Embed Size (px)
Citation preview
AlN – From amorphous to preferentially oriented hexagonal
thin filmsZ. Chen, M. Bosund, I. Tuoriniemi, V. Malinen, Z. Zhu, E. Salmi, and K. Härkönen
ALD 201818th International Conference on Atomic Layer Deposition
July 29–August 1, 2018 • Incheon, South Korea
Outline
• ALD AlN with three different processes– Plasma enhanced ALD
• TMA – NH3 plasma
– Thermal ALD
• TMA – NH3
• AlCl3 – NH3
• Conclusions
8/20/2018© Beneq 2016 2
TMA–NH3 plasma - Processing
• Single wafer processing with TFS-200– TMA – NH3 plasma
– 220 °C
– 200mm/8’’ wafer
• Thickness uniformity 3.3%
=𝑚𝑎𝑥−𝑚𝑖𝑛
2×𝑎𝑣𝑒𝑟𝑎𝑔𝑒× 100%
• Refractive index 1.875
– Amorphous structure
8/20/2018© Beneq 2016 3
TMA–NH3 plasma – Composition
8/20/2018© Beneq 2016 4
TMA–NH3 – Processing
• Batch processing in P400 reactor
– TMA – NH3
– 350 – 475 °C
8/20/2018© Beneq 2016 5
360mm
240mm
25 shelves
8/20/2018© Beneq 2016 6
TMA–NH3 – Uniformity
TMA–NH3 – Composition
8/20/2018© Beneq 2016 7
350 °C
TMA–NH3 – Composition
8/20/2018© Beneq 2016 8
350 °C 350 °C
TMA–NH3 – Crystallinity
8/20/2018© Beneq 2016 9
AlCl3–NH3 – Processing
• Batch processing in P400 reactor– AlCl3 – NH3
– 500 – 550 °C
8/20/2018© Beneq 2016 10
9 shelves
360mm
240mm
8/20/2018© Beneq 2016 11
AlCl3–NH3 – Uniformity
AlCl3–NH3 – Morphology
8/20/2018© Beneq 2016 12
Rq=1.7 nm Rq=1.0 nm Rq=1.3 nm
500°C 525°C 550°C
AlCl3–NH3 – Composition
8/20/2018© Beneq 2016 13
525 °C
AlCl3–NH3 – Composition
8/20/2018© Beneq 2016 14
AlCl3–NH3 – Crystallinity
15
Conclusions
• AlN growth with varying crystallinity was shown
– PEALD TMA-NH3 plasma resulted in amorphous films
– Thermal TMA-NH3 and AlCl3-NH3 resulted in polycrystalline films with differing orientations
• Thermal ALD processes enabled batch processing with good uniformity
– TMA-NH3 could be processed with up to 25 shelf configuration
– AlCl3-NH3 batch processing clearly improved with increasing deposition temperature
8/20/2018© Beneq 2016 16
