Carrier lifetime versus anneal in low temperature growth GaAs

The photoexcited carrier lifetimes in ex situ‐annealed low temperature growth GaAs are measured with a femtosecond transient absorption experiment. The study encompassed two low temperature growth GaAs films with approximately 0.3% and 0.9% excess arsenic incorporated during growth. The observed lifetimes are found to be a function of the spacing of arsenic precipitates formed during the 30 s anneals to temperatures between 650 and 1000 °C. The carrier lifetime for unannealed films was found to be less than ∼200 fs. The carrier lifetimes increased from ∼2 to ∼10 ps as the average precipitate spacing was increased from ∼400 to ∼900 A. These results are in sharp contrast to recent reports of subpicosecond lifetimes in similar GaAs annealed at 600 °C.

[1]  M. Melloch,et al.  Incorporation of Excess Arsenic in GaAs and AlGaAs Epilayers Grown at Low Substrate Temperatures by Molecular Beam Epitaxy , 1991 .

[2]  M. Melloch,et al.  1.3- mu m P-i-N photodetector using GaAs with As precipitates (GaAs:As) , 1991, IEEE Electron Device Letters.

[3]  Michael R. Melloch,et al.  Substrate temperature dependence of arsenic precipitate formation in AlGaAs and GaAs , 1991 .

[4]  Fuad E. Doany,et al.  Carrier Lifetime vs. Ion-Implantation Dose in Silicon on Sapphire , 1987, Topical Meeting on Picosecond Electronics and Optoelectronics.

[5]  J. Whitaker,et al.  Ultrafast carrier dynamics in III-V semiconductors grown by molecular-beam epitaxy at very low substrate temperatures , 1992 .

[6]  Michael R. Melloch,et al.  Subpicosecond, freely propagating electromagnetic pulse generation and detection using GaAs:As epilayers , 1991 .

[7]  M. Manfra,et al.  New MBE buffer used to eliminate backgating in GaAs MESFETs , 1988, IEEE Electron Device Letters.

[8]  E. Yablonovitch,et al.  Extreme selectivity in the lift‐off of epitaxial GaAs films , 1987 .

[9]  Frank Stern,et al.  Photon recycling in semiconductor lasers , 1974 .

[10]  Michael R. Melloch,et al.  Arsenic precipitates and the semi‐insulating properties of GaAs buffer layers grown by low‐temperature molecular beam epitaxy , 1990 .

[11]  J. Kuhl,et al.  Subpicosecond carrier trapping in high-defect-density amorphous Si and GaAs , 1984 .

[12]  E. Yablonovitch,et al.  Van der Waals bonding of GaAs epitaxial liftoff films onto arbitrary substrates , 1990 .

[13]  D. Nolte,et al.  Enhanced electro‐optic properties of low‐temperature‐growth GaAs and AlGaAs , 1993 .

[14]  Michael R. Melloch,et al.  Formation of arsenic precipitates in GaAs buffer layers grown by molecular beam epitaxy at low substrate temperatures , 1990 .

[15]  Eicke R. Weber,et al.  Stoichiometry‐related defects in GaAs grown by molecular‐beam epitaxy at low temperatures , 1989 .

[16]  D. Nolte,et al.  Arsenic cluster engineering for excitonic electro‐optics , 1993 .

[17]  Gerard Mourou,et al.  Subpicosecond carrier lifetime in GaAs grown by molecular beam epitaxy at low temperatures , 1991 .

[18]  Evans,et al.  Anomalous Hall-effect results in low-temperature molecular-beam-epitaxial GaAs: Hopping in a dense EL2-like band. , 1990, Physical review. B, Condensed matter.