Formation Of 3C-SiC Research Articles

High-resistance thermally stable silicon layers produced by the CO+ ion implantation

The high-resistance silicon layers were formed by the CO+ ion implantation of silicon substrates and a subsequent annealing at 1100 °C. The structural and electric properties of the ion-implanted layers were studied. The formation of 3C-SiC and 6H-SiC nanocrystals was obtained in the ion implanted layers. It was shown that the formation of SiC precipitates results in the positive charge compensation in the buried SiO2 layer of a silicon-on-insulator structure. The origin of the obtained results is discussed.

Investigation of the Growth of 3C-SiC on Si by Vapor-Liquid-Solid ( VLS ) Transport

In this work, the growth by Vapour-Liquid-Solid (VLS) mechanism of 3C-SiC on silicon substrate is reported. Firstly, a germanium layer is deposited on the substrate. Then the temperature of the sample is increased above Ge melting point in order to form a SiGe liquid phase by reaction with the substrate. Upon reaching the target temperature (1100-1300°C) the VLS growth starts with the injection of propane in the reactor. Both Raman spectrometry and X-Ray diffraction analyses evidenced the formation of 3C-SiC on every sample. However, this SiC deposit, a few micrometers thick, is always found to be polycrystalline though textured. In parallel, the presence of an epitaxial Si-Ge alloy, whose composition depends on the growth temperature, was systematically detected between Si and SiC.

Structure and Photoluminescence Properties of Ion Beam Synthesized SiC Nanoparticles in Si

Silicon carbide nanoparticles were synthesized in Si(100) wafers by 300 keV C+ ion implantation at elevated substrate temperatures of 550, 650 and 700 degrees C. The implantation has been carried out upto a fluence of 2 x 10(17) ions/cm2 with a constant current density 1.2 microA/cm2. GIXRD analysis on the implanted sample confirms the formation of 3C-SiC. XTEM studies of sample implanted at 650 degrees C show that size of SiC nanoparticles is 6 nm at a depth 0.6 microm from the sample surface. PL spectrum of sample implanted at different temperatures showed a peak at 2.45 eV and 2.3 eV and the intensity of PL peak increases with implantation temperature. The peak at 2.45 eV corresponds to blue shifted emission from SiC nanoparticles having size 6 nm. The peak at 2.3 eV is assigned to the SiC nanoparticles with enhanced d-value.

Crystalline quality of 3C-SiC formed by high-fluence C +-implanted Si

Carbon ions at 40 keV were implanted into (1 0 0) high-purity p-type silicon wafers at 400 °C to a fluence of 6.5 × 10 17 ions/cm 2. Subsequent thermal annealing of the implanted samples was performed in a diffusion furnace at atmospheric pressure with inert nitrogen ambient at 1100 °C. Time-of-flight energy elastic recoil detection analysis (ToF-E ERDA) was used to investigate depth distributions of the implanted ions. Infrared transmittance (IR) and Raman scattering measurements were used to characterize the formation of SiC in the implanted Si substrate. X-ray diffraction analysis (XRD) was used to characterize the crystalline quality in the surface layer of the sample. The formation of 3C-SiC and its crystalline structure obtained from the above mentioned techniques was finally confirmed by transmission electron microscopy (TEM). The results show that 3C-SiC is directly formed during implantation, and that the subsequent high-temperature annealing enhances the quality of the poly-crystalline SiC.

Linear expansion coefficient of the SiC/Si biomorphic composite

In the temperature range 100–650 K, the linear expansion coefficient β was measured for the SiC/Si biomorphic composite, a new cellular ecoceramic fabricated from a porous cellular carbon matrix prepared through pyrolysis of wood (white eucalyptus) in an argon ambient with subsequent infiltration of molten Si into the channels of the matrix and the formation of 3C-SiC. The SiC/Si samples studied had an “excess” ∼30% volume concentration of Si and a porosity of ∼13–15%. The measurements were conducted on samples cut along (β∥) and across (β⊥) the tree growth direction. The measured values of β(T) of SiC/Si are compared with literature data available for the linear expansion coefficients of Si and 3C-SiC.

Epitaxial growth of strained Si 1− yC y films by the hot-wire cell method and its application to metal oxide semiconductor devices

We succeeded in obtaining strained Si 1− y C y films at a substrate temperature of 200 °C by the hot-wire cell method. The substitutional carbon concentration in films annealed at 700 °C was 0.9%, while it was limited to 0.13% for a sample grown by gas-source molecular beam epitaxy (MBE) at a substrate temperature of 700 °C. We investigated the thermal stability of strained Si 1− y C y films for device application. Annealing at over 900 °C caused the formation of 3C-SiC and relaxation of the strain occurred. From this result, we found that the process temperature should be lower than 800 °C. A low-temperature MOSFET process, in which all process temperatures after deposition of Si 1− y C y were lower than 800 °C, was developed and a strained Si 1− y C y MOSFET was fabricated.