On the microstructure of Si coimplanted with H+ and He+ ions at moderate energies

Abstract

Mechanism of the Smart Cut™ layer transfer in silicon by hydrogen and helium coimplantation in the medium dose range J. Appl. Phys. 97, 083527 (2005) We report on the microstructure of silicon coimplanted with hydrogen and helium ions at moderate energies. X-ray diffraction investigations in as-implanted samples show the direct correlation between the lattice strain and implanted ion depth profiles. The measured strain is examined in the framework of solid mechanics and its physical origin is discussed. The microstructure evolution of the samples subjected to intermediate temperature annealing ͑350°C͒ is elucidated through transmission electron microscopy. Gas-filled cavities in the form of nanocracks and spherical bubbles appear at different relative concentration, size, and depth location, depending on the total fluence. These different microstructure evolutions are connected with the surface exfoliation behavior of samples annealed at high temperature ͑700°C͒, determining the optimal conditions for thick layer transfer. 1.5 m thick Si films are then obtained onto glass substrates.

Impact of He and H relative depth distributions on the result of sequential He+ and H+ ion implantation and annealing in silicon

“…Ion implantation of hydrogen and helium is widely used in laboratories and industries to fracture and transfer thin layers of various materials onto different substrates. [1][2][3][4][5][6] This process, named Smart Cut, 7 is applied to fabricate almost all the Silicon-On-Insulator (SOI) wafers routinely used by the microelectronics and sensor industries. Initially, the process was based on the sole implantation of hydrogen ions at a high fluence followed by bonding and annealing.…”

Nanoscale organization by elastic interactions between H and He platelets in Si

“…The pattern is characteristic of a lattice dilatation gradient of Gaussian-like shape along the normal to the surface (z-direction defined as [001] direction). [8][9][10] The XRD diffraction pattern was simulated using the web-based code GID_SL written by Stepanov. 13 The simulation of the curve (displayed as dotted line in Fig.…”

“…The origin of strain/stress in H-implanted Si is related to the introduction of foreign atoms and lattice disorder in the material. 8,10,[14][15][16] These structural modifications cause a localized increase of volume within the damaged layer, or an isotropic intrinsic strain e. 14-16 Along the z-direction perpendicular to the surface, there is no restriction to deformation and the system can assume its new configuration. In the directions parallel to the surface (defined here as x and y), however, the thick substrate imposes a restriction to relaxation.…”

“…11 12 the projected ion range Rp is of %200 nm from the surface. After implantation, the lattice strain (Dd/d) z associated to the implanted layer, [8][9][10] appearing along the direction normal to the surface and referred to as out-of-plane strain, was measured by X-ray diffraction (XRD) scans around the (004) reflection of the Si substrate. The experiments were performed using a Philips X'Pert equipment.…”

Lattice Strain Measurements in Hydrogen Implanted Materials for Layer Transfer Processes

“…Silicon has been co-implanted with helium and hydrogen by some authors (Duo et al, 2001), (Reboh et al, 2010). They showed the sensitivity of the measurements to the annealing temperature, the dose and the nature of the implanted ions.…”