| 摘要 |
PURPOSE:To obtain a pressure sensor having superior characteristics when a semiconductor pressure sensor is produced using an Si substrate by a method wherein the substrate is etched to provide concave parts before the electrode formation process is performed. CONSTITUTION:For an Si substrate to be used as a sensor, an N-type Si substrate 1 whose (1,1,0) face has <1,0,0> anis in the longitudinal direction to change largely the resistance value against the magnitude of expansion and contraction of the substrate, and has <1, anti 1,0> anis in the lateral direction, is used. Oxide films 3 are adhered to the both surface of the substrate 1 before the formation of electrode, openings are formed corresponding to concave parts to be formed at the back face and the back face 16 of the substrate 1 is made to be exposed. This process is performed as follows. Plural openings are formed in the films 3, but considering that side etching parts 14 are to be made by anisotropic etching, the opening areas are slightly reduced. After this process, etching is performed for about an hour using 6N-KOH liquid heated to 80 deg.C leaving the surrounding part 15 in a ring shape to form a diaphragm having plural concaves at the back face, and an appointed electrodes are sticked on the surface. |
