Self-compensation effect in Si-doped Al sub(0.55) Ga sub(0.45) N layers for deep ultraviolet applications

• Published in: Japanese Journal of Applied Physics Vol. 54; no. 5
• Main Authors: Pyeon, Jaedo, Kim, Jinwan, Jeon, Minhwan, Ko, Kwangse, Shin, Eunyoung, Nam, Okhyun
• Format: Journal Article
• Language: English
• Published: 01-05-2015
• Subjects: Compressive properties; Constants; Flow rate; Hall effect; Photoluminescence; Silicon; Strain; Ultraviolet
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.54.051002

The self-compensation effect in Si-doped Al sub(0.55) Ga sub(0.45) N layers was investigated using different SiH sub(4)/III ratios. The degree of compressive strain changed with SiH sub(4) flow rate during growth. With a low SiH sub(4)/III ratio of 2.46 x 10 super(?6), compressive strain was increased in comparison with the un-doped case. However, above this SiH sub(4)/III ratio, compressive strain decreased from ? sub()xx ?5.07 x 10 super(?3) to 4.28 x 10 super(?3) when the ratio was increased to 4.1 x 10 super(?5). For higher SiH sub(4)/III ratios, the compressive strain again increased, which is attributed to the self-compensation effect of Si atoms. A similar tendency was observed in Photo-luminescence (PL) results. While the UV-to-violet ratio (I sub(UV)/I sub(VL)) of room-temperature PL remained to be almost constant for SiH sub(4)/III ratios below 8.2 x 10 super(?5), I sub(UV)/I sub(VL) decreased rapidly above this value, as a result of self-compensation of Si atoms. These results were in good agreement with the Hall effect measurements.