Browsing by Author "Pilkuhn, M. H."

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High-speed GaAs metal gate semiconductor field effect transistor structure grown on a composite Ge/Ge(x)Si(1-x)/Si substrate
(2007-04-15)
Luo, Guang-Li
;
Hsieh, Yen-Chang
;
Chang, Edward Yi
;
Pilkuhn, M. H.
;
Chien, Chao-Hsin
In this study we used a low-pressure metal organic vapor phase epitaxy method to investigate the growth of GaAs metal gate semiconductor field effect transistor (MESFET) structures on a Si substrate. The buffer layer between the Si substrate and the grown GaAs epitaxial layers was a composite Ge/Si(0.05)Ge(0.95)/Si(0.1)Ge(0.9) metamorphic layer. We used transmission electron microscopy to observe the microstructures formed in the grown GaAs/Ge/Si(x)Ge(1-x)/Si material and atomic force microscopy to analyze the surface morphology and the formation of antiphase domains in the GaAs epitaxial layers. The measured Hall electron mobility in the channel layer of a MESFET structure grown on a 6 degrees misoriented Si substrate was 2015 cm(2) V(-1) s(-1) with a carrier concentration of 5.0x10(17) cm(-3). The MESFET device fabricated on this sample exhibited good current-voltage characteristics.
Use of Si+ pre-ion-implantation on Si substrate to enhance the strain relaxation of the GexSi1-x metamorphic buffer layer for the growth of Ge layer on Si substrate
(2007-02-19)
Hsieh, Y. C.
;
Chang, E. Y.
;
Luo, G. L.
;
Pilkuhn, M. H.
;
Tang, S. S.
Si+ pre-ion-implantation combined with a GexSi1-x metamorphic buffer structure for the growth of Ge layer on Si substrate is proposed. Enhanced strain relaxation of the GexSi1-x metamorphic buffer layer on Si substrate was achieved due to the introduction of the point defects by heavy dose Si+ pre-ion-implantation. Because of the strain relaxation enhancement and the interface blocking of the dislocations in the GexSi1-x metamorphic buffer structure, the total thickness of the buffer layers was only 0.45 mu m. No cross-hatch pattern was observed on the Ge surface and the dislocation density for the top Ge film was only 7.6x10(6) cm(-2). (c) 2007 American Institute of Physics.