| Popis: |
TiCl 4 is a very efficient source of Ti doping for InP grown by low pressure organometallic vapor phase epitaxy (OMVPE), and we report some characteristics of the doping behavior. Precipitates are visible in the material (TEM observation) for Ti concentrations > 10 18 cm -3 , although morphological problems only appear for concentrations above 10 19 cm -3 . As reported by other authors, a delay in incorporation is seen, and attributed to the reaction of TiCl 4 with oxygen or oxygen-containing compounds adsorbed on the reactor walls. Also as reported before, we find that the level of electrical activity of Ti in InP stays low, although it is sufficient to allow the growth of semi-insulating InP:Zn + Ti or InP:Fe + Ti. TiCl 4 does not introduce Ti in AlInAs, but Ti doping of GaInAs is obtained, and can render the material highly resistive. The incorporation of Zn is seen to be influenced (slightly increased) by the introduction of Ti. |
