Fachbereich 11 - Physik
Institut für Materialphysik
Diffusion and Defects in Elementary and Compound Semiconductors

Acceptor diffusion and segregation in (AlxGa1-x ) 0.5In0.5P heterostructure

Acceptor segregation is investigated as a function of compositional difference, Dx, between adjacent layers in (Al_xGa_1-x)_0.5In_0.5P heterostructures. Magnesium, zinc, beryllium, and manganese acceptor species are all shown to segregate out of the high band gap aluminium-rich (Al_xGa_1-x)_0.5In_0.5P layers and into the low band gap aluminium-poor (Al_xGa_1-x)_0.5In_0.5P layers during high temperature epitaxial growth of the heterostructures. The observed acceptor segregation appears to be independent of growth method or dopant incorporation method (metalorganic chemical vapour deposition, gas source molecular-beam epitaxy, or ion implantation), and increases with increasing compositional difference between adjacent (Al_xGa_1-x)_0.5In_0.5P layers. A theoretical model is developed to describe acceptor segregation based on charge separation and the resulting electric field across the heterointerface. Comparison between experimentally measured and theoretically predicted acceptor segregation ratios gives excellent agreement for (AlxGa1-x)0.5In0.5P heterostructures over the range of compositional differences from Dx=0.12 to Dx=0.93.

Drittmittelgeber:

LumiLeds Lighting, San Jose, California, USA

Beteiligte Wissenschaftler:

HDoz. Dr. H. Bracht, Dr. Y.L. Chang (Agilent Technologies Laboratories, Palo Alto, California, USA), Dr. P.N. Grillot (LumiLeds Lighting, San Jose, California, USA) Dr. J.W. Huang (LumiLeds Lighting, San Jose, California, USA)

Veröffentlichungen:

P.N. Grillot, S.A. Stockman, J.-W. Huang, H. Bracht, and Y.L. Chang: Acceptor diffusion and segregation in (Al_xGa_1-x)_0.5In _0.5P heterostructures, Journal of Applied Physics 91 (2002) 4891-4899.