arXiv subjects

Manwen Liu

Publications and source records attributed to Manwen Liu.

4 recordsLinked to original sources

arXiv2026

Development of Small-pitch, Ultra-thin 3D Silicon Sensors at USTC

We report on the development of 3D silicon sensors at the University of Science and Technology of China (USTC). The sensor involves columnar electrodes (5 um in diameter) of both doping types, etched from the same wafer side. The p+ electrodes pass through the epitaxial wafer, whereas the n+ electrodes stop at a short distance from the opposite side of the epitaxial wafer. With respect to previous generations of 3D sensors, they feature an ultra-thin active substrate (50 um) and a small pixel size of 50 um x 50 um or 25 um x 25 um. This R&D project aims to establish a sensor technology to simultaneously measure position and time information at the single-pixel level. The first run with one merged wafer layout has been completed. The design, fabrication, and characterization of the sensors are reported in this paper.

physics.ins-det↗

arXiv2026

Design and Characterization of Racetrack 3D-Trench Silicon Sensor Based on 8-Inch Process with Excellent Time Resolution

In the extreme environments of high-luminosity colliders, traditional planar silicon sensors suffer severe radiation-induced performance degradation and fail to satisfy the stringent demands of high-precision tracking and high-speed timing in particle physics. 3D silicon sensors enhance radiation hardness by shortening charge collection distance, yet conventional designs with columnar or square-cell trench electrodes exhibit non-uniform electric fields, including saddle points and low-field regions, which degrade charge collection efficiency and timing resolution. This work presents a novel racetrack 3D-trench silicon sensor with continuous racetrack electrodes surrounding a long central collection electrode, aiming to eliminate electric field inhomogeneities. For the first time, a 23 $\mu $m shallow-etched device was fabricated on an 8-inch platform, which provides a promising basis for its subsequent mass production and engineering applications. The device performance was systematically evaluated through theoretical analysis, 3D TCAD simulations, and characterization using semiconductor parameter analyzers and transient current technique (TCT) measurements. The sensor achieves leakage current below 0.2 nA, breakdown voltage above 110 V, full depletion voltage as low as a few volts, capacitance as low as 650 fF, collected charge of 4 fC, time response of about 640 ps, and time resolution of 50 ps. This large-scale manufacturable, shallow-etched racetrack 3D-trench silicon sensor provides a competitive device solution for portable radiation detection and next-generation 4D tracking under high-radiation and high-event-rate conditions.

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arXiv2025

Development of 3D Pixel Sensors via an 8-inch CMOS-Compatible Process

In the construction of High-Luminosity Large Hadron Collider (HL-LHC) and Future Circular Collider (FCC) experiments, 3D pixel sensors have become indispensable components due to their superior radiation hardness, fast response, and low power consumption. However, there are still significant challenges in the process of 3D sensors manufacturing. In this work, single devices and arrays of 3D sensors based on 30 $\mu$m epitaxial silicon wafer have been designed, simulated, fabricated, and tested. This process was developed on the 8-inch CMOS process platform of the Institute of Microelectronics of the Chinese Academy of Sciences (IMECAS). The key processes include Deep Reactive Ion Etching (DRIE) with the Bosch process, in-situ doping, and an innovative back-etching. After testing the 3D pixel sensors, we have summarized the leakage current and capacitance of devices with different sizes with respect to bias voltages. We also found that the fabricated devices were almost all successfully produced, which laid a strong foundation for subsequent large-scale mass production.

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arXiv2024

Design, fabrication and initial test of a novel 3D-Trench sensor utilizing 8-inch CMOS compatible technology

The 3D silicon sensor has demonstrated excellent performances (signal collection, detection efficiency, power consumption, etc.) comparable or even better with respect to the traditional planar sensor of the ATLAS Detector at the Large Hadron Collider (LHC), especially after the high irradiation fluence, mainly due to the shorter drift length of the generated carriers. These characteristics have made it the most attractive technology for the detection and track reconstruction of charged particles for the High Energy Physics (HEP). In addition, its application is also being explored in astronomy, microdosimetry and medical imaging. This paper will present the design and fabrication of a novel 3D-Trench sensor which features an enclosed deep trench surrounding the central columnar cathode. This novel sensor has been fabricated on the 8-inch COMS pilot line at the Institute of Microelectronics of the Chinese Academy of Sciences (IMECAS) where ultra-narrow etch width of 0.5 {\mu}m and the ultra-high depth-to-width ratio (aspect ratio) (>70) have been achieved. Its preliminary simulation and characterization results including electrostatic potential, electric field, Current-Voltage (IV), Capacitance-Voltage (CV), Charge Collection Efficiency (CCE) and Timing Performance before irradiation will be presented in this paper.

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