Epitaxial Growth And Mechanism Analysis Of InGaAsN Film Grown On GaAs Substrate By MBE

Due to the giant band-gap bowing, In Ga As N alloys with a few percent nitrogen(N) have shown significant promise for extensive applications including long-wavelength laser diodes, near infrared photodetectors and thin film solar cells. So the deposition of dilute nitride In Ga As N on Ga As substrate has received great attention in the past few years. The unique advantage of this dilute nitride is the adjustability both for the lattice constant and the bandgap, allowing lattice of this material to match with Ga As or Ge over a wide range of band-gap. However, the variables that required to control during the epitaxial growth of In Ga As N are so many that the growth mechanism has not been fully comprehended. In term of the measurements on growth technics, particularly for the growth temperature, beam ratio and growth rate et al. are relatively insufficient. Besides, analysis on behaviors of atomic adsorption and migration are also deficient, leading to a relative imperfection system.In this paper, we have prepared In Ga As N films on Ga As substrates by MBE method. The crystal structure, surface morphology, elemental incorporation and electrical performance parameters which are the most important criterions in film evaluation are our primary concernes. Based on the experimental test results, we have explored the effects of epitaxial face of Ga As substrate, As/III beam ratio, growth temperature, operating parameter of radio frequency(RF) source as well as the growth rate on the In Ga As N epitaxial growth characteristics. Accordingly, we make a detail discussion on the In behavior of incorporation and migration, and summary a series of optimized parameters in growing In Ga As N films.To fully understand the growth mechanism of In Ga As N film on Ga As substrate, we have carried out computer simulations that consistent with the experimental results so as to study the N behavior of adsorption, desorption, diffusion and interaction with other atoms. Furthermore, we use DFT calculation method to study the band structrure and the electronic distribution of In Ga As N, which provides explanation to the low mobility of carrier.