| 摘要 |
PURPOSE:To output an end pulse at a fixed pulse width independently of the characteristics of a thin film transistor (TFT) by using a polycrystal silicone as a resistor in a signal delay means of a differential circuit and mixing impurity with the polycrystal silicone by a specific volume. CONSTITUTION:In case of using polycrystal silicone as a resistor 110, its registance value can be almost fixed by controlling the forming condition of the polycrystal silicone thin film and the dose of the impurity. The width of dispersion is <=1/5 the distortion of ON resistance of the TFT. Thereby, the signal delay time of the differential circuit can be almost uniformed and set up to a required value. For instance, about 10<14>-10<20>cm<-3> impurity is dooped in a resister 118 made of the polycrystal silicone. When about 10<20>cm<-3> boron is dooped, about 100kOMEGA/ of rhos at film thickness 1000A can be obtained. Even when solid state image pickup devices having different TFT characteristics are connected to each other, the devices can be operated without fail and rapid reading can be attained. |
