50 Gb/s Zn-diffusion Few-Mode VCSELs for over 100-m GI-SMF Transmission at 850 nm Wavelength

Purpose – This paper aims to compare the reflow and Zn diffusion behaviors in Sn-Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga (5E) solders during soldering on a Ni/Cu substrate under infrared (IR) reflow. The study proposes a model on the effect of various elements particularly Zn diffusion behavior in the solders on the formation of intermetallic compounds (IMCs). Design/methodology/approach – The melting activities of two solders near their melting points on copper substrates are visualized in an IR reflow furnace. Reflowed solder joints were analyzed using scanning electron microscope and energy dispersive X-ray spectroscopy. Findings – Reflow behaviors of the solders are similar. During melting, solder balls are first merged into each other and then reflow on the substrate from top to bottom. Both solders show a reduced amount of Zn in the solder. Theoretical calculations demonstrate a higher Zn diffusion in the 5E solder; however, the amount of Zn actually observed at the solder/substrate interface is lower than Sn-9Zn solder due to the formation of ZnAg3 in the solder. A thinner IMC layer is formed at the interface in the 5E solder than the Sn-Zn solder. Research limitations/implications – The present work compares the 5E solder only with Sn-Zn solder. Additional research work may be required to compare 5E solder with other solders like Sn-Ag, SnAgCu, etc. to further establish its practical applications. Practical implications – The study ascertains the advantages of 5E solder over Sn-Zn solder for all practical applications. Originality/value – The significance of this paper is the understanding of the relation between reflow behavior of solders and reactivity of different elements in the solder alloys and substrate to form various IMCs and their influence on the formation of IMC layer at solder/substrate interface. Emphasis is provided for the diffusion behavior of Zn during reflow and respective reaction mechanisms.

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Edge Breakdown Suppression of Avalanche Photodiodes using Zn Diffusion and Selective Area Growth

2019 IEEE Photonics Conference (IPC) ◽

10.1109/ipcon.2019.8908476 ◽

2019 ◽

Author(s):

O. Salehzadeh ◽

G. Bonneville ◽

O. J. Pitts ◽

A. J. Spring Thorpe

Keyword(s):

Avalanche Photodiodes ◽

Selective Area Growth ◽

Zn Diffusion ◽

Selective Area ◽

Area Growth

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Diffusion of Zn into Gaas 0.6 P0.4:Te From Zn-Doped Oxide Films By Rapid Thermal Processing

MRS Proceedings ◽

10.1557/proc-92-393 ◽

1987 ◽

Vol 92 ◽

Cited By ~ 6

Author(s):

A. Usami ◽

Y. Tokuda ◽

H. Shiraki ◽

H. Ueda ◽

T. Wada ◽

...

Keyword(s):

Diffusion Coefficient ◽

Thermal Processing ◽

Rapid Thermal Processing ◽

Oxide Films ◽

Zn Diffusion ◽

Enhanced Diffusion ◽

Conventional Furnace ◽

Zn Concentration ◽

The Difference ◽

Doped Oxide

ABSTRACTRapid thermal processing using halogen lamps was applied to the diffusion of Zn into GaAs0.6 P0.4:Te from Zn-doped oxide films. The Zn diffusion coefficient of the rapid thermal diffused (RTD) samples at 800°C for 6 s was about two orders of magnitude higher than that of the conventional furnace diffused samples at 800°C for 60 min. The enhanced diffusion of Zn by RTD may be ascribed to the stress field due to the difference in the thermal expansion coefficient between the doped oxide films and GaAs0.6P0.4 materials, and due to the temperature gradient in GaAs0.6P0 4 materials. The Zn diffusion coefficient at Zn concentration of 1.0 × l018 cm−3 was 3.6 × 10−11, 3.1 × 10−11 and 5.0 × 10−12 cm2 /s for the RTD samples at 950°C for 6 s from Zn-, (Zn,Ga)- and (Zn,P)-doped oxide films, respectively. This suggests that Zn diffusibility was controlled by the P in the doped oxide films.

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