  We have developped a novel lift-off process for fabrication of high quality
superconducting submicron niobium structures. The process makes use of a
thermostable polymer with a high transition temperature T_{g}= 235 C and an
excellent chemical stability. The superconducting critical temperature of 100
nm wide niobium lines is above 7 K. An example of shadow evaporation of a Nb-Cu
submicron hybrid structure is given. A potential application of this process is
the fabrication of very small single electron devices using refratory metals.
