熱酸化シリコン薄膜へのゲルマニウム負イオン斜め注入とフォトルミネッセンス評価

抄録

  Ge embedded SiO₂ films are expected as hopeful blue-ultraviolet light source. We research for low voltage electroluminescence (EL) from Ge implanted SiO₂ thin film. We have obtained EL emission by using SiO₂ thin film with thickness of 50 nm by applying DC 15 V. In order to realize low-voltage EL at less than 10 V, to control optical emission site is very important. In this work, we implanted Ge⁻ at multi-energy of 50 keV, 20 keV, 10 keV into 50 nm SiO₂ thin layer at the angle of 30°, 45°, 60°. Then the samples were annealed at two stages each for 1 hour: the first stage was in N₂ flow at temperature of 700°C, and the second was in air flow at 600°C. X-ray photoelectron spectroscopy (XPS) was used to analyze Ge profile of the 60° implantation sample, and photoluminescence (PL) was studied. As a result, XPS showed Ge distribution peak at shallow region of 8 nm and it corresponded to the simulation by TRIM-DYN. PL spectra at 290 and 390 nm were obtained. PL intensity from 60° and 45° tilt type sample were stronger than that from 30° tilt type, therefore we investigated that light emission center would be created in the shallow depth less than 25 nm.