advanced 3D pixels is challenging from the lithographical point of view. This motivated the use of stepper lithography at Fondazione Bruno Kessler in place of a standard mask aligner. The small minimum feature size and high alignment accuracy of stepper allow a good definition of the sensor geometries also in the most critical layouts, so that a higher fabrication yield can be obtained. In this paper, we will present the main design and technological issues and discuss their impact on the electrical characteristics of 3D pixel sensors of different geometries.

旨在升级高亮度LHC的ATLAS和CMS实验的3D像素传感器具有较小的像素尺寸和相当密集的布局。此外，鉴于LHCb升级，正在开发具有较小像素尺寸和沟槽电极代替柱状电极的改进型3D设计，以优化像素时序性能。从光刻的角度来看，这些高级3D像素的制造具有挑战性。这激励了在Fondazione Bruno Kessler中使用步进光刻来代替标准掩模对准仪。最小的最小特征尺寸和较高的步进对准精度可在最关键的布局中很好地定义传感器的几何形状，从而可获得更高的制造良率。在本文中，