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Gonçalez Filho W, Borga M, Geens K, Cingu D, Chatterjee U, Banerjee S, Vohra A, Han H, Minj A, Hahn H, Marx M, Fahle D, Bakeroot B, Decoutere S. Development and analysis of thick GaN drift layers on 200 mm CTE-matched substrate for vertical device processing. Sci Rep 2023; 13:15931. [PMID: 37741914 PMCID: PMC10517926 DOI: 10.1038/s41598-023-42747-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023] Open
Abstract
This work reports the epitaxial growth of 8.5 µm-thick GaN layers on 200 mm engineered substrates with a polycrystalline AlN core (QST by QROMIS) for CMOS compatible processing of vertical GaN power devices. The epitaxial stack contains a 5 [Formula: see text]m thick drift layers with a Si doping density of 2 × 1016 cm-3 and total threading dislocation density of 4 × 108 cm-2. The thick drift layer requires fine-tuning of the epitaxial growth conditions to keep wafer bow under control and to avoid the formation of surface defects. Diode test structures processed with this epitaxial stack achieved hard breakdown voltages > 750 V, which is shown to be limited by impurity or metal diffusion from the contact metal stack into threading dislocations. Conductive Atomic Force Microscopy (cAFM) reveals some leakage contribution from mixed type dislocations, which have their core structure identified as the double 5/6 atom configuration by scanning transmission electron microscopy images. Modelling of the leakage conduction mechanism with one-dimensional hopping conduction shows good agreement with the experimental data, and the resulting fitting parameters are compared to similar findings on silicon substrates. The outcome of this work is important to understand the possibilities and limitations of vertical GaN devices fabricated on large diameter wafers.
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Affiliation(s)
- Walter Gonçalez Filho
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium.
- CMST-IMEC, Ghent University, Technologiepark 126, 9052, Ghent, Belgium.
| | - Matteo Borga
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Karen Geens
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Deepthi Cingu
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Urmimala Chatterjee
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Sourish Banerjee
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Anurag Vohra
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Han Han
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Albert Minj
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
| | - Herwig Hahn
- Aixtron SE, Dornkaulstr. 2, 52134, Herzogenrath, Germany
| | - Matthias Marx
- Aixtron SE, Dornkaulstr. 2, 52134, Herzogenrath, Germany
| | - Dirk Fahle
- Aixtron SE, Dornkaulstr. 2, 52134, Herzogenrath, Germany
| | - Benoit Bakeroot
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
- CMST-IMEC, Ghent University, Technologiepark 126, 9052, Ghent, Belgium
| | - Stefaan Decoutere
- IMEC-Interuniversity Microelectronics Center, Kapeldreef 75, 3001, Leuven, Belgium
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