JPS6482674A - Thin film transistor - Google Patents

Abstract

PURPOSE:To reduce a capacity component generated between a gate electrode and a source electrode and to improve an S/N ratio by reducing the area of the superposing region of the gate electrode and the source electrode. CONSTITUTION:In a thin film transistor 19, its source electrode 15 is formed to be smaller than its drain region 16, and the superposing area of the electrode 15 and a gate electrode 12 is extremely smaller than that of the drain and gate electrodes 16 and 12. Accordingly, a gate-source capacity CGS presented between the electrodes 12 and 15 is extremely small. If an equivalent capacity CLC between the opposite electrodes facing through a pixel electrode 18 and a liquid crystal is 0.1PF, the voltage drop V of the source electrode is extremely small. Accordingly, the electrode 18 can be miniaturized. Since the electrode 16 is so formed as to surround the electrode 15, its substantial channel width can be increased, thereby providing large driving capacity of the thin film transistor.