In this work furnace crystallization of sputtered silicon films was investigated in the temperature range from 600 to 1250 degrees C. They were characterized by XRD, TEM and ESR. The crystallization process was analyzed from the structural zone model [5], and inclusion of argon and oxygen [7]. Electrical properties of high temperatur crystallized Si-film TET with sputtered silicon dioxide were correlated to crystallization parameters, Such TFTs exhibit high level of electrical stability.