The superior carrier mobility of SiGe alloys make them a highly desirable channel material in complementary metal-oxide-semiconductor (CMOS) transistors. Passivation of the SiGe surface and the associated minimization of interface defects between SiGe channels and high- k dielectrics continues to be a challenge for fabrication of high-performance SiGe CMOS. A primary source of interface defects is interfacial GeO . This interfacial oxide can be decomposed using an oxygen-scavenging reactive gate metal, which nearly eliminates the interfacial oxides, thereby decreasing the amount of GeO at the interface; the remaining ultrathin interlayer is consistent with a SiO -rich interface. Density functional theory simulations demonstrate that a sub-0.5 nm thick SiO-rich surface layer can produce an electrically passivated HfO/SiGe interface. To form this SiO -rich interlayer, metal gate stack designs including Al/HfO/SiGe and Pd/Ti/TiN/nanolaminate (NL)/SiGe (NL: HfO-AlO) were investigated. As compared to the control Ni-gated devices, those with Al/HfO/SiGe gate stacks demonstrated more than an order of magnitude reduction in interface defect density with a sub-0.5 nm SiO -rich interfacial layer. To further increase the oxide capacitance, the devices were fabricated with a Ti oxygen scavenging layer separated from the HfO by a conductive TiN diffusion barrier (remote scavenging). The Pd/Ti/TiN/NL/SiGe structures exhibited significant capacitance enhancement along with a reduction in interface defect density.

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One of the main obstacles to performing electron crystallography analysis in a TEM is that the acquired electron diffraction data often exhibits some form of distortion introduced by the lens system. Recognizing this problem, Capitani et al. has proposed a method to detect such distortion, which is primarily elliptical, by using a single crystal standard. Once such elliptical distortion is characterized, electron diffraction data acquired later can then be corrected by means of image processing. However, it may be desirable to correct such distortion at the instrument level. In this article, a different approach to measuring diffraction elliptical distortion is proposed by characterizing diffraction ring patterns and it is demonstrated that by varying the objective lens stigmation settings, it is possible to eliminate this elliptical distortion completely.

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