Effects of oxygen on selective silicon deposition using disilane

• Published in: Materials letters Vol. 38; no. 6; pp. 418 - 422
• Main Authors: O'Neil, Patricia A., Öztürk, Mehmet C., Batchelor, Alan D., Maher, Dennis M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-03-1999; Elsevier
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; CVD; Disilane; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Selective silicon deposition; Silicon; CVD; Disilane; 68.55.−a; 73.61.Cw; Silicon; 68.55.Jk; Selective silicon deposition; Semiconductor materials; Epitaxy; Roughness; Operating mode; Surfaces; Crystal growth from vapors; Experimental study; Precursor; Characterization; Thin films; Selective growth; Partial pressure; Nonmetals; Morphology; Oxygen pressure; Ultrahigh vacuum
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(98)00200-6

Using Si
2H
6 in an ultrahigh vacuum rapid thermal chemical vapor deposition reactor, we have investigated the role of high levels of oxygen (>5×10
−6 Torr) introduced during selective silicon deposition. The effects of oxygen have been investigated with regard to oxygen incorporation, selectivity with respect to thermal SiO
2, growth rate, and epitaxial quality. The addition of oxygen was found to enhance the inherent process selectivity of Si
2H
6 to SiO
2 while causing no reduction in the silicon growth rate or measurable oxygen incorporation into the growing film for oxygen pressures below 5×10
−5 Torr. Contrary to published reports, the silicon film was devoid of the pyramidal defects usually characteristic to highly oxygenated processes. The silicon surface morphology, however, exhibited increased roughness with increasing oxygen partial pressure. The surface roughness is believed to be a result of the high levels of oxygen adsorbed at the initial growth surface.