Lateral Ga_0.47In_0.53As and GaAs p-i-n Photodetectors by Self-Aligned Diffusion

Contact-self-aligned diffusion and compositional mixing has been utilized in the fabrication of lateral p-i-n photodetectors in Ga0.47In0.53As and GaAs for 1.3 and 0.85 μm wavelength operation. The p-type contact and diffusion utilizes W(Zn) metallurgy and the n-type contact and diffusion utilizes MoGe2 metallurgy. Bandwidths exceeding 7.5 and 18.0 GHz, respectively, have been obtained using these structures with bias voltages of ≃5 V. The performance, ease of fabrication, and process compatibility make these devices suitable for integration in digital circuits employing field-effect transistors. © 1992 IEEE