| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device equipped with an SON structure having a thick cavity inside a semiconductor substrate, and to provide a semiconductor device.SOLUTION: A semiconductor device manufacturing method comprises: forming two and more trenches 2 on a surface of a silicon substrate 1 in a manner such that each has a cross-sectional shape where a part 2c near an intermediate part at a depth between an upper end 2a and a bottom 2b swells outward; subsequently generating surface migration of silicon atoms on the surface of the silicon substrate 1 by high temperature annealing to block the upper ends 2a of the trenches 2 thereby to form a plurality of cavities composed of the trenches 2 inside the silicon substrate 1; and further continuing high temperature annealing to form one cavity part 3 in which the plurality of cavities are integrated. A second open width x2 of the part 2c near the intermediate part of the trench 2 is 1.1-1.5 times a first width x1 of the upper end 2a of the trench 2. An aspect ratio of the trench 2 is 8 and over. |
