Growth of   strained layer superlattices by MOVPE III. Use of UV absorption to monitor alkyl stability in the reactor

Booker, G. R.; Daly, Morgan; Klipstein, P. C.; Lakrimi, M.; Kuech, T. F.; Li, Jiang; Lyapin, S. G.; Mason, Nigel J.; Murgatroyd, I. J.; Portal, J. C.; Nicholas, R. J.; Symons, D.M.; Vicente, P.; Walker, P.J.

doi:10.1016/s0022-0248(96)00578-7

Cited by 22 publications

(11 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 Si-doped (111) oriented GaAs substrates were used and the growth temperature was 520°C and the growth rate was typically about 10 Å / sec. Initially a buffer layer of about 1 m of GaAs was grown on the substrate and this was followed by a layer of GaSb whose thickness was controlled by the growth time that varied between about 5 and 300 sec.…”

Section: Experimental Techniquesmentioning

confidence: 99%

Structure of GaSb layers grown on (111) GaAs surfaces

Babkevich¹,

Cowley²,

Mason³

et al. 2004

Journal of Applied Physics

View full text Add to dashboard Cite

The structure of GaSb layers with thicknesses of 70Å, 160Å, and 1260Å grown on GaAs (111) substrates by metal-organic vapor phase epitaxy has been studied by high-resolution x-ray diffraction. The lattice mismatch between the layer and the substrate is large and most of the misfit strain is taken up by a regular network of dislocations localized at the interface between the GaSb and the GaAs. The spacing between the dislocations is about 49Å along the [1¯1¯2] direction. We observe that the layers have both the ABC… and ACB… face-centered-cubic (fcc) domains with a domain size of about 1500Å. The presence of approximately the same volume of both the domains in the overall layer suggests that the particular domain is chosen largely randomly and independent of the orientation of the substrate. In contrast, the results show that the structure of the GaAs substrate was a single fcc domain. The widths of the off-axis Bragg reflections along the [111] direction for the thinnest sample was within error the same as those for the (hhh) Bragg reflections showing that each fcc domain penetrated through the entire layer.

show abstract

Section: Experimental Techniquesmentioning

confidence: 99%

Structure of GaSb layers grown on (111) GaAs surfaces

Babkevich¹,

Cowley²,

Mason³

et al. 2004

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…A variety of optical techniques exist for probing OMVPE growth, each sensitive to different parameters of interest [45,[48][49][50][51][52][53][54][55][56][57]. Fourier transform infrared spectroscopy (FTIR) [45] and ultraviolet spectroscopy [48,49] were used to monitor the gas phase concentration of precursors. FTIR showed that TTBAl was contaminated with isobutane and isobutene, and that the bubbler had to be purged for hours to dilute these gaseous impurities.…”

Section: In-situ Diagnosticsmentioning

confidence: 99%

Progress and Continuing Challenges in GaSb-based III-V Alloys and Heterostructures Grown by Organometallic Vapor Phase Epitaxy

2004

View full text Add to dashboard Cite

This paper discusses progress in the preparation of mid-IR GaSb-based III-V materials grown by organometallic vapor phase epitaxy (OMVPE). The growth of these materials is complex, and fundamental and practical issues associated with their growth are outlined. Approaches that have been explored to further improve the properties and performance are briefly reviewed.Recent materials and device results on GaInAsSb bulk layers and GaInAsSb/AlGaAsSb heterostructures, grown lattice matched to GaSb, are presented. State-of-the-art GaInAsSb materials and thermophotovoltaic devices have been achieved. This progress establishes the high potential of OMVPE for mid-IR GaSb-based devices. 2 IntroductionGaSb-based III-V semiconductor alloys are attractive for optoelectronic devices such as midinfrared lasers, detectors, and thermophotovoltaics (TPVs); and electronic devices such as highspeed transistors and resonant-tunneling diodes [1]. Alloys of particular interest are based on the binaries GaSb, AlSb, InSb, GaAs, AlAs, and InAs. As shown in Fig. 1 GaSb-based heterostructures have been successfully grown by all of the major epitaxial techniques, including liquid phase epitaxy, molecular beam epitaxy (MBE), and organometallic vapor phase epitaxy (OMVPE). While each of these technologies must contend with numerous challenges that are specific to the method of choice, several fundamental issues related to Sbcontaining III-V alloys exist. These include the low volatility of Sb compared to P-and Asbased alloys, which necessitates stringent control of V/III ratio; the requirement to use low growth temperatures (450 to 600 °C); the existence of a large solid phase miscibility gap for many Sb-containing alloys; and the affinity of AlSb-based alloys to incorporate O and C. As a consequence, growth of Sb-based alloys differs significantly from the more conventional As-and P-based materials, which certainly has made the development of the GaSb-based materials and devices very challenging.This paper discusses both the fundamental and practical issues associated with the growth of mid-IR GaSb-based III-V alloys grown by OMVPE, and briefly reviews approaches that have been explored to further improve the properties and performance of bulk layers as well as heterostructures. Growth considerations include the importance of suitable organometallic precursors and control of V/III ratio; miscibility gaps in ternary and quaternary alloys; C and O contamination in AlSb-based alloys; in-situ monitoring; GaSb substrate quality and preparation;and heterostructure growth. Recent materials and device results are limited to GaInAsSb and 3 AlGaAsSb alloys grown lattice matched to GaSb, since two comprehensive reviews on OMVPE growth of Sb-based materials were recently published [5,6]. Growth considerations and brief review of previous work Fundamental differences between Sb-based and P-or As-based III-V alloysOne of the early premises of OMVPE growth of III-V semiconductors was the utilization of precursors based on group III organometallics a...

