Strain at SiSiO2 interfaces studied by Micron-Raman spectroscopy

Theory and experiment of large numerical aperture objective Raman microscopy: application to the stress‐tensor determination in strained cubic materials

“…1. The upper integration limit for  in Eqn (8),  m , is half the aperture angle of the radiation cone probing the medium, 11 Equation (8) essentially expresses the scattered field intensity averaged over the objective solid angle in the medium. It should be noted that, in the point-like-focus approximation, the excitation field e e has been found to be virtually unaffected by the microscope objective 6 and is, consequently, not averaged.…”

“…Within the Si/SiO 2 /c-Si (or SOI) structure, a plane biaxial strain is introduced in the Si layer because of latticelength misfit, caused by the difference in the Si and SiO 2 thermal expansion coefficients, and occurring upon cooling the structure after thermal growth. 11 The stress tensor sought will be, consequently, of the form of s b from Eqn (36). Owing to the strain-induced increase in mobility of the electric carriers in the Si layer, the SOI structure is of significant interest for the microelectronic industry.…”

“…As a consequence, the 'forbidden' transverse optical phonon modes -TO1 and TO2 -become potentially observable, aside from the allowed LO mode. 6,11 Monitoring the strain-induced modifications in either the individual or in the collective response of all three phonon modes makes possible, at least in principle, the complete determination of the stress tensor.…”

“…Brunner et al 11 were apparently the first to take advantage of the full phonon-mode observability at large NAs for the determination of internal mechanical stress in Si structures. By using the Raman scattering selection rule combined with finite collection-angle modeling, they were able to monitor all phonon modes in [001]-oriented SiO 2 /Si structures.…”

Evaluation of Kink Generation Rate and Step Flow Velocity on Si(111) during Wet Etching

“…The extrapolated speed at zero length V 0 (¼ 110 nm/h) is due to non-negligible kink generation at anomalous places of contact between SiO 2 lines and steps because it should have a unique reactivity. [26][27][28] Assuming that the etching of a single atomic row is immediately carried out before the next kink generation, the step flow velocity V S for short steps is expressed as…”