Analyses of hetero-interface trapping properties in AlGaN/GaN high electron mobility transistor heterostructures grown on silicon with thick buffer layers

作者：Freedsman Joseph J^*; Kubo Toshiharu; Egawa Takashi

来源：Applied Physics Letters, 2012, 101(1): 013506.

DOI：10.1063/1.4733359

• aluminium compounds
• buffer layers
• dislocation density
• edge dislocations
• gallium compounds
• high electron mobility transistors
• III-V semiconductors
• MOCVD
• semiconductor growth
• wide band gap semiconductors

We report on the analyses of trapping properties of metal-organic chemical vapor deposition grown AlGaN/GaN high-electron-mobility transistor (HEMT) heterostructures on silicon with increasing buffer thickness (T-buff). An exact exponential dependence of AlGaN/GaN hetero-interface trap time constants with gate bias was observed in the vicinity of threshold voltage. A low hetero-interface state density (D-it) value of similar to 2.5 x 10(10) cm(-2) eV(-1) was achieved for heterostructures grown by using thick T-buff similar to 5 mu m against a D-it value of similar to 1 x 10(11) cm(-2) eV(-1) for a similar heterostructures grown with thin T-buff similar to 1.25 mu m. Further, the high resolution x-ray rocking curve and Van der Pauw-Hall measurements also confirmed that increasing the T-buff improves the AlGaN/GaN HEMT heterostructures with reduced edge dislocation densities and enhanced carrier transport properties.

• 出版日期2012-7-2