Chong Wang

Progress on the Numerical Calculation of Electrical Characteristics of Strained SiGe Channel P-MOSFET

Recent progress in the computer simulation of strained SiGe channel p-MOSFET performance is reviewed. The electrical characteristics of strained SiGe channel p-MOSFET, such as threshold voltage, subthreshold characteristics, output characteristics, transconductance, quasistatic C-V characteristics and transfer characteristics, and the effects of Ge mole fraction on electrical characteristics, are well discussed. Finally, the development of strained SiGe channel p-MOSFET is prospected.

Red Light Emission from Silicon Created by Self-Ion Implantation and Thermal Annealing

Silicon substrates were implanted with Si ions at an energy of 60 keV to a dose of 5×1015 cm-2 followed by a thermal annealing at various temperatures up to 950 oC. Photoluminescence (PL) and infrared absorption (IRA) techniques have been used to characterize these samples. The PL peak positions at 2.07 eV and 1.93 eV undergo redshifts with the increasing annealing temperature. The two IRA peaks at 1080 cm-1 and 800 cm-1 are ascribed to the Si-O-Si asymmetric stretching and the Si-O bending vibration, respectively. The experimental results indicate that Si nanocrystals embedded in silicon oxide layer can be formed at the annealing temperature 800 oC or higher.

Advance in the Growth of Ordered Ge/Si Quantum Dots

Recent progress in the growth of ordered Ge/Si quantum dots (QDs) is reviewed. We focus on the detailed progresses of the Ge/Si multiple layers QDs and the preparation of Ge/Si QDs by ion beam irradiation. In addition, the growth of Ge/Si QDs on patterned substrate by using different preparation methods are also well discussed, such as nanosphere lithography technology, extreme ultra-violet interference lithography technology, nanoimprint lithography technology, etc.

Photoelectric Properties of the Doped Silicon with Carbon Family Elements

Today, silicon material plays an irreplaceable role in microelectronic of the information industry, however it don`t have a good emission characteristics. In order to explore the emission character, we calculated the electrons structure, absorbance of silicon doped with C, Si, Ge, Sn and Pb by the first-principles methods.

Advance of Ge/Si Quantum Dot Infrared Photodetector

The generation of quantum dots (QDs), the advantages and disadvantages of quantum dot infrared photodetector (QDIP) are briefly reviewed. Typical techniques for fabricating ordered Ge/Si QDs, the application of Ge/Si QDIP in optical communication and thermal imaging and the structure optimization are described. Finally, the key problems for improving the properties of Ge/Si QDs and Ge/Si QDIP, future trends and prospects are discussed.

The Development and Application of Si-Based Quantum Dot Resonant Tunneling Diodes

The development history of resonant tunneling diodes (RTD), the principle of quantum dot resonant tunneling diodes (QDRTD), and their characteristics of exceptional negative differential resistance (NDR) of QDRTD, are briefly introduced in this paper. The typical type and the design processes of QDRTD, and recent research progress are summarized in detail. Finally, the facing problems and the future necessary development directions of QDRTD are discussed.

Effect of Surface Passivation on Optical and Electronic Properties of Ultrathin Single-Layer Silicon Nanosheets Compared to Bulk Silicon

The binding energy, electronic structure and optical properties of ultrathin single-layer silicon nanosheets passivated with H-, H3C-, H2-N and HS-cluster were calculated using density functional theory based on plane-wave ultra-soft pseudopotential respectively. Firstly, the most stable configuration was selected from passivated configurations according to the lowest energy principle after calculating their total energies. Secondly the density of state and the band structure of the different passivated systems were calculated. It was found that different passivation clusters could affect the forbidden band, furthermore the passivated HS-cluster could notably decrease the width of forbidden band through electron transfer. Finally, the light absorption and reflection properties were also investigated. All results were conducive to the development of silicon-based optoelectronic devices.

Effects of Si Spacer-Layer on the Structure of Ge/Si Quantum Dots Bilayers Grown by Ion Beam Sputtering

A series of double-layer Ge/Si quantum dots are prepared by ion beam sputtering deposition (IBSD) on Si (100) substrates. The influences of deposition temperature and thickness of Si spacer-layer on the microstructure of double-layer Ge/Si quantum dots were characterized by using Atomic force microscopy (AFM) and Raman spectra technique. The results indicate that the density of the second layer islands firstly increases and then decreases with increasing the growth temperature of Si spacer-layers. In addition, increasing the thickness of Si spacer-layer, the islands merger phenomenon disappears. When the deposition thickness is larger than 40 nm, the islands on the upper-layer show the same features with the buried islands. The mechanism of three-factor-interactions of nanoislands is proposed to explain these phenomena, and our results can be used as a guidance to obtain optimum IBSD growth process for Ge/Si quantum-dot superlattices.