A Near-Infrared CMOS Silicon Avalanche Photodetector with Ultra-Low Temperature Coefficient of Breakdown Voltage.

Daoqun Liu,Bo Tang,Tingting Li,Manwen Liu,Zhihua Li,Peng Zhang,Wenwu Wang

doi:10.3390/mi13010047

Abstract

Silicon avalanche photodetector (APD) plays a very important role in near-infrared light detection due to its linear controllable gain and attractive manufacturing cost. In this paper, a silicon APD with punch-through structure is designed and fabricated by standard 0.5 μm complementary metal oxide semiconductor (CMOS) technology. The proposed structure eliminates the requirements for wafer-thinning and the double-side metallization process by most commercial Si APD products. The fabricated device shows very low level dark current of several tens Picoamperes and ultra-high multiplication gain of ~4600 at near-infrared wavelength. The ultra-low extracted temperature coefficient of the breakdown voltage is 0.077 V/K. The high performance provides a promising solution for near-infrared weak light detection.

Highlights

The following requirements for avalanche photodetector (APD) should be satisfied to enable the capability of weak light detection in light detection and ranging (LiDAR) systems [4]
The electrical field inside photons absorbing region and carrier multiplication region is controlled by the doping profile of the charge layer, which is the key to the Si APD design
Limited by the existing test equipment, the spectral response, the response speed, and the multiplication noise are not able to be presented in this paper

Summary

Introduction

Avalanche photodetectors (APDs) have been widely used for weak light detection due to their large internal avalanche gain. Ge/Si APD [2,12] and APDs based on III-V semiconductor materials [13,14] with ultralow temperature dependency of the breakdown voltage have been demonstrated. These APDs have much higher multiplication excess noise than that of Si APDs due to the lower k-value (the ratio of ionization coefficient of holes over electrons) of silicon. A high-performance Si APD with lower temperature coefficient of 0.32 V/K was demonstrated [8], the wafer thinning process and the double-sided metallization required by such devices are not available for.

Device Design and Fabrication

Dark Current and Photocurrent

Terminal Capacitance

Responsivity and Gain

Conclusions