Kris's Research Notes

June 21, 2011

Barriers Inside Ga Liquid

Filed under: GaAs Simulations — Kris Reyes @ 10:30 pm

We had previously discussed treating the process of an As atom diffusing inside Ga liquid as a separate process, which did not necessarily involve bond-counting to determine energy barriers for such events. In order to do this, we introduce barriers for these events. In this note, we discuss these barriers, their associated rates and how we determine when an atom in Ga liquid.


June 8, 2011

Hill Formation

Filed under: GaAs Simulations — Kris Reyes @ 9:01 pm

During our meeting, we had discussed the a potential mechanism for hill formation. The idea was that in the presence of nearby As atoms (for example, newly deposited As atoms during crystallization) the Ga atoms in the liquid Ga droplet would move to them in order to form energetically favorable Ga-As bonds. In this post, we examine results from experiments that show this is indeed the case and how hills can form as a result.


June 7, 2011

Etching without Extended Species

Filed under: GaAs Simulations — Kris Reyes @ 6:25 pm

In this post, we show how droplet etching is possible with the simplified model. Recall that this process was the issue with the old model — we found that the rates of an As atom detaching from the substrate into the droplet and the reverse process were too disparate, which meant that etching would not occur in a reasonable time scale. With the new model, the difference in rates between these two events is now a reasonable amount, allowing for droplet etching.