Confinement and transport in silicon based quantum structures

Crystallized Si QWs embedded between SiO
2
barrier layers were fabricated by remote plasma enhanced chemical vapor deposition of Si/SiO
2
and Si/SiO
x
stacks and subsequent high temperature annealing. Using SiO
x
instead of SiO
2
strongly enhances the overall crystallinity and the nanocrystallite size of the Si QWs. The phase separation of the SiO
x
into Si and SiO
2
increases the thickness of the Si QWs and yields thin SiO
2
barriers. Photoluminescence measurements on annealed stacks showed a quantum confinement of carriers within the Si QWs. The high degree of crystallization and the decrease of SiO
2
barrier height and thickness as well as possible shunting between adjacent Si layers improve the conductivity of annealed Si/SiO
x
stacks by up to seven orders of magnitude compared to Si/SiO
2
stacks.