Effects of rapid thermal processing on electron traps in molecular‐beam‐epitaxial GaAs

ABSTRACTUsing deep level transient spectroscopy we have studied the variations of electron traps in molecular beam epitaxial (MBE) AlxGa1−xAs by rapid thermal processing (RTP) using halogen lamps. RTP was performed at 700, 800 and 900 °C for 6s under a SiO2 cap and a capless condition. It is found that during RTP the electron traps with the thermal activation energies of 0.89 and 0.99 eV are produced in Al0.lGa0.9As and Al0.3Ga0.7As, respectively. The thermal activation energies of these traps are close to the reported ones for the trap EL2 in AlxGaM1−xAs. Therefore, these traps are probably related to the trap EL2. In the RTP samples under a capless condition, the concentrations of the trap EL2 in AlxGa1−xAs (x=0.1, 0.3) decreases from the surface to the deeper position in MBE layers, while the depth profile of the trap EL2 in GaAs is flat. It is suggested that the origin of the trap EL2 formation in AlxGa1−xAs is different from one in GaAs.

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Production of the midgap electron trap (EL2) in molecular‐beam‐epitaxial GaAs by rapid thermal processing

Journal of Applied Physics ◽

10.1063/1.338172 ◽

1987 ◽

Vol 61 (3) ◽

pp. 1215-1217 ◽

Cited By ~ 24

Author(s):

Akio Kitagawa ◽

Akira Usami ◽

Takao Wada ◽

Yutaka Tokuda ◽

Hiroyuki Kano

Keyword(s):

Thermal Processing ◽

Molecular Beam ◽

Rapid Thermal Processing ◽

Electron Trap ◽

Epitaxial Gaas ◽

Molecular Beam Epitaxial

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Rapid-Thermal-Processing Induced Deep Level Traps and their Spatial Distribution in MBE GaAs

MRS Proceedings ◽

10.1557/proc-92-361 ◽

1987 ◽

Vol 92 ◽

Author(s):

Akio Kitagawa ◽

Yutaka Tokuda ◽

Akira Usami ◽

Takao Wada ◽

Hiroyuki kano

Keyword(s):

Thermal Processing ◽

Deep Level Transient Spectroscopy ◽

Molecular Beam ◽

Deep Level ◽

Rapid Thermal Processing ◽

Spatial Variations ◽

Molecular Beam Epitaxial ◽

Gaas Films ◽

Si Doped ◽

Transient Spectroscopy

ABSTRACTRapid thermal processing (RTP) using halogen lamps for a Si-doped molecular beam epitaxial (MBE) n-GaAs layers was investigated by deep level transient spectroscopy. RTP was performed at 700°C, 800°C and 900°C for 6 s. Two electron traps NI ( Ec-0.5-0.7eV) and EL2 (Ec - 0.82 eV) are produced by RTP at 800 and 900°C.The peculiar spatial variations of the Nl and EL2 concentration across the MBE GaAs films are observed. The larger concentrations of the trap N1 and EL2 are observed near the edge of the samples, and the minima of N1 and EL2 concentration lie between the center and the edge of the sample. It seems that these spatial variations of N1 and EL2 concentration are consistent with that of the thermal stress induced by RTP. Furthermore, the EL2 concentration near the edge of the sample is suppressed by the contact with the GaAs pieces on the edge around the sample during RTP.

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Effects of Rapid Thermal Processing on Mbe GaAs on Si

MRS Proceedings ◽

10.1557/proc-146-413 ◽

1989 ◽

Vol 146 ◽

Cited By ~ 1

Author(s):

A. Ito ◽

A. Kitagawa ◽

Y. Tokuda ◽

A. Usami ◽

H. Kano ◽

...

Keyword(s):

Thermal Processing ◽

Deep Level Transient Spectroscopy ◽

Molecular Beam ◽

Deep Level ◽

Rapid Thermal Processing ◽

Surface Region ◽

The Other ◽

Si Substrates ◽

Molecular Beam Epitaxial ◽

Transient Spectroscopy

ABSTRACTVariations of electron traps in molecular-beam-epitaxial (MBE) GaAs layers grown on Si substrates by rapid thermal processing (RTP) have been investigated with deep level transient spectroscopy (DLTS). RTP was performed at 760 – 910 °C for 9s with Si02 encapsulant. In contrast with the layer on GaAs, the traps AI(Ec – 0.65eV) and A2(Ec – 0.81eV) are observed in the layer on Si. The trap EL2h, one of the EL2 family, is produced by RTP in the layer on Si. Some GaAs surfaces were etched to prove the deeper region. In the surface region, the concentrartion of EL2h is comparable to that of EL2 produced by RTP in the layer on GaAs. On the other hand, in ∿ 1 μm below the surface, the concentration of EL2h is about ten times as large as that of EL2. It is speculated that the stress from the GaAs/Si interface enhances the production of the EL2h concentration. In addition to the EL2, the traps R1(Ec – 0.23 eV), R2(Ec – 0.40 eV), R3(Ec – 0.43eV) and R4(Ec – 0.56 eV) are produced by RTP in the GaAs grown on Si.

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