Further Characterization of the JadePix-3 CMOS Pixel Sensor for the CEPC Vertex Detector: in Dependence of Substrate Reverse Bias

TL;DR

This study thoroughly characterizes the JadePix-3 CMOS pixel sensor for the CEPC vertex detector, focusing on how substrate reverse bias affects its charge collection, efficiency, and noise performance, confirming its suitability for high-precision tracking.

Contribution

It provides the first detailed analysis of substrate reverse bias effects on JadePix-3's performance metrics, guiding future sensor development for collider experiments.

Findings

Reverse bias improves charge collection efficiency.

Sensor operates reliably with reduced fake-hit rate.

Depletion region expansion enhances detection performance.

Abstract

The Circular Electron-Positron Collider (CEPC), a proposed next-generation $e^+e^-$ collider to enable high-precision studies of the Higgs boson and potential new physics, imposes rigorous demands on detector technologies, particularly the vertex detector. JadePix-3 is a prototype Monolithic Active Pixel Sensor (MAPS) designed for the CEPC vertex detector. This paper presents a detailed laboratory-based characterization of the JadePix-3 sensor, focusing on the previously under-explored effects of substrate reverse bias voltage on key performance metrics: charge collection efficiency, average cluster size, and hit efficiency of laser. Systematic testing demonstrated that JadePix-3 operates reliably under reverse bias, exhibiting a reduced input capacitance, an expanded depletion region, enhanced charge collection efficiency, and a lower fake-hit rate. These findings confirm the sensor's potential for high-precision particle tracking and vertexing at the CEPC while offering valuable references for future iterational R\&D of the JadePix series.