Development of Ni₂P Contact Technology and Its Integration on III-V Materials for 300 mm Si Photonics Platform

Flore Boyer,Patrice Gergaud,Christophe Jany,Philippe Rodriguez,Stephane Minoret,Nicolas Coudurier,Romain Famulok

doi:10.1109/jeds.2021.3135971

Abstract

In order to assess their potential use as contact layers for Si photonics devices, Ni 2 P thin films were developed on a 300 mm platform. The Ni 2 P layers, obtained by magnetron sputtering of a Ni 2 P target, were stable and reproducible. The films were mainly composed of the hexagonal Ni 2 P phase with small amount of Ni 12 P 5 impurities. The film density was 6.9 g/cm 3 with a ratio of 62 at.% of Ni and 38 at.% of P. We implemented and integrated these Ni 2 P films on III-V structures to study their electrical properties on n-InP and p-InGaAs (i.e., n-doped and p-doped III-V/Si hybrid laser contact layers). The results obtained on p-InGaAs did not meet the requirements in terms of contact resistivity. On the other hand, due to its high thermal stability and low contact resistivities, Ni 2 P metallization exhibited the best results among the Ni-based metallizations studied for contacting n-InP layers, namely Ni, NiPt and Ni 2 P.

Highlights

T HE interest for Si photonics [1]–[3] grew with the thirst for information and digital data over the past years
The presence of such impurities is inherent to the target fabrication process and its presence was confirmed by X-ray Diffraction (XRD) analyses of the raw powder, the sintering plate and the Ni2P final target
1) Evolution of the Ni2P / InP System With Temperature: In section III-A, we highlighted that Ni2P films were sensitive to air and that a thin oxide layer grew at their surface without any protection

Summary

INTRODUCTION

T HE interest for Si photonics [1]–[3] grew with the thirst for information and digital data over the past years. We propose the development of Ni2P thin films on a 300 mm platform by magnetron sputtering, their physico-chemical characterization and their integration on IIIV layers, n-InP and p-InGaAs in particular, to evaluate their potential in terms of contact layer for Si photonics devices. These results were partially reported in the 20th International Workshop on Junction Technology (IWJT) [35]

EXPERIMENTAL SECTION

RESULTS AND DISCUSSION

Integration of Ni2P Films on III-V Materials

CONCLUSIONS