| 摘要 |
PURPOSE:To adjust the resistance value of a resistor to a resistance value, which is needed, by a method wherein a decrease or a increase of the resistance value is performed by that impurities of the same conductive type as that of impurities dopped the polycrystalline silicon resistor are further diffused in the resistor by performing a laser heating and the resistance value thereof is made to decrease, or, that impurities of the opposite conductive type are diffused in the resistor and the resistance value thereof is made to increase. CONSTITUTION:A polycrystalline silicon resistor 11, wherein impurities of an N type conductive type have been dopped, is formed on an Si substrate 1 through an SiO2 film 2 and both ends thereof are connected to other elements through Al wirings 12A and 12B. A polycrystalline silicon layer 14, wherein impurities of a P type conductive type have been dopped in a high concentration, is insularly formed on the polycrystalline silicon resistor 11 through an SiO2 film 13, and an SiO2 film 15, a phosphoric glass layer 16 and an SiO2 layer or an Si3N4 layer, or, a final passivation film 17 consisting of both of the SiO2 layer and the Si3N4 layer are formed thereon. Then, the phosphoric glass film 16 is irradiated with a laser beam through the SiO2 films 13 and 15, while the resistance value existing in a 10mum long part of the film 16 is being measured, and the irradiation is stopped at a point when a prescribed resistance value has been obtained, thereby enabling to adjust the resistance value to an arbitrary resistance value. |
