Method of fabricating metal oxide semiconductor transistor

A method of fabricating a CMOS transistor, comprising:

• providing a semiconductor substrate having at least a first conductive transistor area for fabricating first conductive transistors and at least a second conductive transistor area for fabricating second conductive transistors, and an isolation structure between the first conductive transistor area and the second conductive transistor area;
• forming a gate on the first conductive transistor area and on the second conductive transistor area respectively;
• forming a first protective layer on the semiconductor substrate, and the first protective layer covering the surface of each gate;
• forming at least a first recess within the semiconductor substrate adjacent to the gate in the first conductive transistor area;
• forming a first epitaxial layer in the first recess, wherein the top surface of the first epitaxial layer is above the surface of the semiconductor substrate;
• and
• forming a spacer on the sidewall of each gate and at least on a portion of the first epitaxial layer, wherein a contact surface of the first epitaxial layer and the spacer is above the surface of the semiconductor substrate.