show abstract

“…Such precursors are often delivered using a carrier gas that is passed through either a bubbler, i.e., a vessel with a dip tube, or a vapor draw ampoule, i.e., a vessel with no dip tube in which the gas-in and gas-out ports open directly into the ampoule headspace. A lack of adequate control can result in an irreproducible amount of entrained precursor, and the negative impacts of such variations on film and device properties have been widely reported [1][2][3][4][5][6][7][8][9][10]. Several factors can contribute to an inadequate level of control, including the design of the gas manifold [5,7,8,11], the design of the ampoule temperature-control system [12], the gas flow path in the ampoule [13][14][15], evaporative/sublimative cooling of the precursor in the ampoule [16,17], and the changing surface area of solid precursors in the ampoule 2 https://doi.org/10.6028/jres.124.005 (due to sublimation and subsequent recrystallization) [14,15,18].…”

Section: Introductionmentioning

confidence: 99%

“…up and P down . The Hagen-Poiseuille equation assumes(1) an ideal gas where(2) flow is laminar and (3) fully developed with (4) zero wall velocity. Assumptions (1),(2), and (4) are generally valid, since carrier gas flow is in the continuum-flow regime and is laminar and incompressible for typical conditions employed in this work, particularly near CDG2.…”

mentioning

confidence: 99%

Apparatus for Characterizing Gas-Phase Chemical Precursor Delivery for Thin Film Deposition Processes

Maslar

Kimes

Sperling

2019

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

Thin film vapor deposition processes, e.g., chemical vapor deposition, are widely used in high-volume manufacturing of electronic and optoelectronic devices. Ensuring desired film properties and maximizing process yields require control of the chemical precursor flux to the deposition surface. However, achieving the desired control can be difficult due to numerous factors, including delivery system design, ampoule configuration, and precursor properties. This report describes an apparatus designed to investigate such factors. The apparatus simulates a single precursor delivery line, e.g., in a chemical vapor deposition tool, with flow control, pressure monitoring, and a precursor-containing ampoule. It also incorporates an optical flow cell downstream of the ampoule to permit optical measurements of precursor density in the gas stream. From such measurements, the precursor flow rate can be determined, and, for selected conditions, the precursor partial pressure in the headspace can be estimated. These capabilities permit this apparatus to be used for investigating a variety of factors that affect delivery processes. The methods of determining the pressure to (1) calculate the precursor flow rate and (2) estimate the headspace pressure are discussed, as are some of the errors associated with these methods. While this apparatus can be used under a variety of conditions and configurations relevant to deposition processes, the emphasis here is on low-volatility precursors that are delivered at total pressures less than about 13 kPa downstream of the ampoule. An important goal of this work is to provide data that could facilitate both deposition process optimization and ampoule design refinement.

show abstract

Growth of strained layer superlattices by MOVPE III. Use of UV absorption to monitor alkyl stability in the reactor

Cited by 22 publications

References 12 publications

Structure of GaSb layers grown on (111) GaAs surfaces

Structure of GaSb layers grown on (111) GaAs surfaces

Progress and Continuing Challenges in GaSb-based III-V Alloys and Heterostructures Grown by Organometallic Vapor Phase Epitaxy

Apparatus for Characterizing Gas-Phase Chemical Precursor Delivery for Thin Film Deposition Processes

Contact Info

Product

Resources

About