Time resolution and power consumption of a monolithic silicon pixel prototype in SiGe BiCMOS technology

TL;DR

This paper demonstrates that monolithic silicon pixel sensors in SiGe BiCMOS technology can achieve sub-50 ps time resolution with low power consumption, highlighting the impact of amplifier power on timing performance.

Contribution

It provides the first detailed characterization of time resolution and power dependence in SiGe BiCMOS silicon pixel sensors without internal gain.

Findings

Achieved 140 ps time resolution at 7 μA amplifier current

Improved to 45 ps at higher power consumption

Simulation indicates time-over-threshold measurement affects timing accuracy

Abstract

SiGe BiCMOS technology can be used to produce ultra-fast, low-power silicon pixel sensors that provide state-of-the-art time resolution even without an internal gain mechanism. The development of such sensors requires the identification of the main factors that may degrade the timing performance and the characterisation of the dependance of the sensor time resolution on the amplifier power consumption. Measurements with a $ \mathrm{^{90}Sr} $ source of a prototype sensor produced in SG13G2 technology from IHP Microelectronics, shows a time resolution of 140 ps at an amplifier current of 7 $ \mathrm{\mu} $A and 45 ps at higher power consumption. A full simulation shows that the resolution on the measurement of the signal time-over-threshold, used to correct for time walk, is the main factor affecting the timing performance.