Fabrication of thin-film-type Bi₂Sr₂CaCu₂O_8+δintrinsic Josephson junctions by pulsed-laser-deposition

Abstract

Intrinsic Josephson junctions were fabricated on Bi2Sr2CaCu2O8+δ thin films. The thin films were prepared by a pulsed-laser-deposition technique at the substrate temperature of 500 °C. The deposited films were annealed at 884–890 °C for crystallization. Bi2Sr2CaCu2O8+δ thin films were successfully obtained with the stoichiometric composition. At the annealing temperature of 888 °C, a film consisting of large crystalline grains has been obtained; a flat terrace area reaches several tens of µm and is larger than the typical mesa size for the intrinsic Josephson junction. The mesa structure patterned on the annealed film has exhibited clear multiple branches in the current–voltage characteristic peculiar to the intrinsic Josephson junctions.

The effects of the post-annealing time on the growth mechanism of Bi2Sr2Ca1Cu2O8+∂ thin films produced on MgO (100) single crystal substrates by pulsed laser deposition (PLD)

“…Single crystal of MgO is the most preferred material for producing Bi-2212 thin films because of its low-cost, compatible features such as dielectric constant, stable structure and chemical stability [13][14][15][16][17][18]. Recently, it was reported that a significant improvement in superconducting properties of thin films could be obtained by PLD and the application of post-annealing heat treatment in an atmosphere containing a mixture of argon and oxygen (Ar:93,O 2 :7) [15,16,19,20]. Among various factors, the quality of substrate also affects directly the superconducting properties of thin films.…”

The effects of the post-annealing temperature on the growth mechanism of Bi2Sr2Ca1Cu2O8+ thin films produced on MgO (1 0 0) single crystal substrates by pulsed laser deposition (PLD)

“…Superconducting electronics devices require having high quality thin films, with high T C values and very smooth surfaces as well as in single crystalline form. In particular, the use of high quality high-T C thin films is important for device applications like SQUIDs [22,25], THz radiation sources [26], bolometers [23], intrinsic Josephson junctions [17,27], and other cryo-electronic devices.…”

“…It has been recently reported, for example, that high T C and J C values may be obtained for these high-T C materials produced by continuous laser irradiation methods [40][41][42]. On the other hand, it was reported that a significant improvement in supercon ducting propertie s of the thin films could be obtained, deposited by PLD and applying a post-anneal ing heat treatment in an atmosph ere containing a mixture of argon and oxygen (Ar: 93, O 2 : 7) [9,13,15,17]. Among various factors, the quality of the substrate also affects directly the supercon ducting properties of the thin films.…”

High-T c Josephson junctions

“…Schmidl et al (1995), Haruta et al (2009) and references therein. Thin film structures used a mesa-type geometry whereas the high-T c film is patterned with lateral dimensions in the µm range, e.g.…”