Chuanling Men

Characteristics and polarization-enhanced model of wurtzite aluminum nitride thin films synthesized on Si(100) substrates by pulsed laser deposition

AlN thin films were fabricated on silicon (100) substrates by pulsed laser deposition and their properties are investigated. Our results indicate that the AlN films have a wurtzite crystalline structure with (002) preferential orientation over a large range of temperatures from room temperature to 800 °C. With an increase in substrate temperature, the films undergo a transition from nanocrystalline to large polycrystalline morphology, and at the same time the surface roughness increases due to larger columnar grain size. Electrical measurements show that there is a high dynamic charge density in the AlN films, and a polarization-enhanced mechanism is proposed to interpret the voltage–charge hysteresis loops observed in the samples.

AlN thin films grown by ion-beam-enhanced deposition and its application to SOI materials

Large area aluminium nitride (AlN) films were synthesized by ion-beam-enhanced deposition (IBED) method. Characterizations of the films revealed that the quality of the films strongly depends on the evaporation rate of Al. The best quality was obtained with the evaporation rate of Al at 0.5 A/s, and the film has excellent dielectric property and a smoother surface with roughness RMS values of 0.13 nm, and could be bonded directly with a hydrogen-implanted wafer at room temperature. Consequently, a novel silicon-on-insulator structure with AlN as insulating layer has been formed by the Smart-Cut process.

Fabrication of silicon-on-AlN novel structure and its residual strain characterization

Self-heating effects in silicon-on-insulator (SOI) devices limit the applicability of SOI materials in electronics in cases where high power consumption is expected. AlN becomes a promising alternative to SiO2 layer in traditional SOI materials. For the first time, a novel silicon-on-aluminum-nitride (SOAN) structure has been fabricated by the smartcut process to alleviate the self-heating effects. The AlN films were synthesized on 4 00 Si(1 0 0) substrate by ion-beamenhanced deposition technique, followed by the smart-cut process. Cross-sectional transmission electron microscopy micrograph confirms the formation of the SOAN structure. High-resolution transmission electron microscopy image and spreading resistance profile results serve evidence that the top silicon has good crystalline quality and electrical quality similar to the Si substrate. High-resolution X-ray diffraction was employed to study the residual strain in the formed SOAN structure and indicates that the residual lattice strain in the top silicon layer varied from tensile to little compressive after as-received SOI samples annealed at 11001C for an hour. r 2002 Elsevier Science B.V. All rights reserved.

Oxygen profile engineering in silicon by germanium addition and high-temperature annealing

The formation of multilayer structures in oxygen-implanted silicon by the introduction of germanium is reported. Our results show that the oxygen distribution can be split under carefully controlled annealing conditions. The typical annealing process consists of first raising the furnace temperature from 600 to 1200 °C within 30 min and then holding the temperature at 1200 °C for 2 h. The faster crystallization rate of amorphous silicon germanium (SiGe) and germanium rejection from the oxide contribute to the final multilayer structure. Our findings suggest that oxygen profile engineering is possible and single-energy ion implantation can be utilized to fabricate multilayer structures containing multiple buried oxide layers. In addition, our results suggest that, in SiGe-on-insulator fabrication, the annealing step at a moderate temperature or a slow temperature ramp-up rate during the high-temperature annealing step is much more critical than in conventional silicon-on-insulator fabrication.

Fabrication of silicon-on-insulator structure with Si3N4 as buried insulating films by epitaxial layer transfer

Abstract One of the main disadvantages of standard silicon-on-insulator (SOI) materials is that the buried oxide layer has poor thermal conductivity and so self-heating effects can be a problem. In order to minimize the above effects, the single-crystalline Si/Si 3 N 4 /substrate-Si structures were successfully formed using electron beam evaporation of silicon on porous silicon and epitaxial layer transfer for the first time. The SOI structures were investigated by high-resolution cross-sectional transmission electron microscopy and spreading resistance profile. Experimental results show that the buried Si 3 N 4 layer has an amorphous structure and the new SOI sample has good structural and electrical properties.

Fabrication of silicon-on-insulator-multilayer structure by epitaxial layer transfer

Due to the very low thermal conductivity of the thick-buried oxide layer, the silicon-on-insulator(SOI) power devices have an inherent self-heating effect, which limits their operation at high current level. Adopting the new silicon-on-insulator-multilager (SOIM) structures is a good solution to reduce the self-heating effect. In this paper, the SOIM structures were successfully produced by electron beam evaporation of silicon on porous silicon and epitaxial layer transfer. The quality of the structures was investigated by XTEM and SRP. Experimental results show that the buried Si3N4 layer is amorphous and the new SOIM sample has good structural and electical properties.

Corrugated plasmonic cavity for enhanced intersubband photodetection

We study the optical properties of a corrugated plasmonic cavity consisting of a perforated metal film and a flat metal sheet separated by a semiconductor spacer. Corrugation enhances dramatically the coupling between the propagating surface plasmon and the Fabry-Perot mode and induces Rabi-like splitting forming bright bonding and dark anti-bonding modes. The anti-bonding mode exhibits considerably higher volume-averaged field enhancement factors (∼16.5 for E-field and ∼14.1 for Ez-component) than its bonding counterpart as well as a very high polarization conversion ratio (∼85.5%) from transverse electric to transverse magnetic waves. These characteristics make the corrugation induced anti-bonding mode particularly suitable for semiconductor quantum well intersubband photodetectors. Our work may provide a general guideline to the design of metamaterial-coupled intersubband hybrid devices for practical applications.

H distribution and strain evolution in SiGe/Si heterostructure implanted by H dimers

A 75nm Si0.84Ge0.16 film was grown at 500°C with Si2H6 and GeH4 precursors. After depositing an oxide layer on the top, the samples were implanted with ions at an energy of 38keV, and a dose of 3.5 × 1016cm-2. These implanted samples were annealed in the temperature range from 400°C to 700°C. H redistribution occurs during this process. Meanwhile, great tensile strain was introduced by implantation into the SiGe/Si heterostructure layers and following annealing relieved the strain. High temperature annealing almost fully relaxed the SiGe layer.