Structural Mapping of Functional Ge Layers Grown on Graded SiGe Buffers for sub-10 nm CMOS Applications Using Advanced X-ray Nanodiffraction

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• 作者：Marie-Ingrid Richard ; Marvin H. Zoellner ; Gilbert A. Chahine ; Peter Zaumseil ; Giovanni Capellini ; Maik H盲berlen ; Peter Storck ; Tobias U. Sch眉lli ; Thomas Schroeder
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：December 9, 2015
• 年：2015
• 卷：7
• 期：48
• 页码：26696-26700
• 全文大小：433K
• ISSN：1944-8252

文摘

We report a detailed advanced materials characterization study on 40 nm thick strained germanium (Ge) layers integrated on 300 mm Si(001) wafers via strain-relaxed silicon鈥揼ermanium (SiGe) buffer layers. Fast-scanning X-ray microscopy is used to directly image structural inhomogeneities, lattice tilt, thickness, and strain of a functional Ge layer down to the sub-micrometer scale with a real space step size of 750 渭m. The structural study shows that the metastable Ge layer, pseudomorphically grown on Si_0.3Ge_0.7, exhibits an average compressive biaxial strain of 鈭?.27%. By applying a scan area of 100 脳 100 渭m², we observe microfluctuations of strain, lattice tilt, and thickness of ca. 卤0.03%, 卤0.05掳, and 卤0.8 nm, respectively. This study confirms the high materials homogeneity of the compressively strained Ge layer realized by the step-graded SiGe buffer approach on 300 mm Si wafers. This presents thus a promising materials science approach for advanced sub-10 nm complementary metal oxide鈥搒emiconductor applications based on strain-engineered Ge transistors to outperform current Si channel technologies.