Semiconductor device and process for forming same

A method of manufacturing a semiconductor device, comprising the steps of:

• (a) forming a gate insulator over a main surface of a semiconductor substrate;
• (b) forming a gate electrode over the gate insulator;
• (c) forming a first sidewall insulator on a sidewall of the gate electrode;
• (d) introducing a first ion into the semiconductor substrate with using the gate electrode and the first sidewall insulator as a mask, thereby forming a first diffusion layer for a source and drain in the semiconductor substrate and forming a first amorphous layer at a position apart from the gate electrode in a surface portion of the first diffusion layer;
• (e) after the step (d), forming a second sidewall insulator on the sidewall of the gate electrode and the first sidewall insulator;
• (f) introducing a second ion for forming the same conductivity type as that of the first ion into the semiconductor substrate with using the gate electrode, the first sidewall insulator and the second sidewall insulator as a mask, thereby forming a second diffusion layer for a source and drain in the semiconductor substrate and forming a second amorphous layer in a surface portion of the second diffusion layer;
• and
• (g) irradiating laser to the main surface of the semiconductor substrate, thereby selectively recrystallizing the first and second amorphous layers.

A semiconductor device having a field effect transistor, the field effect transistor comprising:

• (a) a gate insulator formed over a semiconductor substrate;
• (b) a gate electrode formed over the gate insulator;
• (c) a sidewall insulator formed on a sidewall of the gate electrode;
• (d) a diffusion layer for a source and drain formed over the semiconductor substrate so that a part of the diffusion layer is overlapped with the gate electrode when viewed from above;
• and
• (e) a first region formed in a surface portion of the diffusion layer for a source and drain so as to apart from the gate electrode, the first region being melted and liquidized in a previous time.

A semiconductor device having a field effect transistor, the field effect transistor comprising:

• (a) a gate insulator formed over a semiconductor substrate;
• (b) a gate electrode formed on the gate insulator;
• (c) a first sidewall insulator formed over a sidewall of the gate electrode;
• (d) a second sidewall insulator formed on a sidewall of the first sidewall insulator;
• (e) a first diffusion layer for a source and drain formed over the semiconductor substrate so that a part of the first diffusion layer is overlapped with the gate electrode when viewed from above;
• (f) a first region formed in a surface portion of the first diffusion layer for a source and drain so as to apart from the gate electrode, the first region being melted and liquidized in a previous time;
• (g) a second diffusion layer for a source and drain formed in the semiconductor substrate so as to have the same conductivity type as that of the first diffusion layer and to be electrically connected to the first diffusion layer;
• and
• (h) a second region formed in a surface portion of the second diffusion layer for a source and drain so as to apart from the gate electrode, the second region being melted and liquidized in a previous time.