The fabrication of quantum cascade lasers emitting at 9 μm is reported. The devices operated in pulsed mode at up to 260 K. The peak powers recorded at 77 K were over 1 W and the slope efficiency η ≈ 0.5-0.6 W/A per uncoated facet. This has been achieved by the use of GaAs/ heterostructure, with the "anticrossed-diagonal" design. Double plasmon planar confinement with Al-free waveguide has been used to minimize absorption losses. The double trench lasers were fabricated using standard processing technology, i.e., wet etching and for electrical insulation. The quantum cascade laser structures have been grown by molecular beam epitaxy, with Riber Compact 21 T reactor. The stringent requirements - placed particularly on the epitaxial technology - and the influence of technological conditions on the device structure properties were presented and discussed in depth.