Yu. M. Degot, O. N. Zabenkin, N. N. Kichina, N. V. Kravchanko, A. V. Kulymanov, Yu. V. Lobilov, O. V. Ogneva, M. A. Trishenkov, P. E. Khakuashev, I. V. Tchinareva
ORION Research-and-Production Association, Moscow, Russia
We describe the fabrication and performance of Ge p—n-photodiodes that have photosensitive areas with diameters of 1.1 mm. The photodiodes have hign sensitivity at 1.06 and 1.55 mm. The substrates used in this work are n-type wafers with a carrier concentration of 5Ч1015 cm-3. Boron ions are implanted to form a p—n-juction. To prevent edge breakdown the diode is surrounded by a guard ring prodused by berillium implantation. All implantations are performed with photoresist masks through the passivation layer, which acts as a screening oxide. Ti and Au are used as contacts. Typical responsivity is over 0.4 A/W at 1.06 mm, 0.7 A/W at 1.55 mm. At 20 °C, –10 V, the capacitance is 80 pF, dark current is 5 mkA.
