Laser‐induced chemical reactions at the Al/III‐V compound semiconductor interface

1986 ◽  
Vol 60 (6) ◽  
pp. 1994-2002 ◽  
Author(s):  
H. W. Richter ◽  
L. J. Brillson ◽  
M. K. Kelly ◽  
R. R. Daniels ◽  
G. Margaritondo
Keyword(s):  
Chemical Reactions ◽  
Compound Semiconductor ◽  
Semiconductor Interface

Amorphous-phase formation and initial reactions at Pt/GaAs interfaces

1991 ◽  
Vol 49 ◽  
pp. 858-859
Author(s):  
Dae-Hong Ko ◽  
Robert Sinclair
Keyword(s):  
Solid State ◽  
Amorphous Phase ◽  
Phase Formation ◽  
Compound Semiconductor ◽  
Metal Compound ◽  
Heat Of Mixing ◽  
Semiconductor Interface ◽  
Direct Demonstration ◽  
State Amorphization ◽  
Amorphous Phase Formation

It is now well known that many metals form a l-2nm amorphous interdiffused layer when deposited onto clean Si surface, which grows upon annealing in some systems but crystallizes into stable, or metastable, phases in others. Such behavior can be interpreted in terms of a solid-state amorphization, driven by a negative heat of mixing of the elements with the amorphous phase produced for kinetic reasons. Some metal/compound semiconductor systems also show the same reaction behavior. Though there have been some reports, using electron diffraction, on the amorphous phase formation at metal-compound semiconductor interface upon low temperature annealing, because the expected thickness might only be several atomic layers, it is clear that high resolution transmission electron microscopy (HRTEM) is the most powerful technique to study such a phase. This article reports on the amorphous phase formation and the initial stages of reaction occuring at Pt/GaAs interfaces upon annealing with HRTEM, and this is the most direct demonstration of solid state amorphization of a metal with a compound semiconductor.

Theimddynamically Stable Metal / III-V Compound-Semiconductor Interfaces

1985 ◽  
Vol 54 ◽  
Author(s):  
R. Stanley Williams ◽  
Jeffrey R. Lince ◽  
Thomas C. Tsai ◽  
John H. Pugh
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Compound Semiconductor ◽  
Enthalpy Change ◽  
Reaction Products ◽  
Bulk Materials ◽  
Semiconductor Interface ◽  
Group V ◽  
Semiconductor Interfaces ◽  
Higher Temperature

ABSTRACTChemical reactions that occur at a metal/III-V compound-semiconductor interface should be minimized if the change in Gibbs free energy of the bulk materials with respect to any possible reaction products is positive. However, the large positive change in entropy caused by vaporization of the highly volatile group V elements is a very important contribution to the Gibbs free energy of these systems, especially at higher temperatures. Thus, a particular metal/III-V compound-semiconductor interface may be thermody-namically stable at one temperature, but unstable with respect to sublimation of elemental group V species at a higher temperature if the enthalpy change for the reaction is positive. Examination of bulk phase diagrams makes it possible to rationalize the reaction products observed and to predict which will be the most stable interface for any particular metal/III-V system.

Alloying and entropy effects in predicting metal/compound–semiconductor interface reactivity

1987 ◽  
Vol 2 (4) ◽  
pp. 516-523 ◽  
Author(s):  
John F. McGilp
Keyword(s):  
Solid State ◽  
Thermodynamic Model ◽  
Compound Semiconductor ◽  
Solid State Reactions ◽  
Metal Compound ◽  
Alloy Formation ◽  
Semiconductor Interface ◽  
Group V ◽  
Specific Effects ◽  
Entropy Effects

A previous bulk thermodynamic model, which used enthalpies of compound and alloy formation to predict metal/compound–semiconductor interface reactivity, is extended to include entropy. It is shown that, for most metals on CdTe, GaAs, GaSe, InP, and MoS2, solid-state reactions are energetically favored up to semiconductor dissociation temperatures and, consequently, entropy effects are minimal. Gold and silver, with their small enthalpies of metal–semiconductor anion compound formation, can be exceptions. Even here, the results for gold/III–V systems favor solid-state reaction at room temperature, but at higher temperatures entropy drives the reaction via vapor-phase production of the group V element. The binary phase bulk thermodynamic model is not sufficient to predict absolute reactivity, but can rank the reactivity of the various metal–semiconductor combinations successfully, as long as possible alloy formation is included. It is suggested that the limitations of the model are due to the specific effects of the interface.

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