ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
An overview of various cleaning procedures for silicon surfaces is presented. Because in-situcleaning becomes more and more important for nanotechnology the paper concentrates on physicaland dry chemical techniques.As standard ex-situ wet chemical cleaning has a significant impact on surface quality und thusdevice properties, its influence on further processes is also considered. Oxygen and carbon areunavoidable contaminations after wet chemical treatment and therefore we discuss their in-situremoval as one of the main goals of modern silicon substrate cleaning. As surface roughnessstrongly influences the electrical quality of interfaces for epitaxy and dielectric growth, weconcentrate on techniques, which meet this requirement.It will be shown that multi-step thermal sequences in combination with simultaneous passivationof the clean surface are necessary in order to avoid recontamination. This can be achieved not onlyfor ultra hich vacuum but also for inert gas atmosphere. In this case the process gases have to beextremely purified and the residual partial pressure of contaminats such as oxygen and carbon hasto be negligible.It will be demonstrated that 800°C is an upper limit for thermal treatment of silicon surfaces inthe presence of carbon because at this temperature SiC formation in combination with a highmobility of silicon monomers leads to surface roughness. In addition mechanical stress causesdislocations and crystal defects
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.573-574.77.pdf
