Methods for fabricating FET device structures are disclosed. The methods include receiving a fin of a Si based material, and converting a region of the fin into an oxide element. The oxide element exerts pressure onto the fin where a Fin-FET device is fabricated. The exerted pressure induces compressive stress in the device channel of the Fin-FET device. The methods also include receiving a rectangular member of a Si based material and converting a region of the member into an oxide element. The methods further include patterning the member that N fins are formed in parallel, while being abutted by the oxide element, which exerts pressure onto the N fins. Fin-FET devices are fabricated in the compressed fins, which results in compressively stressed device channels. FET devices structures are also disclosed. An FET devices structure has a Fin-FET device with a fin of a Si based material. An oxide element is abutting the fin and exerts pressure onto the fin. The Fin-FET device channel is compressively stressed due to the pressure on the fin. A further FET device structure has Fin-FET devices in a row each having fins. An oxide element extending perpendicularly to the row of fins is abutting the fins and exerts pressure onto the fins. Device channels of the Fin-FET devices are compressively stressed due to the pressure on the fins.