High optical quality AlInGaN by metalorganic chemical vapor deposition

We report on the metalorganic chemical vapor deposition of the quaternary a lloy AlInGaN. We found it desirable to grow quaternary films at temperature s greater than 855 degrees C in order to suppress deep level emissions in t he room-temperature photoluminescence. Details of the conditions necessary to grow In0.1Ga0.9N at 875 degrees C are presented. Strained and relaxed Al InGaN films were grown with good optical and structural properties for AlN compositions up to 26% and InN content up to 11%. The effects of strain wer e observed by a difference in the band gap between thin and thick films wit h the same compositions. The potential impact of the use of quaternary film s is discussed regarding strain engineering for the improvement of present device designs. (C) 1999 American Institute of Physics. [S0003-6951(99)0464 7-1].