Although this expression is derived for

an a-Si1-x C x alloy system, it is believed to be valid for Si-QDSL with an a-SiC matrix, which can be considered as an approximately homogeneous material, since the dangling bond defect density in Si-QDs is much lower than Bcl-2 inhibitor that of the a-SiC matrix, and the dangling bonds on Si-QD surfaces are passivated by the a-SiC matrix. An average composition ratio of 0.40 was used. N Total-DB, N Si-DB, and N C-DB for several treatment temperatures are shown in Figure 3. Post-HPT, Si-QDSL defect density (1.1 × 1019 cm-3) clearly reduced compared with the defect density before HPT. The defect density for 200°C treatment is still high because hydrogen diffusion is insufficient. Hydrogen intrusion depth for 60-min HPT can be estimated to be below 100 nm, and a several dangling bonds remain in the deep area of the film. The defect density for 300°C treatment is lower than that at 200°C. A large amount of hydrogen reaches the interface of the film and substrate during the 60-min HPT. The measured g value in this sample was 2.00275, which is quite similar to the g value of C-DB, meaning that N Si-DB is less than N C-DB.

Based on Equation 5, N Si-DB is estimated to be 2.2 × 1016 cm-3, indicating that Si-DBs can be efficiently passivated by the incorporated hydrogen. For the 400°C treatment, defect density decreases to 3.7 × 1017 cm-3, which is comparable with the defect density of an a-SiC film. The g value for 400°C treatment was higher than that for 300°C treatment, indicating that C-DBs – which are dominant in the total-DBs – significantly decrease despite selleck kinase inhibitor the increment in Si-DBs. For the 500°C treatment, defect density increases despite efficient hydrogen incorporation in the Si-QDSL, showing that the

hydrogen atoms are thermally activated from the Si-H bond state to the interstitial state above 300°C and from the C-H bond state to the interstitial state above 400°C. These temperatures mostly correspond to the temperatures of dehydrogenation from Si-H bonds and C-H bonds, which are approximately above 300°C [26] and 450°C to 550°C [27], respectively. In the 500°C treatment sample, a large amount of hydrogen Epothilone B (EPO906, Patupilone) atoms were in the interstitial sites; they did not contribute to the passivation of the dangling bonds. Figure 3 Spin densities of Si-QDSLs after a 60-min HPT. Figure 4 shows the Raman spectra of the Si-QDSLs after 60-min HPT at different temperatures. The peak found between 2,000 and 2,100 cm-1 corresponds to the Raman shift originating from the stretching mode of Si-H n bonds. The intensity of the peak from Si-H n bonds gradually weakens as the treatment temperature increases, indicating that the Si-H n bonds decomposed by the thermal activation of terminal hydrogen atoms. This trend agrees with the increment of N Si-DB. Figure 4 Raman spectra of Si-QDSLs after a 60-min HPT.