SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURE

摘要

A semiconductor device 10 is manufactured using a Silicon (Si) On Insulator (SOI) wafer 11. The SOI wafer 11 has an upper layer 12 and lower layer 13 of Si crystal separated by a barrier layer 14 Silicon Oxide (SiO2). A gate stack 15 is formed on an upper surface 19 of the wafer 11. Source- drain extension regions are formed in the upper Si layer 12 of the wafer 11 on opposing sides of the gate stack 15 by implanting dopant Boron (B) ions in regions 18 shallow under the upper surface 19 of the wafer 11 , in the upper Si layer 12 of the wafer 11. The dopant B ions are implanted at energy less than around 5 keV and to a dose between around 5 x 1013 cm"2 and 2 x 1015 cm'2. This achieves a dopant B atom concentration having a peak concentration of around 1021 cm"3. Either before or after the dopant B ions are implanted, vacancies are generated in vacancy regions 17 in the upper Si layer 12 of the wafer 11 by implanting vacancy generating Si ions into the wafer 11. This can maximise the electrical activation of the dopant B ions after annealing.