Interdiffusion and interfacial reaction between an YBa2Cu3Ox thin film and substrates

Abstract

Interdiffusion and interfacial reaction between a sputter-deposited YBa2Cu3Ox thin film and substrates (MgO, sapphire, quartz, and Si) have been investigated by 2.7 MeV 4He+ Rutherford backscattering spectrometry. The diffusivities of Cu in the substrates and of the substrate elements (Mg, Al, and Si) in the Y-Ba-Cu-O thin films have been determined over the annealing temperature range from 876 to 1226 K in an oxygen atmosphere. Among three metallic elements of Y, Ba, and Cu, Cu diffuses the fastest into the substrates. Copper silicide is observed in the interfacial region between the film and the Si substrate. Among these substrates, MgO is suggested to be the most stable on annealing.

Determination of Ca diffusion in YBCO films by Secondary Ion Mass Spectroscopy

“…2a). Cu diffusion from YBCO into the film substrate has been previously reported by Nakajima et al [28] on Cu diffusion into single crystal MgO. The diffusional profile which corresponds to the raw data shown in Fig.…”

Buffer layers for superconducting YBaCuO thin films on silicon and SiO2

“…Post annealing at 800 °C of amorphous and insulating 123 films on silicon yields heavily reacted samples, as reported in the literature [23,24]. Nakajima et al [24] reported the formation of copper silicide.…”

“…Nakajima et al [24] reported the formation of copper silicide. In a powder mixture of silicon and the superconducting 123 phase, the 211 Y-Ba-Cu-O phase was observed primarily after annealing between 600 and 800 °C in an oxygen flow by Cheung and Ruckenstein [25].…”

“…Although single-crystal MgO and ZrO 2 are both successful substrates and have been proven to be very inert in contact with 123 [24,25], it was possible to grow crystalline 123 on thin film ZrO 2, whereas a thin layer of polycrystalline MgO was not able to prevent diffusion of barium into the underlying SiO 2. The NiSi/ in the Si/NiSi2/ZrO2/123 samples did not participate in any reaction.…”

In situ superconducting Y−Ba−Cu−O thin films by single-target r.f. magnetron sputtering

“…SrTi03, MgO, YZS) (see for example [6] and references therein). This is mainly due to the interdiffusion between film and sapphire [15], which takes place at high temperatures, and to the mismatch of the lattice parameters of Y-Ba-Cu-O and A1203.…”