The Application of Solid Phase Epitaxy for the Incorporation of Substitutional Carbon in Silicon

Carbon was substitutionally incorporated into silicon using ion implantation and solid phase epitaxy (SPE) to regenerate a high quality crystalline substrate. Carbon was implanted into Si(100) substrates using a single implant of 25 keV at doses ranging from 1.75 × 1015 to 1.05 × 1016/cm2. After carbon implantation half of the substrates were amorphized using a silicon implant. All of the wafers were subjected to a 700°C anneal in N2 ambient for 30 minutes to induce SPE regrowth of the implanted regions. FTIR, SIMS, RBS, and TEM were used to characterize the samples. Results indicate that carbon was substitutionally incorporated into the silicon lattice, but that some carbon did precipitate to form silicon carbide. Post-amorphization improved regrowth of implanted regions in lower dose implanted wafers. Electrical measurements on diode structures indicate that the band gap was reduced for carbon incorporation at these concentrations.