Application of real time spectroscopic ellipsometry for high resolution depth profiling of compositionally graded amorphous silicon alloy thin films

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.118972· OSTI ID:565263

Fujiwara, H; Koh, J; Wronski, C R; Collins, R W ^[1]

---

1. Materials Research Laboratory and Departments of Electrical Engineering and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

Real time spectroscopic ellipsometry (RTSE) has been applied to characterize compositionally graded amorphous silicon-carbon alloy (a-Si{sub 1{minus}x}C{sub x}:H) thin films, prepared using continuous variations in the flow ratio z=[CH{sub 4}]/{l_brace}[SiH{sub 4}]+[CH{sub 4}]{r_brace} during rf plasma-enhanced chemical vapor deposition. Triangular variations in z versus time, yielding 50{endash}130-{Angstrom}-thick a-Si{sub 1{minus}x}C{sub x}:H graded layers with 0.02{le}x{le}0.24, were applied in order to assess the performance of the RTSE data analysis procedure. This procedure employs a four-medium virtual interface approximation, and returns the time evolution of (i) the near-surface C content, (ii) the instantaneous growth rate, and (iii) the surface roughness layer thickness. In the depth profiles of the graded structures, an apparent resolution of {approximately}10 {Angstrom} is obtained with a composition uncertainty of {plus_minus}0.004. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 565263
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 16 Vol. 70; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
CHEMICAL COMPOSITION
CHEMICAL VAPOR DEPOSITION
ELLIPSOMETRY
ENERGY GAP
GERMANIUM SILICIDES
HYDROGEN
OPTICAL REFLECTION
STOICHIOMETRY
SURFACES
THIN FILMS