Low temperature etching of GaAs substrates and improved morphology of GaAs grown by metalorganic molecular beam epitaxy using trisdimethylaminoarsenic and triethylgallium

Marx, D.; Asahi, H.; Liu, X.F.; Higashiwaki, Masataka; Villaflor, A.B.; Miki, K.; Yamamoto, Kazuhiko; Gonda, S.; Shimomura, S.; Hiyamizu, S.

doi:10.1016/0022-0248(95)80271-d

Cited by 23 publications

(3 citation statements)

References 10 publications

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“…26 Further evidence for this conjecture is provided by the well-established use of the decomposition of organic complexes such as tris͑dimethylamino͒ arsenic and tris͑dimethylamino͒ antimony for the preparation of oxide-free GaAs surfaces at temperatures above 450°C. [27][28][29] These complexes begin to decompose at temperatures above 300°C, producing dimethylamine and N-methylmethyleneimine that have been shown to etch the GaAs native oxides. 30,31 The ALD reaction examined in this work produces similar amine products through either a regular hydrogen abstraction or ␤-hydride elimination pathway.…”

Section: Discussionmentioning

confidence: 99%

Growth and Interface Evolution of HfO[sub 2] Films on GaAs(100) Surfaces

Gougousi¹,

Hackley²,

Demaree³

et al. 2010

J. Electrochem. Soc.

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The initial film growth ͑2-100 cycles͒ and the interface evolution of HfO 2 thin films on GaAs surfaces were investigated for an atomic layer deposition chemistry that utilizes tetrakis͑ethylmethyl͒ amino hafnium and H 2 O at 250°C. Starting surfaces include native oxide and HF or NH 4 OH-etched substrates. X-ray photoelectron spectroscopy shows that deposition on native oxide GaAs surfaces results in the gradual consumption of the arsenic and gallium oxides. Arsenic oxides are easier to remove, leaving some metallic arsenic-arsenic suboxide at the interface. The removal of the gallium oxides is slower, and some residual Ga 2 O 3 and Ga 2 O are detected after 100 process cycles. High resolution transmission electron microscopy confirms the presence of an almost sharp interface for the 100 cycle ͑12 nm͒ film and indicates that the as-deposited film is polycrystalline. The depositions on either HF or NH 4 OH-etched substrates result in a sharp interface with very little residual gallium oxide and arsenic suboxide present. Rutherford backscattering spectroscopy shows that steady-state growth comparable to that achieved on SiO 2 is reached after ϳ20 ALD cycles for all GaAs surfaces; however, high initial surface activity is detected for the etched surfaces.The deposition of high dielectric constant ͑high-k͒ materials has been studied extensively in the past decade as a potential replacement to SiO 2 in an effort to extend the lifetime of Si-based nanoelectronic devices. One of the major obstacles encountered in the introduction of high-k materials has been the inadvertent growth of low dielectric constant interfacial layers ͑ILs͒. 1 Although the presence of ILs improves the interface properties of the gate stack, it also results in the overall reduction in the stack capacitance, negating much of the benefit afforded by the introduction of the high-k material. 2 Alternative, higher mobility substrates such as Ge and III-V-based semiconductors are well known, but their use in the microelectronics industry has been hampered by the absence of a high quality native oxide comparable to the Si/SiO 2 system. 3 However, extensive research into high-k materials has led to a renewed interest in the pairing of high mobility substrates with high-k materials in future generations of nanoelectronic devices. Although the deposition of dielectrics on Si surfaces is invariably accompanied by the formation of an IL regardless of the deposition technique, several reports demonstrate a sharp interface between the high-k and the high mobility substrate. In fact, several groups have demonstrated well-behaved devices utilizing Al 2 O 3 and HfO 2 dielectrics on Ge-, GaAs-, and InGaAs-based substrates. 4-8 When atomic layer deposition ͑ALD͒ is used for the deposition of Al 2 O 3 , TiO 2 , and HfO 2 dielectrics on GaAs and InGaAs native oxide surfaces, the thinning of these surface oxides is observed. All these observations share the common thread of the use of metallorganic precursors such as trimethyl aluminum and hafnium and titanium amides...

