氧化鑭薄膜閘極結構與電性並應用在砷化鎵高速場效應電晶體研製

This paper investigates the feasibility of using a lanthanum oxide thin film （La2O3） with a high dielectric constant as a gate dielectric on GaAs pHEMTs to reduce gate leakage current and improve the gate to drain breakdown voltage relative to the conventional GaAs pHEMT. An E/D mode pHEMT in a single chip was realized by selecting the appropriate La2O3 thickness. The thin La2O3 film was characterized： its chemical composition and crystalline structure were determined by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. La2O3 exhibited good thermal stability after post-deposition annealing at 200, 400 and 600℃ because of its high binding-energy （835.6 eV）. Experimental results clearly demonstrated that the La2O3 thin film was thermally stable. The DC and RF characteristics of Pt/La2O3/Ti/Au gate and conventional Pt/Ti/Au gate pHEMTs were examined. The measurements indicated that the transistor with the Pt/La2O3/Ti/Au gate had a higher breakdown voltage and lower gate leakage current. Accordingly, the La2O3 thin film is a potential high-k material for use as a gate dielectric to improve electrical performance and the thermal effect in high-power applications.

Structural and electrical characteristics of lanthanum oxide gate dielectric film on GaAs pHEMT technology

This paper investigates the feasibility of using a lanthanum oxide thin film (La2O3) with a high dielec-tric constant as a gate dielectric on GaAs pHEMTs to reduce gate leakage current and improve the gate to drain breakdown voltage relative to the conventional GaAs pHEMT.An E/D mode pHEMT in a single chip was real-ized by selecting the appropriate La2O3 thickness.The thin La2O3 film was characterized:its chemical composition and crystalline structure were determined by X-ray photoelectron spectroscopy and ...