Bi-axially highly-strained Silicon-On-Insulator (sSOI) substrates with a tensile stress up to 2.5 GPa have been obtained by Smart CutTM technology. Thin strained silicon (sSi) layers epitaxially grown on relaxed Si0.6Ge0.4 virtual substrates (VS) were used as starting materials. The threading dislocation density in those sSi layers was in the low 105 cm-2. Some stacking faults were also present in those highly strained Si films. The evolution of this linear defect density was characterized as a function of the sSi thickness by Secco etch. 2.5 GPa sSOI wafers have been demonstrated in 200 mm diameter. Stress uniformity σ equal to 1.14% and 2 nm thickness range has been obtained for 8 nm thick sSi layers.
The Ultra-Thin SOI and BOX substrates are the foundation of Fully Depleted planar technology, a CMOS scaling solution for 20 nm node and beyond. Using the Smart CutTM technology, UTSOI substrates development, with SOI & BOX thickness reduced down to 12 & 25 nm respectively, is on the way to High Volume Manufacturing by the end of 2011. To improve device Vt variation control, SOI total layer thickness variation of less than +/- 1 nm for all the measured points and all the preproduction wafers is already achieved and +/- 0.5 nm variation is targeted. Tight SOI thickness variation at device scale and BOX thickness variation are also demonstrated.
Strained Silicon On Insulator wafers are today envisioned as a natural and powerfulenhancement to standard SOI and/or bulk-like strained Si layers. For MOSFETs applications, thisnew technology potentially combines enhanced devices scalability allowed by thin films andenhanced electron and hole mobility in strained silicon. This paper is intended to demonstrate byexperimental results how a layer transfer technique such as the Smart Cut™ technology can be usedto obtain good quality tensile Strained Silicon On insulator wafers. Detailed experiments andcharacterizations will be used to characterize these engineered substrates and show that they arecompatible with the applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.