Diffusion and solubility of copper in germanium

Abstract

Diffusion profiles and the solubility of Cu in Ge were measured in the temperature interval 850–1200 K by means of the spreading-resistance technique. From these data it is concluded that the diffusion of Cu in Ge involves the interchange between a highly mobile interstitial configuration, Cui, and a practically immobile substitutional configuration, Cus, with the aid of vacancies, V, via the so-called dissociative mechanism, Cui+V⇄Cus. The excellent agreement of the values of the vacancy contribution to the tracer self-diffusion coefficient in Ge, as calculated from our diffusivity and solubility data on Cu in Ge, with directly measured values of the 71Ge tracer self-diffusion coefficient from the literature demonstrates that self-diffusion in Ge occurs via vacancies. A comparison with the mechanisms of Au and self-diffusion in Si is presented.

Diffusion of silicon in crystalline germanium

“…6,9 Additionally, Werner, et al, studied the effect of hydrostatic pressure on self-diffusion and deduced an activation volume smaller than one atomic volume for the defect mediating Ge diffusion. The results of doping and hydrostatic pressure on self-diffusion as well as the excellent agreement between the Ge self-diffusion coefficient and the contribution of vacancies to self-diffusion deduced from Cu diffusion in Ge, 10,11 provide strong evidence that Ge selfdiffusion is mediated by vacancies in neutral and singly negative charge states.…”

Diffusion ofn-type dopants in germanium

“…22 The excellent agreement between Ge self-diffusion and the V contribution to selfdiffusion deduced from copper diffusion in dislocation-free Ge proved the dominance of V in Ge. [52][53][54] More recently, experiments on self-diffusion in Ge have been extended to lower temperatures 14 to verify whether the dominant mechanism of self-diffusion changes as in the case of Si. [55][56][57] Utilizing isotopically modulated 70 Ge/ nat Ge multilayer structures, the diffusional intermixing at the 70 Ge/ nat Ge interface was detected down to 429 C by means of neutron reflectometry.…”

Direct estimation of capture cross sections in the presence of slow capture: application to the identification of quenched-in deep-level defects in Ge

“…been monitored by spreading resistance measurements on Cu-diffused Ge samples. [7,17,18] The properties of Cu-related point defects in Ge, their interaction with other point defects, precipitation and gathering have been reviewed by Bracht. [19] Deep-Level Transient Spectroscopy (DLTS) [20] is one of the most powerful techniques to study deep levels due to its high sensitivity and resolution.…”