| Summary: | 碩士 === 大葉大學 === 電機工程學系 === 96 === Silicon dioxide (SiO2) has been grown on SiGe film by using liquid-phase deposition (LPD) methods with H2SiF6 and H3BO3 at room temperature. In this study, the concentrations of H2SiF6 and H3BO3 were 0.4 and 0.01 M, respectively, for temperature of 30 ℃. We found that the growth rate of SiO2 would increase with increasing of temperature and H3BO3 concentration.
No Ge pileup was found at interface of SiGe and SiO2 by using Auger electron spectrometer (AES) and electron spectroscopy of chemical analysis (ESCA) showed that the Si-2p appears at 103.4 eV with a full width at half maximum (FWHM) of 1.48 eV. The infrared absorption spectrum of SiO2 was measured by Fourier transform infrared spectroscopy (FTIR) and revealed that the wave numbers located 810 and 1100㎝-1, belonging to to the bending stretching and vibration modes of Si-O-Si bonding, moreover a peak of Si-F bonding appeared at 933㎝-1.
A metal-oxide-semiconductor (MOS) device of SiGe was fabricated with above conditions. A leakage current density of 8.69×10-9 A/㎝2 was found at 2 MV/cm. With increasing of temperature to 400 ℃, the fixed oxide charge density and interface charge density were improver from 3.82×1010 cm- and 3.25×1011 eV-1㎝-2 to 4.77×109 cm-2 and 1.15×1011 eV-1㎝-2, respectively.
For a study of MOS photodetectors, the dark current was reduced from the non-annealed samples of 3.25×10-8A to 4.46×10-9A for the 400 ℃ annealed samples. The photo to dark current ratio was 3.17×104 for 200 ℃ annealed samples with 850 nm illumination. The responsivity was 0.567A/W for non-annealed samples.
Keywords：liquid-phase deposition、metal-oxide-semiconductor、photodetectors
|
|---|
