Array-ordered single-crystal silicon nanowires were fabricated by the nanochannel-aluminal and CVD method. The average length and diameter of the nanowires is about 10 mm and 60 nm, respectively. A study of the Raman spectrum of the nanowires shows that the Raman shift to low frequency is due to the quantum confinement effect, which is discussed by using the phonon confinement model. Also we determine the peaks of the Raman spectrum to be corresponding to that of crystal silicon (c-Si).

CdS nanotubes have been prepared by means of chemical bath deposition (CBD) and nanochannel alumina (NCA) template. X-ray diffraction (XRD) and selected area electron diffraction (SAED) indicate that the nanotubes are of cubic structure. Transmission electron microscopy (TEM) shows the diameters of nanotubes are around 50nm. Furthermore, high-resolution TEM (HRTEM) reveals a clear lattice image of {1 1 1} planes in the wall of a CdS nanotube. The directional growth of nanotubes is verified by scanning electron microscopy (SEM). It can be expected that the method presented in this letter is also appropriate for the preparation of nanotubes of other semiconductors.

A large-scale crystalline silicon nanowires (SiNWs) with a diameter of ∼30 nm andlength of tens of micrometers on Al2O3 templates andsilicon wafers were synthesizedby the thermal evaporation of silicon monoxide (SiO). The SiNWs were measuredby transmission electron microscopy, scanning electron microscopy, X-ray di4raction andRaman spectroscopy, respectively. It was pointedout that the SiNWs possessedthe well crystalline structure. Therefore, it is consideredthat SiO couldbe usedas Si sources to produce larger-scale SiNWs andcrystalline SiNWs may grow from amorphous nuclei.

The extended defects in nitrogen-doped Czochralski (NCZ) silicon and conventional Czochralski (CZ) silicon during the diode process were systematically investigated by means of optical microscopy and transmission electron microscopy. It was revealed that during the phosphorous diffusion (1230 C/2 h), the dislocations and stacking faults generated simultaneously in the NCZ silicon while in the CZ silicon only dislocations were observed. After the boron diffusion (1260 C/30 h), only dislocations as the extended defects were observed in both the NCZ and CZ silicon. It is preliminarily believed that the difference between the formation of extended defects in the NCZ and CZ silicon wafers is ascribed to the effect of nitrogen on oxygen precipitation.

g at 1050℃ in a Czochralski (CZ) silicon wafer has been investigated. It has been proved that the RTP-induced vacancies only enhance the early stage oxygen precipitation at 1050℃ in terms of the precipitation rate. Furthermore, it is somewhat unexpected that after a lengthy 1050℃ anneal the oxygen precipitates generated in the CZ silicon wafer with prior RTP treatment had considerably lower density and larger sizes in comparison with those generated in the CZ silicon wafer without prior RTP treatment. The reason for this is that the prior RTP treatmentwill dissolve some of the grown-in oxygen precipitates, thus making the RTP-treated wafer possess fewer nuclei contributing to oxygen precipitation in the subsequent 1050℃ anneal. Moreover, the numbers of resulting precipitated oxygen atoms due to a lengthy 1050℃ anneal were nearly the same in the CZ silicon wafers with and without prior RTP treatment. Additionally, it has been illustrated that the high temperature RTP has superior capability to dissolve the existing oxygen precipitates. It is worthwhile to point out that, when addressing the effect of RTP on the oxygen precipitation behaviour during the subsequent anneal, two functions arising from the RTP treatment, that is, the injection of vacancies into the silicon wafer and the dissolution of grown-in oxygen precipitates existing in the silicon wafer, should be taken into account.