Details
| Original language | English |
|---|---|
| Pages (from-to) | 204-212 |
| Number of pages | 9 |
| Journal | CARBON |
| Volume | 202 |
| Publication status | Published - Jan 2023 |
| Externally published | Yes |
Abstract
The quality of polycrystalline diamond films is heavily dependent on the nucleation and early stages of growth, making the ability to monitor these early stages highly desirable. Spectroscopic ellipsometry (SE) allows for real-time monitoring of the thickness, composition, and morphology of films with sub-nanometre precision. In this work, ex-situ SE spectra were used to develop an optical model for film characterisation, which was then applied to in-situ data. The coalescence of individual crystallites into a single film was observed through a parabolic decrease in void content followed by peaks in sp 2 content and surface roughness. These observations were validated using ex-situ Raman spectra and AFM images of samples grown for durations between 5 and 30 min. The model was also used to investigate the impact of varying the methane concentration, finding that a higher methane fraction resulted in earlier coalescence and a higher peak in sp 2 content. This work demonstrates that SE is a powerful tool for monitoring and optimisation of the critical early stages of polycrystalline diamond growth.
Keywords
- CVD Diamond, Characterisation, Diamond films, In-situ monitoring, Spectroscopic ellipsometry
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
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In: CARBON, Vol. 202, 01.2023, p. 204-212.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - In-situ monitoring of microwave plasma-enhanced chemical vapour deposition diamond growth on silicon using spectroscopic ellipsometry
AU - Leigh, William G.S.
AU - Thomas, Evan L.H.
AU - Cuenca, Jerome A.
AU - Mandal, Soumen
AU - Williams, Oliver A.
N1 - Publisher Copyright: © 2022 The Authors
PY - 2023/1
Y1 - 2023/1
N2 - The quality of polycrystalline diamond films is heavily dependent on the nucleation and early stages of growth, making the ability to monitor these early stages highly desirable. Spectroscopic ellipsometry (SE) allows for real-time monitoring of the thickness, composition, and morphology of films with sub-nanometre precision. In this work, ex-situ SE spectra were used to develop an optical model for film characterisation, which was then applied to in-situ data. The coalescence of individual crystallites into a single film was observed through a parabolic decrease in void content followed by peaks in sp 2 content and surface roughness. These observations were validated using ex-situ Raman spectra and AFM images of samples grown for durations between 5 and 30 min. The model was also used to investigate the impact of varying the methane concentration, finding that a higher methane fraction resulted in earlier coalescence and a higher peak in sp 2 content. This work demonstrates that SE is a powerful tool for monitoring and optimisation of the critical early stages of polycrystalline diamond growth.
AB - The quality of polycrystalline diamond films is heavily dependent on the nucleation and early stages of growth, making the ability to monitor these early stages highly desirable. Spectroscopic ellipsometry (SE) allows for real-time monitoring of the thickness, composition, and morphology of films with sub-nanometre precision. In this work, ex-situ SE spectra were used to develop an optical model for film characterisation, which was then applied to in-situ data. The coalescence of individual crystallites into a single film was observed through a parabolic decrease in void content followed by peaks in sp 2 content and surface roughness. These observations were validated using ex-situ Raman spectra and AFM images of samples grown for durations between 5 and 30 min. The model was also used to investigate the impact of varying the methane concentration, finding that a higher methane fraction resulted in earlier coalescence and a higher peak in sp 2 content. This work demonstrates that SE is a powerful tool for monitoring and optimisation of the critical early stages of polycrystalline diamond growth.
KW - CVD Diamond
KW - Characterisation
KW - Diamond films
KW - In-situ monitoring
KW - Spectroscopic ellipsometry
UR - http://www.scopus.com/inward/record.url?scp=85141283128&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2022.10.049
DO - 10.1016/j.carbon.2022.10.049
M3 - Article
VL - 202
SP - 204
EP - 212
JO - CARBON
JF - CARBON
SN - 0008-6223
ER -