|
1
|
Wei W, Peng Y, Wang J, Farooq Saleem M, Wang W, Li L, Wang Y, Sun W. Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD. NANOMATERIALS 2021; 11:nano11030698. [PMID: 33802171 PMCID: PMC7999848 DOI: 10.3390/nano11030698] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 11/16/2022]
Abstract
AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80-300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.
Collapse
Affiliation(s)
- Wenwang Wei
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Yi Peng
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Jiabin Wang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Muhammad Farooq Saleem
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Wen Wang
- Advanced Micro-Fabrication Equipment Inc., Shanghai 201201, China;
| | - Lei Li
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Yukun Wang
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
| | - Wenhong Sun
- Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; (W.W.); (Y.P.); (J.W.); (M.F.S.); (L.L.); (Y.W.)
- Guangxi Key Laboratory of Processing for Non-Ferrous Metallic and Featured Materials, Guangxi University, Nanning 530004, China
- Correspondence:
| |
Collapse
|
|
2
|
Status of Growth of Group III-Nitride Heterostructures for Deep Ultraviolet Light-Emitting Diodes. CRYSTALS 2017. [DOI: 10.3390/cryst7100300] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|