Selective Epitaxial Growth Of Si And Relaxed Ge By UHV-CVD In Si(001) Windows

• Published in: ECS transactions Vol. 3; no. 7; pp. 593 - 598
• Main Authors: Fossard, Frédéric, Halbwax, Mathieu, Yam, Vy, Nguyen, Huu Lam, Mathet, Véronique, Cammilleri, Davide, Débarre, Dominique, Boulmer, Jacques, Bouchier, Daniel
• Format: Journal Article
• Language: English
• Published: 20.10.2006
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.2355856

Relaxed germanium was deposited following a low temperature-high temperature procedure by ultrahigh vacuum chemical vapor deposition in Si trenches opened through a SiO 2 mask. The resulting growth is selective, the germanium fills the Si trenches and evolves towards a roof-shaped morphology limited by (001), {113} and {111} facets. The evolution in height of the Ge structure depends on the trench width, and can be understood by considering a growth rate in the direction equal to 22% of that measured along the axis. At last, a surprisingly strong Ge diffusion under the SiO 2 mask was revealed by selective chemical etching. Such a phenomenon was unexpected because no diffusion through the Si/Ge interface was previously observed on plain wafer.