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Section: Discussionmentioning

confidence: 99%

Growth and Interface Evolution of HfO[sub 2] Films on GaAs(100) Surfaces

Gougousi¹,

Hackley²,

Demaree³

et al. 2010

J. Electrochem. Soc.

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“…Further supporting evidence can be found in the reports of surface oxide removal caused by the thermal decomposition of metal organic molecules such as tris dimethyl amino arsenic on GaAs surfaces. [17][18] ACKNOWLEDGMENTS…”

Section: Discussionmentioning

confidence: 99%

Atomic Layer Deposition of Metal Oxide Films on GaAs (100) surfaces

Gougousi

Lacis

Hackley³

et al. 2009

MRS Proc.

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Atomic Layer Deposition is used to deposit HfO2 and TiO2 films on GaAs (100) native oxides and etched surfaces. For the deposition of HfO2 films two different but similar ALD chemistries are used: i) tetrakis dimethyl amido hafnium (TDMAHf) and H2O at 275°C and ii) tetrakis ethylmethyl amido hafnium (TEMAHf) and H2O at 250°C. TiO2 films are deposited from tetrakis dimethyl amido titanium (TDMATi) and H2O at 200°C. Rutherford Back Scattering shows linear film growth for all processes. The film/substrate interface is examined using x-ray Photoelectron Spectroscopy and confirms the presence of an “interfacial cleaning” mechanism.

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“…Recent reports show that TDMAAs has an etching effect on GaAs. 7,8 The MBE chamber used in the present work is equipped with gas cells for supplying organic sources ͑TMGa and TD-MAAs͒ as well as effusion cells for evaporating metallic sources ͑Ga, Al, and As͒. 9 TDMAAs was introduced through a gas cracker to etch about 500 Å of the GaAs substrate surface.…”

Section: Methodsmentioning

confidence: 99%

Built-in electric fields in GaAs/GaAs structures with different in situ substrate treatments

Luyo-Alvarado¹,

Meléndez‐Lira²,

López‐López³

et al. 2001

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Improved surface treatments for recycled (100) GaAs substrates in view of molecular-beam epitaxy growth: Auger electron spectroscopy, Raman, and secondary ion mass spectrometry analyses We have prepared GaAs substrates prior to molecular beam epitaxial growth by the following in situ treatments: ͑1͒ The usual thermal cleaning under an arsenic flux, ͑2͒ cleaning by hydrogen radicals ͑H*͒, and ͑3͒ exposure to trisdimethylaminoarsine ͑TDMAAs͒. The effects of these treatments on the optical properties and built-in electric fields in GaAs/GaAs structures were studied. In order to investigate the effects of the substrate type on the properties of the GaAs epilayers, undoped semi-insulating ͑SI͒ GaAs ͑100͒ and Si-doped n ϩ -GaAs͑100͒ substrates were used. Reflection high-energy electron diffraction during the growth, and atomic force microscopy in air showed that the smoothest surface morphology was obtained for the layer grown on a H*-cleaned SI substrate at 570°C. For Si-doped substrates the smoothest layer was obtained on a TDMAAs-treated substrate. The concentrations of interfacial residual impurities of C and O were measured by secondary ion mass spectroscopy ͑SIMS͒. For SI substrates, the usual thermal cleaning process resulted in very high concentrations of C (2ϫ10 19 atoms/cm 3 ) and O (1.3ϫ10 18 atoms/cm 3 ) at the interface. The impurities were drastically diminished to below the SIMS detection limit by using H*-cleaning. We observed higher concentrations of impurities on Si-doped substrates. Internal electric fields due to the interfacial impurities were detected by the presence of Franz-Keldysh oscillations in the room temperature photoreflectance spectra. The samples with the highest amount of interfacial impurities presented the strongest internal electric fields. Photoluminescence results showed a clear correlation between the amount of interfacial impurities and signal intensity, the lower the impurity content the stronger the photoluminescence intensity. The signal associated with carbon impurities dominates the photoluminescence spectra for GaAs layers grown on SI substrates, while for samples grown on Si-doped substrates the signal coming from the substrate is the dominant one.

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Low temperature etching of GaAs substrates and improved morphology of GaAs grown by metalorganic molecular beam epitaxy using trisdimethylaminoarsenic and triethylgallium

Cited by 23 publications

References 10 publications

Growth and Interface Evolution of HfO[sub 2] Films on GaAs(100) Surfaces

Growth and Interface Evolution of HfO[sub 2] Films on GaAs(100) Surfaces

Atomic Layer Deposition of Metal Oxide Films on GaAs (100) surfaces

Built-in electric fields in GaAs/GaAs structures with different in situ substrate treatments

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