Selective STI stress relaxation through ion implantation

A device comprising:

• a substrate comprising a device region and a trench surrounding the device region;
• a stress layer lining the sidewalls and bottom of the first trench, the stress layer comprising a stress material with a first stress;
• and
• stress relaxing ions disposed in the stress layer, the stress relaxing ions relaxes the first stress of the stress material to result in the stress layer having a first relaxed stress, the stress relaxing ions result in the stress layer which is resistant to stress increases from anneals.

A device comprising:

• a substrate comprising a first device region and a first trench surrounding the first device region in about a first and a second direction, the first trench comprises first and second opposing sidewalls surrounding the first device region, the first direction is about parallel to a first channel direction of a first transistor in the device region and the second direction is about parallel to a second channel direction of the first region, the first and second channel directions are perpendicular with respect to each other;
• a stress layer lining the sidewalls and bottom of the first trench, the stress layer comprising a stress material with a first stress, the stress layer includes first and second portions lining the sidewalls and bottom of the trench, wherein
• the first portion of the stress layer lines the opposing sidewalls and bottom of the trench in the first direction, the first portion has the first stress, and
• the second portion of the stress layer lines the opposing sidewalls and bottom of the trench in the second direction, the second portion contains stress relaxing ions, the stress relaxing ions relaxes the first stress of the stress material to result in the second portion of the stress layer having a first relaxed stress, the stress relaxing ions result in the second portion which is resistant to stress increases from anneals.