Patent ID: 7420202

Claim:
An electronic device comprising: a first transistor structure of a first conductivity type including a first active region having a first edge and a second edge, wherein: the first edge has a length that extends substantially along a channel length direction of the first transistor structure; and the second edge has a length that extends substantially along a channel width direction of the first transistor structure; a field isolation region adjacent to the first active region; and a layer of a first stress type larger than the first active region overlying the field isolation region, wherein from a top view: the layer is not part of a sidewall spacer structure for the first transistor structure; a first edge of the layer lies adjacent to the first edge of the first active region; a second edge of the layer lies adjacent to the second edge of the first active region; a first distance is a distance between the first edge of the first active region and the first edge of the layer; a second distance is a distance between the second edge of the first active region and the second edge of the layer; and the first distance is less than the second distance.