Amorphous phase formation and initial interfacial reactions in the platinum/GaAs system

Dae Hong Ko, Robert Sinclair

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We have investigated the amorphous phase formation and initial crystalline reactions at Pt/GaAs interfaces via high-resolution transmission electron microscopy (HRTEM) and in situ HRTEM. A 3-nm-thick amorphous intermixed layer consisting of three elements, platinum, gallium, and arsenic formed at the Pt/GaAs interface during the deposition of a 500-Å-thick Pt film. The interlayer grew in a planar fashion in an amorphous state upon low temperature (e.g., 200°C) annealing by a solid-state amorphization reaction. This reaction occurs with a driving force of a negative heat of mixing, and by the dominant diffusion of Pt to the GaAs substrate, which was verified by in situ HRTEM. Following the growth of the amorphous interlayer, the Pt3Ga and PtAs2 phases nucleated within the amorphous layer and grew at the Pt and GaAs sides, respectively. The relative mobility of the three constituents at the low temperature, the structure of the crystalline intermetallic compounds, and local thermodynamical equilibrium are responsible for the sequence of the crystalline phase formation. After a complete reaction at 400°C for 20 min, we observed the formation of a layered structure of PtGa/PtAs2/GaAs as the final structure. In situ HRTEM experiments also demonstrated growth of the amorphous intermixed layer and crystalline reaction between the Pt film and the GaAs, which is consistent with the results from the ex situ annealing treatment.

Original languageEnglish
Pages (from-to)2036-2042
Number of pages7
JournalJournal of Applied Physics
Volume72
Issue number5
DOIs
Publication statusPublished - 1992 Dec 1

Fingerprint

platinum
transmission electron microscopy
high resolution
interlayers
annealing
arsenic
thick films
gallium
intermetallics
solid state
heat

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

@article{c7da737bec1f4e3eb322afa4d3ef4bc8,
title = "Amorphous phase formation and initial interfacial reactions in the platinum/GaAs system",
abstract = "We have investigated the amorphous phase formation and initial crystalline reactions at Pt/GaAs interfaces via high-resolution transmission electron microscopy (HRTEM) and in situ HRTEM. A 3-nm-thick amorphous intermixed layer consisting of three elements, platinum, gallium, and arsenic formed at the Pt/GaAs interface during the deposition of a 500-{\AA}-thick Pt film. The interlayer grew in a planar fashion in an amorphous state upon low temperature (e.g., 200°C) annealing by a solid-state amorphization reaction. This reaction occurs with a driving force of a negative heat of mixing, and by the dominant diffusion of Pt to the GaAs substrate, which was verified by in situ HRTEM. Following the growth of the amorphous interlayer, the Pt3Ga and PtAs2 phases nucleated within the amorphous layer and grew at the Pt and GaAs sides, respectively. The relative mobility of the three constituents at the low temperature, the structure of the crystalline intermetallic compounds, and local thermodynamical equilibrium are responsible for the sequence of the crystalline phase formation. After a complete reaction at 400°C for 20 min, we observed the formation of a layered structure of PtGa/PtAs2/GaAs as the final structure. In situ HRTEM experiments also demonstrated growth of the amorphous intermixed layer and crystalline reaction between the Pt film and the GaAs, which is consistent with the results from the ex situ annealing treatment.",
author = "Ko, {Dae Hong} and Robert Sinclair",
year = "1992",
month = "12",
day = "1",
doi = "10.1063/1.352347",
language = "English",
volume = "72",
pages = "2036--2042",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "5",

}

Amorphous phase formation and initial interfacial reactions in the platinum/GaAs system. / Ko, Dae Hong; Sinclair, Robert.

In: Journal of Applied Physics, Vol. 72, No. 5, 01.12.1992, p. 2036-2042.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Amorphous phase formation and initial interfacial reactions in the platinum/GaAs system

AU - Ko, Dae Hong

AU - Sinclair, Robert

PY - 1992/12/1

Y1 - 1992/12/1

N2 - We have investigated the amorphous phase formation and initial crystalline reactions at Pt/GaAs interfaces via high-resolution transmission electron microscopy (HRTEM) and in situ HRTEM. A 3-nm-thick amorphous intermixed layer consisting of three elements, platinum, gallium, and arsenic formed at the Pt/GaAs interface during the deposition of a 500-Å-thick Pt film. The interlayer grew in a planar fashion in an amorphous state upon low temperature (e.g., 200°C) annealing by a solid-state amorphization reaction. This reaction occurs with a driving force of a negative heat of mixing, and by the dominant diffusion of Pt to the GaAs substrate, which was verified by in situ HRTEM. Following the growth of the amorphous interlayer, the Pt3Ga and PtAs2 phases nucleated within the amorphous layer and grew at the Pt and GaAs sides, respectively. The relative mobility of the three constituents at the low temperature, the structure of the crystalline intermetallic compounds, and local thermodynamical equilibrium are responsible for the sequence of the crystalline phase formation. After a complete reaction at 400°C for 20 min, we observed the formation of a layered structure of PtGa/PtAs2/GaAs as the final structure. In situ HRTEM experiments also demonstrated growth of the amorphous intermixed layer and crystalline reaction between the Pt film and the GaAs, which is consistent with the results from the ex situ annealing treatment.

AB - We have investigated the amorphous phase formation and initial crystalline reactions at Pt/GaAs interfaces via high-resolution transmission electron microscopy (HRTEM) and in situ HRTEM. A 3-nm-thick amorphous intermixed layer consisting of three elements, platinum, gallium, and arsenic formed at the Pt/GaAs interface during the deposition of a 500-Å-thick Pt film. The interlayer grew in a planar fashion in an amorphous state upon low temperature (e.g., 200°C) annealing by a solid-state amorphization reaction. This reaction occurs with a driving force of a negative heat of mixing, and by the dominant diffusion of Pt to the GaAs substrate, which was verified by in situ HRTEM. Following the growth of the amorphous interlayer, the Pt3Ga and PtAs2 phases nucleated within the amorphous layer and grew at the Pt and GaAs sides, respectively. The relative mobility of the three constituents at the low temperature, the structure of the crystalline intermetallic compounds, and local thermodynamical equilibrium are responsible for the sequence of the crystalline phase formation. After a complete reaction at 400°C for 20 min, we observed the formation of a layered structure of PtGa/PtAs2/GaAs as the final structure. In situ HRTEM experiments also demonstrated growth of the amorphous intermixed layer and crystalline reaction between the Pt film and the GaAs, which is consistent with the results from the ex situ annealing treatment.

UR - http://www.scopus.com/inward/record.url?scp=0038301685&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038301685&partnerID=8YFLogxK

U2 - 10.1063/1.352347

DO - 10.1063/1.352347

M3 - Article

AN - SCOPUS:0038301685

VL - 72

SP - 2036

EP - 2042

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 5

ER -