In an embodiment, the thermal treatment 233 is a millisecond annealing (MSA) process. In some embodiments, the MSA process utilizes a laser anneal process to achieve the annealing times in the range of milliseconds. Performing annealing process on millisecond scale can be advantageous because such extremely short annealing treatment can activate the dopants (e.g., first and second species) in the source/drain regions 292 with minimized diffusion of the dopants from the source/drain regions 292 even at high annealing temperature (e.g., 850° C. or above). Since the dopants in the source/drain regions 292 are activated with minimal diffusion, short channel effect can be prevented. An example chamber for performing the laser anneal process is Astra DSA? chamber available from Applied Materials, Inc. of Santa Clara, Calif. It is contemplated that a flash lamp annealing process or any advanced process using suitable optical radiation for performing an anneal for a very short amount of time, e.g., on a millisecond time scale, may also be used.