Two types of magnetic tunnel junctions (MTJs) with the configuration: substrate Si(100)/SiO 2 47nm/buffer/IrMn 12nm/CoFe 2.5nm/Al–O 1.5nm/NiFe 3nm/Ta 5nm and Si(100)/SiO 2 47nm/buffer/IrMn 10nm/CoFeB 3nm/MgO 2nm/CoFeB 4nm/Ta 5nm were prepared by the sputtering technique with two different buffers: A-Cu 25nm and B-Ta 5nm/Cu 25nm. The B buffer caused a high texture of MTJs whereas in the case of the A buffer junctions texture was weak. Crystallites in the textured layers grew in a columnar like shape that induced interfacial roughness. High textured buffer B caused high interfacial roughness that reduced the resistance-area (RA) product due to a barrier thickness fluctuation. RA also changed substantially depending on the type of a barrier. The highest RA product ∼15MΩμm 2 was achieved for a low textured junction with Al–O barrier whereas in the high textured MgO sample RA product was ∼100kΩμm 2 . Tunnel magnetoresistance (TMR) measured at room temperature was about 45% for the samples with Al–O barrier, whereas for the samples with MgO barrier TMR was about three times higher and achieved 140%.