Physical modeling and analysis of a full-custom, standard-CMOS process photodetector

NICOLÁS CALARCO; FÉLIX PALUMBO; SEBASTIÁN PAZOS; FERNANDO PEREZ QUINTIÁN

Virtual

Conferencia; Conferencia Argentina de Electrónica; 2021

In this work, the complete physical modeling of a full-custom photodetector, made of a concentric photodiode array implemented in a standard CMOS process, is presented. Front-end-of-line for the target technology is replicated based on electrical measurements and the general structure for the photodiode array is built based on the circuit layout. The structure is fully parameterized into Sentaurus TCAD command files, for a versatile migration to different technology vendors or processes. Simulations show good agreement in terms of photoresponsivity with the fabricated IC. As one of the main issues in detector arrays, crosstalk simulations are performed showing relative charge sharing values as high as 30% between neighboring pixels on the proposed design. Results show that, even with little detail regarding process proprietary information, physical modeling proves a valuable optimization tool for IC designers in the photonics domain. Command files for structure generation and simulation are made available via a public repository, open to the design and physical modeling community.