| 摘要 |
PURPOSE:To keep a resistance value used in a circuit constant irrelevant to a temperature by a method wherein a diffusion resistance with a positive temperature coefficient and a polycrystalline silicon resistance with a negative temperature coefficient are formed in the main surface of a semiconductor and connected in series or in parallel. CONSTITUTION:After a diffusion resistance 1 is formed, a polycrystalline silicon resistance 9 are formed and connected to the diffusion resistance 1 in series through contact windows 2 with aluminum wirings 8. If the temperature coefficient of the diffusion resistance 1 is alpha (alpha>0), the temperature coefficient of the polycrystalline silicon resistance is -beta (beta>0), a reference temperature is T0, the resistance value of the diffusion resistance 1 at that time is R1, the resistance value of the polycrystalline silicon resistance 9 is R2 and the equivalent resistance value when the diffusion resistance 1 and the polycrystalline silicon resistance 9 are connected in series is R0, R0 is expressed by R0=R1+R2. If the equivalent resistance at a temperature T is R, R is expressed by R=R1+R2+(alphaR1-betaR2)(T-T0). In order to make the resistance value R constant irrelevant to the temperature, the resistance values R1 and R2 are so selected as to conform to alphaR1-betaR2=0. By designing the diffusion resistance and polycrystalline silicon resistance 9 like this, the influence of the temperature upon the resistance value can be eliminated. |
