Low Ohmic Contact Resistance 980 nm VCSELs Fabricated
980nm垂直腔面发射激光器低欧姆接触电阻制备(英文)

980 nm vertical cavity surface emitting laser (VCSEL) ohmic contact technology is investigated. In order to enhance the output power of VCSEL, and extend its reliability, the contact resistance has to be reduced. Ti/Pt/Au alloy is chosen as the metal contact system for P type high doped GaAs, and Ge/Au/Ni/Au alloy is chosen as the metal contact system for N type GaAs. By chosing the optimum alloying temperature of 440 ℃ , the lowest ohmic contact resistance of 0.04Ω is obtained. Comparing output power and conversion efficiency of the device for 440 ℃ and the device for 450℃, the test results show that, the ohmic contact resistance is 0.04Ω, the peak wavelength is 980.1 nm, the FWHM of spectral is 0.8 nm, the lateral divergence angle θ‖ is as low as 15.2°, the vertical divergence angle θ⊥ is as low as 13.5°, the output power is 1.4 W, the maximum conversion efficiency is 14.4% for the device of 440 ℃ , while the ohmic contact resistance is 0.049 Ω, the output power is 1.3 W, the conversion efficiency is 12.8% for the device of 450 ℃ . By optimizing the alloy temperature can effectively reduce ohmic contact resistance of VCSEL 980 nm.