| 摘要 |
PURPOSE:To restrain the energy fluctuation of light reflected from the lower layer of a thin film resistor, by making the laser light for adjusting the resistance value of a thin film resistor have a wavelength range larger than or equal to a specific value from the center wavelength of the laser light. CONSTITUTION:In this laser trimming method, the resistance value of a thin film resistor 3 in a semiconductor device in which a lower layer film 6 and the thin film resistor 3 are formed in order on a substrate 7 is adjusted. The laser light having a center wavelength lambda is made to have wavelength width of DELTAlambda>=lambda<2>/K.nd where (d) is the thickness of the lower layer film 6 of the thin film resistor, (n) is the refractive index of the film 6, and K is an arbitrary constant which is determined by the degree of influence of the lower layer film 6 upon the absorption ratio of laser light energy of the thin film resistor 3. Thereby the fluctuation of energy of the reflected light from the interface under the lower layer film 6 caused by the laser light penetrating the thin film resistor 3 and the lower layer film 6 is restrained. |
