Detailed characterization of deep level defects in InGaN Schottky diodes by optical and thermal deep level spectroscopies


Gur E. , ZHANG Z., KRISHNAMOORTY S., RAJAN S., RINGEL S. A.

APPLIED PHYSICS LETTERS, vol.99, no.9, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 99 Issue: 9
  • Publication Date: 2011
  • Doi Number: 10.1063/1.3631678
  • Title of Journal : APPLIED PHYSICS LETTERS

Abstract

Schottky diode properties of semitransparent Ag(4 nm)/Au(4 nm) metal stack on In(0.2)Ga(0.8)N were investigated and defect characterization was performed using capacitance deep level transient (DLTS) and optical spectroscopy (DLOS). DLTS measurements made on the In0.2Ga0.8N Schottky diodes, which displayed a barrier height of 0.66 eV, revealed the presence of two deep levels located at Ec-0.39 eV and Ec-0.89 eV with nearly identical concentrations of similar to 1.2 x 10(15) cm(-3). Three deeper defect levels were observed by DLOS at Ec-1.45 eV, Ec-1.76 eV, and Ec-2.50 eV with concentrations of 1.3 x 10(15) cm(-3), 3.2 x 10(15) cm(-3), and 6.1 x 10(16) cm(-3), respectively. The latter, with its high trap concentration and energy position lying 0.4 eV above the valance band, suggests a possible role in compensation of carrier concentration, whereas the mid-gap positions of the other two levels imply that they will be important recombination-generation centers (C) 2011 American Institute of Physics. [doi:10.1063/1.3631678]