Showing papers by "Junji Komeno published in 1989"
TL;DR: In this article, the authors investigated photoionization of deep traps in AlGaAs/GaAs multiple-quantum-well layers and measured the photocurrent (PC) parallel to the layers under a small electric field.
Abstract: We investigated photoionization of deep traps in AlGaAs/GaAs multiple‐quantum‐well layers and measured the photocurrent (PC) parallel to the layers under a small electric field. There is a small shoulder due to the photoionization of a deep trap on the low‐energy side of the n=1 exciton resonance peak in the PC spectra taken as a function of the excitation energy ℏω. The excitation energy dependence f(ℏω) and amplitude A of the photoionization cross section, σ(ℏω)=Af(ℏω), are determined by the time constants of single‐shot PC transients. The excitation energy dependence increases linearly with excitation energy. The photoionization threshold energy EMQWth and the amplitude A increase as well thickness decreases. These characteristics are explained well by our theoretical study on the photoionization of a deep trap to subbands.
36 citations
TL;DR: In this paper, tertiary butylarsine (tBAs) was used as a source alternative to AsH3 in the metalorganic vapor phase epitaxy (MOVPE) of selectively doped AlGaAs/GaAs heterostructures.
Abstract: We have used tertiarybutylarsine (tBAs) as a source alternative to AsH3 in the metalorganic vapor phase epitaxy (MOVPE) of selectively doped AlGaAs/GaAs heterostructures. A sheet carrier concentration of 9.2×1011 cm-2 and an electron mobility of 52000 cm2V-1s-1 have been obtained at 77 K for a heterostructure with a 5 nm spacer layer. This is, to our knowledge, the first demonstrated fabrication of two-dimensional electron gas with an alternative As source.
18 citations
TL;DR: In this article, an MOVPE technique capable of mass-producing HEMT LSI quality AlGaAs/GaAs selectively doped heterostructures by a barrel-type reactor was developed.
Abstract: We have developed an MOVPE technique capable of mass-producing HEMT LSI quality AlGaAs/GaAs selectively doped heterostructures by a barrel-type reactor. The reactor grows six three-inch wafers at a time. The uniformities of layer thickness and donor concentration are ±2.1% and ±2.0% across a three-inch wafer, respectively. The wafer-to-wafer uniformities for six wafers are ±2.3% for thickness and ±1.7% for donor concentration. The fabricated ring oscillator circuits having a quarter-micron gate showed an average delay time of 11.6 ps/gate with a standard deviation of 0.46 ps over an entire three-inch wafer.
4 citations
TL;DR: In this paper, the authors investigated photoionization of deep traps in AlGaAs/GaAs multiple-quantum-well layers and measured the photocurrent (PC) parallel to the layers under a small electric field.
Abstract: We investigated photoionization of deep traps in AlGaAs/GaAs multiple‐quantum‐well layers and measured the photocurrent (PC) parallel to the layers under a small electric field. There is a small shoulder due to the photoionization of a deep trap on the low‐energy side of the n=1 exciton resonance peak in the PC spectra taken as a function of the excitation energy ℏω. The excitation energy dependence f(ℏω) and amplitude A of the photoionization cross section, σ(ℏω)=Af(ℏω), are determined by the time constants of single‐shot PC transients. The excitation energy dependence increases linearly with excitation energy. The photoionization threshold energy EMQWth and the amplitude A increase as well thickness decreases. These characteristics are explained well by our theoretical study on the photoionization of a deep trap to subbands.
2 citations