PN junction in InSb has been made by Be ion implantation.I-V characteristics of the fabricated diode was measured at 77 K background.For the junction,the forward current obeys the I0eqv/βKT rule where β is 1.6.The reverse current density is 2.14×10-7 A/cm2 at-0.1 V and 3.9×10-6 A/cm2 at-1 V.The R0A product is 1.89×105 Ωcm2.The chip was loaded into the metal structure and tested.Its electro-optical performance meets the production requirement.