Abstract :
This paper reports the first results on a modified molecular layer epitaxy (MLE) technique to deposit epitaxial GaAs films by changing the substrate temperature for alternate TEG (or TMG) and AsH3 injection. This method of temperature synchronized molecular layer epitaxy (TSMLE) is a new concept for MLE and atomic layer epitaxy (ALE). The growth rates and the doping phenomena showed different characteristics to the conventional methods which were performed at a constant temperature. This method was effective not only for the study of monolayer growth, but also for device application, especially for the heavily doped p-type layer of which carrier concentration is 1020 cm-3 order. Carbon doped p-type layer was achieved by TMG-AsH3 TSMLE. The carbon concentration increased by decreasing the temperature during AsH3 injection and by increasing the temperature during TMG injection. Zn-doped layer was achieved by TEG-AsH3 TSMLE using DEZn as a dopant gas for p-type layer fabrication. To doped heavily, DEZn injected after AsH3 injection and the temperature during AsH3 injection had a suitable value at 393°C.
