| 摘要 |
PURPOSE:To obtain an FET which has excellent characteristic for reducing the resistances of source and drain regions without deterioration of gate withstand voltage by forming by an impurity ion implantation the source and drain regions with a gate electrode using Al-Si alloy as a mask. CONSTITUTION:After a silicon thin film 2 is accumulated on a glass substrate 1, an SiO2 film 3 is covered, a gate electrode 4 which is made of Al-Si alloy (Si 1.2wt%) is formed, and impurity ion implantation 5 is performed in a source region 6 and a drain region 7 with the electrode 4 as a mask. The electrode 4 exhibits extremely good mask effect for an ion beam 5. After a heat treatment, a source electrode 8 and a drain electrode 9 are formed, and an FET is completed. Even if the FET which uses as the gate electrode Al-Si alloy is heat treated at 550 deg.C for longer than 20hr after ion implantation, the gate withstand voltage is not deteriorated, or no phenomenon of shortcircuiting between gate channels occurs. The Si content of the alloy is preferably 0.5-2wt%. |
