TY - JOUR
T1 - Electrical characteristics of passivated Pseudomorphic HEMTs with P2S5/(NH4)2SX pretreatment
AU - Chiu, Hsien Chin
AU - Huang, Yuan Chang
AU - Chen, Chung Wen
AU - Chang, Liann Be
PY - 2008/3
Y1 - 2008/3
N2 - This paper elucidates the dc, pulse I-V, microwave, flicker noise, and power properties of AlGaAs/InGaAs pseudomorphic high electron mobility transistors (pHEMTs) after various ex situ sulfur pretreatments. The pHEMTs were pretreated with NH4OH, (NH4)2SX, and 2S5 /(NH4)2SX solutions before SiO2 passivation to reduce the GaAs native oxide-related surface states. Stable phosphorus oxides and sulfur bound to the Ga and As species can be efficiently obtained using P2S5/ (NH4)2SX pretreatment; therefore, the leakage current in pHEMT was reduced following this process. Atomic force microscopy measurements indicated that the phosphorus oxides formed by P2S5/(NH4)2SX treatment also provided a better surface roughness than obtained following traditional (NH4)2SX-only pretreatment, reducing mobility degradation after sulfur pretreatment. Based on the dc and 1 μs pulse I-V measurement results, P2S5/(NH4)2SX- treated pHEMT exhibited very similar Ids trends, especially at high currents; however,NH4OH, (NH4)2 SX treatments clearly reduced the current upon pulse measurement because of the presence of surface traps. Hence, this novel pretreatment method has great potential for highly linear microwave power transistor applications.
AB - This paper elucidates the dc, pulse I-V, microwave, flicker noise, and power properties of AlGaAs/InGaAs pseudomorphic high electron mobility transistors (pHEMTs) after various ex situ sulfur pretreatments. The pHEMTs were pretreated with NH4OH, (NH4)2SX, and 2S5 /(NH4)2SX solutions before SiO2 passivation to reduce the GaAs native oxide-related surface states. Stable phosphorus oxides and sulfur bound to the Ga and As species can be efficiently obtained using P2S5/ (NH4)2SX pretreatment; therefore, the leakage current in pHEMT was reduced following this process. Atomic force microscopy measurements indicated that the phosphorus oxides formed by P2S5/(NH4)2SX treatment also provided a better surface roughness than obtained following traditional (NH4)2SX-only pretreatment, reducing mobility degradation after sulfur pretreatment. Based on the dc and 1 μs pulse I-V measurement results, P2S5/(NH4)2SX- treated pHEMT exhibited very similar Ids trends, especially at high currents; however,NH4OH, (NH4)2 SX treatments clearly reduced the current upon pulse measurement because of the presence of surface traps. Hence, this novel pretreatment method has great potential for highly linear microwave power transistor applications.
KW - Linearity
KW - Passivation
KW - Power
KW - Pseudomorphic high electron mobility transistor (pHEMT)
KW - Sulfur
UR - http://www.scopus.com/inward/record.url?scp=40949107358&partnerID=8YFLogxK
U2 - 10.1109/TED.2007.915386
DO - 10.1109/TED.2007.915386
M3 - 文章
AN - SCOPUS:40949107358
SN - 0018-9383
VL - 55
SP - 721
EP - 726
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
IS - 3
ER -