| 摘要 |
PURPOSE:To enhance the quality of a semiconductor device of three-dimensional structure by diffusing or implanting boron having large diffusion coefficient to form a semiconductor element for forming source, drain regions in the uppermost layer. CONSTITUTION:Since n-channel semiconductor elements are formed in second and third semiconductor crystal layers II, III, source, drain regions are formed in n-type regions by diffusing or implanting boron. Since a p-channel semiconductor element is formed in a fourth semiconductor crystal layer iv, source, drain regions are formed in p-type regions by diffusing or implanting boron. Thus, the layer iv is diffused or implanted with boron having large diffusion coefficient, the the layers II, III are diffused or implanted with boron having small diffusion coefficient. Accordingly, a region having the region diffused or implanted with the boron including large diffusion coefficient is reduced in its heat treatment to decrease the quantity of an impurity to be diffused through grain boundary as a hole. |
