Effect of Pt Interlayer on Low Resistivity Ohmic Contact to p-InP Layer and Its Optimization
Lili Han1,2,3, Chunhua Du1,3,5, Ziguang Ma1,3, Yang Jiang1,3, Kanglin Xiong6, Wenxin Wang1,3,4, Hong Chen1,3,4, Zhen Deng1,3,5*, and Haiqiang Jia1,3,4*
1Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3Center of Materials and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China 4Songshan Lake Materials Laboratory, Dongguan 523808, China 5The Yangtze River Delta Physics Research Center, Liyang 213000, China 6NANO-X, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
Abstract：The contact characteristic between p-InP and metal plays an important role in InP-related optoelectronic and microelectronic device applications. We investigate the low-resistance Au/Pt/Ni and Au/Ni ohmic contacts to p-InP based on the solid phase regrowth principle. The lowest specific contact resistivity of Au(100 nm)/Pt(115 nm)/Ni (50 nm) can reach $2.64 \times 10^{-6}\,\Omega \cdot$cm$^{2}$ after annealing at 380 ℃ for 1 min, while the contact characteristics of Au/Ni deteriorated after annealing from 340 ℃ to 480 ℃ for 1 min. The results of scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy show that the Pt layer is an important factor in improving the contact characteristics. The Pt layer prevents the diffusion of In and Au, inhibits the formation of Au$_{3}$In metal compounds, and prevents the deterioration of the ohmic contact. The metal structures and optimized annealing process is expected to be helpful for obtaining high-performance InP-related devices.
2021, Vol. 38 
