Patent attributes
In a method of manufacturing a semiconductor device, a first gate electrode and a second gate electrode are formed in a first area and a second area of a substrate. Non-crystalline regions are formed in the first area of the substrate adjacent the first gate electrode. A layer having a first stress is formed on the substrate and the first and the second gate electrodes. A mask is formed on a first portion of the layer in the first area of the substrate to expose a second portion of the layer in the second area. The second portion is etched to form a sacrificial spacer on a sidewall of the second gate electrode. The second area of the substrate is partially etched using the mask, the second gate electrode and the sacrificial spacer, to form recesses in the second area of the substrate adjacent the second gate electrode. Patterns having a second stress are formed in the recesses.