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A Comparison of Plasma and Mechanical Dicing of Indium Phosphide / JACK REYNOLDS
Swansea University Author: JACK REYNOLDS
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PDF | E-Thesis – open access
Copyright: the author, Jack Reynolds, 2026. Distributed under the terms of a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).
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Abstract
Compound semiconductor materials such as Indium Phosphide (InP) are widely used in devices such as optoelectronic devices. As these materials and devices become more advanced they become increasingly expensive to fabricate. These high fabrication costs mean that yield has to be high to reduce wasted...
| Published: |
Swansea
2026
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Meredith, P., Burwell, G., and Ritchie, D. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa71904 |
| Abstract: |
Compound semiconductor materials such as Indium Phosphide (InP) are widely used in devices such as optoelectronic devices. As these materials and devices become more advanced they become increasingly expensive to fabricate. These high fabrication costs mean that yield has to be high to reduce wasted material. These demands necessitate the need for a lower defect inducing dicing method as an alternative to conventional saw dicing. This work focuses on developing a novel dicing process for InP using an inductively coupled plasma reactive ion etcher (ICP-RIE). A SiO2 hard mask as well as two photoresist masks SU-8 and polyimide were evaluated under two different plasma chemistries to etch InP. The aim of the work was a >100 µm deep etch to show that plasma dicing is applicable to InP. As the work was focused on dicing a particular focus was placed on achieving a high etch rate and selectivity while still maintaining a vertical anisotropic etch. The concept was first demonstrated on a 15 mm by 15 mm piece using an SU-8 mask with a HBr plasma chemistry, an etch depth of 137.75 ± 9.95 µm was achieved in 60 minutes, corresponding to an average etch rate of 2.30 ± 0.15 µm/min and a selectivity of 20.9:1. Scaling the up the surface area to a 25 mm by 25 mm pieces only reduced the etch rate by 0.32 µm/min, indicating the process can be extended to whole wafer dicing. Post-etch removal of the SU-8 mask was also investigated with P1316 yielding the lowest surface roughness of the removal methods trialled (5.68 nm compared to the original 3.19 nm). Plasma induced defects were assessed and compared with a saw diced sample. Saw dicing exhibited defect regions with reduced recombination efficiency extending from 1 µm at 5 keV to >4 µm at 20 keV on both sides of the trench. In contrast, the average defect region width was 2 µm and 1.28 µm for the HBr and Cl/Ar chemistry respectively. These results have demonstrated that plasma dicing is a applicable process for low defect die singulation of InP. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Indium Phosphide (InP), Plasma dicing, Inductively coupled plasma (ICP), Die singulation, Cathodoluminescence (CL) |
| College: |
Faculty of Science and Engineering |
| Funders: |
KLA Corporation |