Interface Properties of Mixed (TiO2)1−x(Y2O3)x and (Ta2O5)1−x(Y2O3)x (0≤x≤1) Gate Dielectrics on Sulfur-Passivated GaAs
Interface Properties of Mixed (TiO2)1−x(Y2O3)x and (Ta2O5)1−x(Y2O3)x (0≤x≤1) Gate Dielectrics on Sulfur-Passivated GaAs
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DOI：
10.1149/2.094203jes
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发表时间：
2012
影响因子：
3.9
通讯作者：
T. Das;C. Mahata;S. Mallik;S. Varma;G. Sutradhar;P. K. Bose;C. Maiti
中科院分区：
文献类型：
--
作者：
T. Das;C. Mahata;S. Mallik;S. Varma;G. Sutradhar;P. K. Bose;C. Maiti
An experimental technique to reduce the growth of undesirable interface layer in high-k gate dielectrics is reported. Effects of mixing of TiO 2 and Ta 2 O 5 in Y 2 O 3 on the interface layer growth are studied in detail. Chemical composition and the interfacial properties of Y 2 O 3 (TiO 2 and Ta 2 O 5 mixed) ultra thin films prepared by RF sputtering on S-passivated GaAs are reported. It is shown that the formation of Ga-O bonding at the GaAs surface and As diffusion in the dielectric may effectively be controlled by mixing of TiO 2 and Ta 2 O 5. Band gap (E g) of the mixed (TiO 2) 1− x (Y 2 O 3) x and (Ta 2 O 5) 1− x (Y 2 O 3) x high-k gate dielectrics are found to be∼ 5.3±0.05 and∼ 5.5±0.05 eV, respectively. The Ta and Ti incorporated Y 2 O 3 [(Ta 2 O 5) 1− x (Y 2 O 3) x and (TiO 2) 1− x (Y 2 O 3) x] films on p-GaAs improve metal-oxide-semiconductor (MOS) capacitor characteristics such as interface state density, accumulation capacitance, hysteresis, and leakage current. The leakage current of∼ 2.4× 10− 6 A/cm 2 at V g= V fb− 1V was achieved for (TiO 2) 1− x (Y 2 O 3) x/GaAs gate stacks.
