Inductively-coupled Reactive Ion Etching Research Articles

Controlled synthesis of few layer graphene films for gas sensor applications

ABSTRACTA novel approach for synthesis of few layer graphene films on SiC has been developed which uses halogen based inductively coupled-reactive ion etching (ICP-RIE) and rapid thermal annealing (RTA) in atmospheric pressure argon. These films have been characterized using x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Surface characterization by XPS reveals the presence of defects similar to those observed for graphene oxide (GO) but at a much lower levels that those observed for GO. As in the case for GO, the defect density could be further reduced by chemical methods which improved carbon to defect ratio based on XPS analyses. Raman spectroscopy showed the presence of D, G and 2D peaks at 1330 cm-1, 1599 cm-1 and 2671 cm-1, respectively, which is comparable with similar graphene films formed by thermal annealing of SiC. The full widths at half max (FWHM) for these peaks was, however, comparable to those observed for GO. Electrical characterization of these graphene films using collinear four point probe measurements showed the electrical resistivity of these films is consistent with the observed values for few layer exfoliated graphene. Gas sensor structures were fabricated using lithography free methods, and initial gas response studies were performed for H2.

Influence of black silicon surfaces on the performance of back-contacted back silicon heterojunction solar cells.

The influence of different black silicon (b-Si) front side textures prepared by inductively coupled reactive ion etching (ICP-RIE) on the performance of back-contacted back silicon heterojunction (BCB-SHJ) solar cells is investigated in detail regarding their optical performance, black silicon surface passivation and internal quantum efficiency. Under optimized conditions the effective minority carrier lifetime measured on black silicon surfaces passivated with Al(2)O(3) can be higher than lifetimes measured for the SiO(2)/SiN(x) passivation stack used in the reference cells with standard KOH textures. However, to outperform the electrical current of silicon back-contact cells, the black silicon back-contact cell process needs to be optimized with aspect to chemical and thermal stability of the used dielectric layer combination on the cell.

Halogen Based Surface Chemistries for Graphene Synthesis

AbstractHalogen based (CF4 and Cl2) inductively coupled reactive ion etching (ICP-RIE) has been used to selectively etch silicon from 6H-SiC to produce a controlled number of carbon layers. After annealing at temperatures in the range of 550 °C to 1100 °C to reconstruct the near surface layers, x-ray photoelectron spectroscopy has been used to characterize the composition of the films. For the Cl2 based ICP-RIE, two carbon species are observed. One is due to carbon bound as SiC in the substrate and a second which can be attributed to graphene. In the case of CF4 based etching the situation is similar except the second peak is most closely aligned with p-type graphene. This is most likely due to electron transfer from the graphene to the trace levels of fluorine remaining on the surface after annealing.