On the Role of AlN Insertion Layer in Stress Control of GaN on 150-mm Si (111) Substrate

• Published in: Crystals (Basel) Vol. 7; no. 5; p. 134
• Main Authors: Lin, Po-Jung, Tien, Ching-Ho, Wang, Tzu-Yu, Chen, Che-Lin, Ou, Sin-Liang, Chung, Bu-Chin, Wuu, Dong-Sing
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 12.05.2017
• Subjects: Aluminum nitride; Chemical vapor deposition; Compressive properties; Curvature; Decomposition; Discontinuity; Insertion; Mathematical analysis; Metalorganic chemical vapor deposition; Silicon substrates; Stability; Switching; Tensile stress
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst7050134

In this study, low-temperature (LT) and high-temperature (HT) AlN insertion layers (ILs) grown at 680 and 970 °C were integrated with 3.7-μm GaN-based heterostructure grown on 150-mm Si (111) substrates by metalorganic chemical vapor deposition. Under a V/III flow ratio of 1960, the GaN epilayer with a continuous interface resulting from the LT AlN IL was subject to a compressive stress of −0.109 GPa. However, the GaN epilayer with discontinuous interfaces resulting from the HT AlN IL growth under the same flow ratio was subject to a tensile stress of 0.174 GPa. To realize continuous interfaces between the GaN epilayer and HT AlN IL, a higher V/III ratio of 5960 was utilized to suppress the decomposition of GaN. It results in changing the stress state of the GaN-based heterostructure from tensile to compressive. This strategic finding indicates that a stress-controllable GaN on Si can be achieved via the incorporation of HT AlN ILs. A minimum curvature at 5 km−1 is demonstrated for the 3.7-μm GaN-based heterostructure on a 150-mm Si (111) substrate, which has high potential for power switching device applications.