中国物理B ›› 2017, Vol. 26 ›› Issue (5): 56801-056801.doi: 10.1088/1674-1056/26/5/056801

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Effect of substrate temperature on the morphological, structural, and optical properties of RF sputtered Ge1-xSnx films on Si substrate

H Mahmodi, M R Hashim   

  1. 1 Nano-Optoelectronics Research Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Pulau Penang, Malaysia;
    2 Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Pulau Penang, Malaysia
  • 收稿日期:2016-10-14 修回日期:2017-01-26 出版日期:2017-05-05 发布日期:2017-05-05
  • 通讯作者: H Mahmodi E-mail:hadi.mahmodi@gmail.com
  • 基金资助:
    Project supported by the Universiti Sains Malaysia (Grant No. 1001/PFIZIK/846072).

Effect of substrate temperature on the morphological, structural, and optical properties of RF sputtered Ge1-xSnx films on Si substrate

H Mahmodi1, M R Hashim2   

  1. 1 Nano-Optoelectronics Research Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Pulau Penang, Malaysia;
    2 Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 USM, Pulau Penang, Malaysia
  • Received:2016-10-14 Revised:2017-01-26 Online:2017-05-05 Published:2017-05-05
  • Contact: H Mahmodi E-mail:hadi.mahmodi@gmail.com
  • Supported by:
    Project supported by the Universiti Sains Malaysia (Grant No. 1001/PFIZIK/846072).

摘要: In this study, Ge1-xSnx alloy films are co-sputtered on Si(100) substrates using RF magnetron sputtering at different substrate temperatures. Scanning electron micrographs, atomic force microscopy (AFM), Raman spectroscopy, and x-ray photoemission spectroscopy (XPS) are conducted to investigate the effect of substrate temperature on the structural and optical properties of grown GeSn alloy films. AFM results show that RMS surface roughness of the films increases from 1.02 to 2.30 nm when raising the substrate temperature. This increase could be due to Sn surface segregation that occurs when raising the substrate temperature. Raman spectra exhibits the lowest FWHM value and highest phonon intensity for a film sputtered at 140 ℃. The spectra show that decreasing the deposition temperature to 140 ℃ improves the crystalline quality of the alloy films and increases nanocrystalline phase formation. The results of Raman spectra and XPS confirm Ge-Sn bond formation. The optoelectronic characteristics of fabricated metal-semiconductor-metal photodetectors on sputtered samples at room temperature (RT) and 140 ℃ are studied in the dark and under illumination. The sample sputtered at 140 ℃ performs better than the RT sputtered sample.

关键词: GeSn, magnetron sputtering, Raman scattering, x-ray photoemission spectroscopy

Abstract: In this study, Ge1-xSnx alloy films are co-sputtered on Si(100) substrates using RF magnetron sputtering at different substrate temperatures. Scanning electron micrographs, atomic force microscopy (AFM), Raman spectroscopy, and x-ray photoemission spectroscopy (XPS) are conducted to investigate the effect of substrate temperature on the structural and optical properties of grown GeSn alloy films. AFM results show that RMS surface roughness of the films increases from 1.02 to 2.30 nm when raising the substrate temperature. This increase could be due to Sn surface segregation that occurs when raising the substrate temperature. Raman spectra exhibits the lowest FWHM value and highest phonon intensity for a film sputtered at 140 ℃. The spectra show that decreasing the deposition temperature to 140 ℃ improves the crystalline quality of the alloy films and increases nanocrystalline phase formation. The results of Raman spectra and XPS confirm Ge-Sn bond formation. The optoelectronic characteristics of fabricated metal-semiconductor-metal photodetectors on sputtered samples at room temperature (RT) and 140 ℃ are studied in the dark and under illumination. The sample sputtered at 140 ℃ performs better than the RT sputtered sample.

Key words: GeSn, magnetron sputtering, Raman scattering, x-ray photoemission spectroscopy

中图分类号:  (Semiconductors)

  • 68.55.ag
68.55.-a (Thin film structure and morphology) 74.25.nd (Raman and optical spectroscopy) 82.80.Pv (Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.))