Phenomenological modeling of diffusion profiles: Sn in GaAs

Abstract

A phenomenological methodology has been used to characterize the intrinsic diffusion of tin in GaAs based on the coupled motion of substitutional and interstitial Sn atoms. Both the rapid diffusivity of interstitial Sn atoms and their transformation to substitutionals by occupying gallium vacancies are processes that lead to an anomalous “double-profile” diffusion curve observed in highly doped samples. The model was developed for samples annealed over a range of 973–1123K. The model developed while developed and perhaps only applicable over this temperature range may be extendable to a larger temperature range provided that the underlying mechanism is unchanged. The methodology consists of using key aspects of the diffusion profiles along with the mass conservation criterion to predetermine bounds which prescribe the values of the parameters used to model the experimental data. This fitting procedure allowed for a more rapid assessment of the model parameters by providing physical bounds on their values as derived from the experimental profiles. The proposed diffusion mechanism combines the simultaneous diffusion of both interstitial and substitutional Sn atoms as well as key defect reactions characterizing their mutual equilibrium with the background vacancy concentration.

The effect of a material growth technique on ion-implanted Mn diffusion in GaAs

“…The observed 'double-profile' curves have been noted also in the migration of several other impurity atoms in GaAs, e.g. Sn [19,20], S [21], Cr [22] and Zn [23]. The two-component profiles obtained by Seltzer [5] for Mn are in qualitative agreement with the present findings; the studies of Wu et al [2,6] claim existence of even three components in the Mn profiles.…”

A thermodynamic approach of self- and hetero-diffusion in GaAs: connecting point defect parameters with bulk properties

“…Furthermore, this discrepancy is also due to the approach of the attempt frequency with the Debye frequency as well as the approximated values of the parameters f and g that were used in Eq. (18). Alternatively, we propose that reliable values of activation entropy may be derived according to Eq.…”

“…9 Previous studies provided fundamental insights into the diffusion and other defect processes of III-V semiconductors. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Gallium diffusion dominates self-diffusion in GaAs. 16 The diffusion of various n-and p-type dopants in GaAs has been extensively investigated in the past.…”

“…16 The diffusion of various n-and p-type dopants in GaAs has been extensively investigated in the past. [13][14][15][16][17][18][19][20][21][22][23][24][25] Silicon is a commonly used n-type dopant, 6 that although is amphoteric (it can occupy both the Ga and As sites) in As-rich grown GaAs Si is an n-type dopant occupying the Ga site. Regarding acceptor doping, Beryllium and Zinc are significant p-type dopants in GaAs with high diffusion coefficients.…”

Connecting point defect parameters with bulk properties to describe diffusion in solids

“…76 There are several investigations focusing on the diffusion of n-and p-type dopants in GaAs. [77][78][79][80][81][82][83][84] In GaAs, Si is a common n-type dopant when occupying the Ga Site (i.e., in As-rich growth conditions), 75 whereas Beryllium (Be) and Zinc (Zn) are the important ptype dopants. 79…”