Light-Emitting Diodes Fabricated From Carbon Ions Implanted Into p-Type Silicon

• Published in: IEEE transactions on electron devices 2015-03, Vol.62 (3), p.914-918
• Main Authors: Purdy, Sarah K., Knights, Andrew P., Bradley, Michael Patrick, Gap Soo Chang
• Format: Article
• Language: English
• Subjects: Amorphous silicon (a-Si); Educational institutions; electroluminescence (EL); electron energy loss spectroscopy (EELS); ion implantation; Ions; Light emitting diodes; light-emitting diode (LED); Physics; Schottky diode; Schottky diodes; Silicon; Silicon carbide; silicon carbide (SiC); transmission electron microscopy (TEM)
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2015.2395995

Silicon-based light-emitting diodes (LEDs) are fabricated using p-type silicon implanted with C + ions and postannealed at 1000 °C in flowing nitrogen. The ion implantation is carried out at ambient temperature (AT) and 400 °C to investigate the influence of high-temperature implantation on the luminescence of LEDs. Transmission electron microscopy shows a near-surface layer of amorphous silicon (a-Si) with nanoscale carbon-rich inclusions in both ambient and heated targets while an additional polycrystalline Si layer is observed in the heated target only. A Schottky diode is constructed from C + -implanted Si (C:Si) with a semitransparent gold layer on the implanted surface and aluminum on the back of the target. Contact firing at 400 °C in flowing nitrogen is used to optimize diode performance. Turn-ON voltage is determined to be about 3 V for all devices. Electroluminescence (EL) spectra show visible orange-red emission indicating luminescence primarily due to a-Si and Si nanoparticles in the LEDs fabricated from C:Si implanted at AT. The high-temperature samples produced EL attributed to a-Si and porous silicon carbide.