Effects of Bulk Microdefects and Metallic Impurities on p–n Junction Leakage Currents in Silicon

Abstract

The effects of bulk microdefects and metallic impurities on leakage currents at p–n junctions have been evaluated quantitatively by relating leakage currents with bulk defects and metallic impurities, and the results are reported. Bulk defects and metallic impurities, which were introduced by appropriate thermal treatment and intentional contamination by spin-coating metal ion solutions onto the silicon surfaces, were shown to induce heavy leakage currents at p–n junctions, which had been manufactured by boron implantation and phosphorus diffusion. We found the bulk microdefects to be critical in causing leakage currents to flow and propose that their measurements be used as a means for the determination of the bulk defect densities. Die failure rates were also used for the evaluation of the effects of metallic impurities such as Cu, Ni, and Fe on the leakage currents.

Floating zone silicon wafer bonded to Czochralski silicon substrate by surface-activated bonding at room temperature for infrared complementary metal-oxide-semiconductor image sensors

“…In general, the leakage current of the pn-junction diode is increased by contamination with oxygen or a transition metal. 30,31) In Sect. 3.2, the oxygen in the reference sample was shown to diffuse from the inside to the surface during the device fabrication, as shown in Fig.…”