Ordering and self-organization in nanocrystalline silicon

Abstract

The spontaneous formation of organized nanocrystals in semiconductors has been observed during heteroepitaxial growth and chemical synthesis. The ability to fabricate size-controlled silicon nanocrystals encapsulated by insulating SiO2 would be of significant interest to the microelectronics industry. But reproducible manufacture of such crystals is hampered by the amorphous nature of SiO2 and the differing thermal expansion coefficients of the two materials. Previous attempts to fabricate Si nanocrystals failed to achieve control over their shape and crystallographic orientation, the latter property being important in systems such as Si quantum dots. Here we report the self-organization of Si nanocrystals larger than 80 A into brick-shaped crystallites oriented along the (111) crystallographic direction. The nanocrystals are formed by the solid-phase crystallization of nanometre-thick layers of amorphous Si confined between SiO2 layers. The shape and orientation of the crystallites results in relatively narrow photoluminescence, whereas isotropic particles produce qualitatively different, broad light emission. Our results should aid the development of maskless, reproducible Si nanofabrication techniques.

Self-organized nanopatterning of silicon surfaces by ion beam sputtering

“…This is naturally due to its well-known advantages with respect to integration [5] in microelectronic, electro-optical, electrochemical, electromechanical, sensing, and laser devices [6][7][8], and to the interesting properties of nanostructured silicon [9]. For instance, low-dimensional Si structures like nanowires are recently displaying a number of promising, novel structural, electronic, and transport properties [10].…”

New CMOS-compatible platforms based on silicon nitride and Hydex for nonlinear optics

“…Over the last 10 years the achievements reported in SOI fabricated using CMOS technology that exploit both linear and nonlinear optical phenomena [2,23] are impressive [23 -39], ranging from optical buffers [24], optical interconnects [25][26][27], ring resonators [28,29], Raman gain and lasing [30 -32], time lensing [13,33], slow light based on photonic crystals [34 -36], optical regeneration [9], parametric gain [5, 37 -39] to the promise of direct optical transitions [40,41], and even correlated photon pair generation [42].…”

Charge injection and trapping in silicon nanocrystals

“…[1][2][3][4] The nanometer-scale size of these crystals leads to novel electronic and optical properties associated with quantum confinement and single-electron charging effects. These properties have been exploited for the fabrication of single-electron transistors and memories, 1,5 electron emitters, 6 and silicon light emitting devices.…”