Non-destructive characterization of nitrogen-implanted silicon-on-insulator structures by spectroscopic ellipsometry

✍ Scribed by M. Fried; T. Lohner; J.M.M. De Nijs; A. Van Silfhout; L.J. Hanekamp; N.Q. Khanh; Z. Laczik; J. Gyulai

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 465 KB
• Volume: 2
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(89)90087-1

✦ Synopsis

1. Introduction

Silicon-on-insulator (SO1) structures implanted with 200 or 400 keV N ÷ ions at a dose of 7.5×1017cm 2 were studied by spectroscopic ellipsometry (SE). The SE measurements were carried out in the 300-700 nm wavelength (4.13-1.78 eV photon energy) range. The SE data were analysed by the conventional method of using appropriate optical models" and linear regression analysis. We applied a seven-layer model (a surface oxide layer, a thick silicon layer, upper two inter-]'ace layers, a thick nitride layer and lower two interface layers) with good results. The fitted parameters were the layer thicknesses and compositions. The results' were compared with data obtained from Rutherford backscattering spectroscopy (RBS) and transmission electron microscopy. The sensitivity of our optical model and fitting technique was good enough to distinguish between the silicon-rich transition layers near the upper and lower interfaces" of the nitride layer, which are unresolvable in RBS measurements.