中文摘要：

本文报导了利用混合物理化学气相沉积法（Hybrid physical-chemical vapor deposition,HPCVD）在SiC（0001）衬底上制备干净的MgB2超薄膜.在背景气体压强、载气H2流量等条件一定的情况下,改变B2H6流量及沉积时间,制备不同厚度的MgB2超薄膜样品,并研究了超导转变温度Tc、剩余电阻率ρ（42K）、上临界场Hc2等与膜厚的关系.这系列超薄膜生长沿c轴外延,随膜厚度的变小Tc（0）降低,ρ（42K）升高.膜在衬底上的生长遵循Volmer-Weber岛状生长模式.对于10nm厚的膜,Tc032.4K,ρ42K124.92μΩ·cm,其表面连接性良好,平均粗糙度为2.72nm,上临界磁场Hc20K12T,零场4K时的临界电流密度Jc107A/cm2,为迄今为止所观测到的10nm厚MgB2超薄膜的最高Jc值,这也证明了10nm厚的MgB2膜在超导纳米器件上具有很强的应用潜力.

英文摘要：

We fabricated MgB2 ultra-thin films via hybrid physical-chemical vapor deposition （HPCVD） technique. Under the same background pressure,the same H2 flow rate,by changing B2H6 flow rate and deposition time,we made a series of ultra-thin films,thickness ranging from 5nm to 80nm. These films grew on SiC substrate,all c-axis epitaxial. The film formation obeys the Volmer-Weber mode. As the thickness increases,critical transition temperature Tc（0） also increases,the residual resistivity decreases. Especially,a very high Tc（0） 32.4K,low residual resistivity ρ42K124.92μΩ·cm,and extremely high critical current density Jc107A/cm2 （0T,4K）,upper critical field Hc2（0） for 10nm film was reported. Moreover,the smooth surface of the epitaxial films,with root-mean-square （RMS） roughness2.72nm,makes them well qualified for device applications.