Physical properties of optimization and control of nitride superconducting thin films for superconducting device applications

为了找到制备高质量NbTiN薄膜的最佳工艺条件，我们研究了在不同衬底上不同沉积条件下NbTiN薄膜的超导性能与晶体结构的关系，发现薄膜的超导性能与晶格常数有关。我们在MgO（100）衬底上生长了高质量的NbN/AlN/NbN三层外延层，研制了NbN基SFQ电路。我们成功地证明了所有设计的SFQ单元的正确操作。

In order to find the optimum condition for fabrication of high-quality NbTiN thin films, we investigated the relationship between superconducting properties and crystal structure for the NbTiN thin films deposited on various substrates under different depositing conditions.It is found that the superconducting properties of the films depend on the lattice constntNext,we developed NbN-based SFQ circuits consisting of high-quality epitaxial NbN/AlN/NbN trilayer grown on MgO (100) substrate. We succeeded in demonstrating correct operations of all the designed SFQ cells.