Title :
An ohmic contact process for AlGaN/GaN structures using TiSi2 electrodes
Author :
Okamoto, Mitsuo ; Kakushima, K. ; Kataoka, Yasuyuki ; Nishiyama, A. ; Sugii, Nobuyuki ; Wakabayashi, H. ; Tsutsui, K. ; Iwai, Hisato ; Saito, Wataru
Author_Institution :
Frontier Res. Center, Tokyo Inst. of Technol., Yokohama, Japan
Abstract :
We report an Ohmic contact process using TiSi2 electrodes for contact metals on AlGaN/GaN structures. TiSi2 films have been formed by cyclic deposition of Ti and Si layers by sputtering and annealing. Cross-sectional TEM image of the sample annealed has revealed a formation of an interfacial layer above AlGaN layer, however, no intrusion of Ti or Si atoms has been observed at dislocation. Specific contact resistance on annealing time showed gradual reduction with longer time. Therefore, TiSi2 can be a candidate as a contact material for AlGaN/GaN structures independent to dislocation density of epiwafers.
Keywords :
III-V semiconductors; aluminium compounds; annealing; contact resistance; dislocation density; electrodes; gallium compounds; high electron mobility transistors; ohmic contacts; sputter deposition; transmission electron microscopy; wide band gap semiconductors; AlGaN-GaN; AlGaN-GaN structures; TiSi2; TiSi2 electrodes; annealing; contact metals; contact resistance; cross-sectional TEM image; cyclic deposition; dislocation density; high-electron-mobility transistors; interfacial layer; ohmic contact process; sputtering; Aluminum gallium nitride; Annealing; Gallium nitride; Ohmic contacts; Silicides; Titanium compounds;
Conference_Titel :
Wide Bandgap Power Devices and Applications (WiPDA), 2013 IEEE Workshop on
Conference_Location :
Columbus, OH
DOI :
10.1109/WiPDA.2013.6695586
