| 摘要 |
PURPOSE:To enable the micronization of a device by a method wherein a sidewall is formed on the side face of an electrode, which is used as an adjusting allowance to diffuse impurity into a semiconductor substrate under a gate electrode and a threshold voltage is made controllable. CONSTITUTION:An oxide film 2 is formed on a semiconductor substrate 1 in a hot oxidizing atmosphere, a polycrystalline silicon film 3 is formed, and then impurity is diffused to make the substrate 1 an N-type. A gate electrode 4 is formed and a sidewall 5 of a silicon oxide film is formed on the side face of the electrode 4. Arsenic is diffused using the electrode 4 as a mask for the formation of an impurity diffusion layer 6 of a drain and a source. A resist mask 7 provided with an opening is formed on the electrode 4 provided with the sidewall 5. Phosphorus is implanted for the formation of an impurity diffusion layer 8 which is employed to form a depletion type MOSFET. A mask 7 is removed. By these processes, a threshold voltage can be controllable, and thus micronization of a device can be realized. |
