| 摘要 |
PURPOSE:To simplify a manufacturing process by providing a step of forming a removable auxiliary layer on a gate electrode and adjusting the energy of ion implantation for forming source and drain regions so that transmission of ions through the gate electrodes are determined by the existence of the auxiliary layer and making threshold voltages different by ion implantation. CONSTITUTION:Right under a gate electrode 2 on which an auxiliary layer 11 is not formed on a substrate 1, namely, a channel forming region 52 of a transistor T2 comprising said gate electrode 2 becomes of an opposite conductiv ity type and a channel forming region 51 of a transistor T1 comprising a gate electrode 2 on which the auxiliary layer 11 is formed is still one conductivity type. This makes the transistors T1 and T2 enhancement form and depletion form, respectively, and makes their threshold voltages different. By ion implanta tion, a source region 3 and a drain region 4 are formed, so that once of ion implantation is enough and a manufacturing process becomes simple. |
