摘要
8 mil×10 mil InGaN/GaN blue LEDs with indium tin oxide（ITO） emitting at 460 nm were fabricated. A vacuum evaporation technique was adopted to deposit ITO on P-GaN with thickness of 240 nm.The electrical and optical properties of ITO films on P-GaN wafers,as well as rapid thermal annealing（RTA） effects at different temperatures（100 to 550℃） were analyzed and compared.It was found that resistivity of 450℃RTA was as low as 1.19×10^（-4）Ω·cm,along with a high transparency of 94.17%at 460 nm.AES analysis indicated the variation of oxygen content after 450℃annealing,and ITO contact resistance showed a minimized value of 3.9×10^（-3）Ω·cm^2.With 20 mA current injection,it was found that forward voltage and output power were 3.14 V and 12.57 mW.Furthermore,maximum luminous flux of 0.49 lm of ITO RTA at 550℃was measured,which is the consequence of a higher transparency.
8 mil×10 mil InGaN/GaN blue LEDs with indium tin oxide（ITO） emitting at 460 nm were fabricated. A vacuum evaporation technique was adopted to deposit ITO on P-GaN with thickness of 240 nm.The electrical and optical properties of ITO films on P-GaN wafers,as well as rapid thermal annealing（RTA） effects at different temperatures（100 to 550℃） were analyzed and compared.It was found that resistivity of 450℃RTA was as low as 1.19×10^（-4）Ω·cm,along with a high transparency of 94.17%at 460 nm.AES analysis indicated the variation of oxygen content after 450℃annealing,and ITO contact resistance showed a minimized value of 3.9×10^（-3）Ω·cm^2.With 20 mA current injection,it was found that forward voltage and output power were 3.14 V and 12.57 mW.Furthermore,maximum luminous flux of 0.49 lm of ITO RTA at 550℃was measured,which is the consequence of a higher transparency.
基金
supported by the National High Technology Research and Development Program of China(No.2009AA03A 1A3)
the National Key Technologies R&D Program of China(No.2011BAE01B14)
