Dependence of Nei to As source flow rates

The objective of this experiment is to clarify whether the density of E1 is sensitive to the As atom or not. The MMHy was supplied to 9.0 sccm and the TDMAAs was varied between and 0.7 and 1.5 sccm. As shown in Fig. 6. (a), increasing TDMMAs drops the N concentration in the film and tends to saturate for a flow rate higher than 1 sccm. For two emission rate erw = {100, 10} s-1 and filling pulse tp = {0.1, 5} ms values, the DLTS spectra are normalized on the junction capacitance to exclude the effect of various carrier densities in the samples. The same N-related recombination center E1 was observed in all samples. The TDMAAs flow rate dependence of the DLTS peak height of E1 for two settings of measurement parameters is given in Fig. 6(b). A peaking behavior at approximately TDMAAs = 0.9 sccm was obtained. As NE1 is uniformly distributed in GaAsN films, the incorporation of N atom at the growth surface affects both the incorporation of NAs and the formation of E1. If E1 depends only on N atom, the decrease of [N] with increasing TDMMAs flow rate results in monotonically dropping of NE1. However, the peaking behavior of NE1 indicates the sensitivity of E1 to As atom, either than N.

0.8 ‘ 10 ‘ 12 ‘ 14

TDMAAs (sccm)


Fig. 6. TDMAAs flow rate dependence of (a) N concentration under supplied MMHy and (b) normalized DLTS peak height of E1 for two settings of measurement parameters.

Updated: August 24, 2015 — 12:57 pm