| 摘要 |
PURPOSE:To form many sensor chips having excellent dimensional accuracy on one wafer by processing a silicon base from other surface, forming a recess and part of the same depth as that of recess of a through hole, and then processing it from one surface to form a residual part of the hole. CONSTITUTION:A piezoresistance 4, etc., is formed on one surface layer of a silicon substrate 10. Then, oxide films 12 are formed on both side surfaces. Thereafter, a contact hole, a through hole with a nitride film 8 are formed on upper surfaces of the films 12, openings 31-33 are formed at bonded parts to a glass cap, and part except position opposed to a part to become a weight on a lower surface is opened. Openings 34, 35 for forming a recess and a through hole are formed on the lower surface, and the opening 33 of the upper surface is covered with a resist film 13. Then, a recess 22 and a lower part 25 of the through hole are formed. Thereafter, the substrate 10 and the film 8 are processed from an upper surface, and an upper part 23 of the through hole and a contact hole 24 are formed. Subsequently, a sectional surface 14 is diced to chips. |
