Some of the InP LADEA Results

These first images and spectra are taken of a laser crater which was illuminated with a XeCl excimer laser at a power setting which is well above the ablation threshold for InP. This crater was then exposed to a chlorine/helium mixture. It is evident that there is a larger chlorine concentration in the crater than outside. This has been interpreted as chlorine reacting with elemental indium which was left after phosphorus depletion during ablation. The different states of indium are quite apparent in the spectra and correlate to a decreased phosphorus level.

These next images and spectra are from a crater illuminated at a power setting well below the ablation threshold while in a chlorine/helium atmosphere. One obvious difference here is that the incorporation of chlorine around the crater is much larger. This is interpreted as due to the slight heating during illumination. The chlorine was incorporated here because the chlorine/helium exposure was during illumination, while the exposure of crater A1 took place after the wafer had time to cool.