| 摘要 |
<p>In order to provide a passive electro-optical display medium in a matrix display device with a sufficiently steep threshold with respect to the applied voltage and having a memory, a switching element (9) is placed in series having each picture element. The switching element (9) is provided between a picture electrode (6) of each picture element and a driving electrode (8). The switching element (9) is formed by a polysilicon island (20) in which n+-doped regions (22,23) are provided which are separated by a p-doped region (21). As a result of this, two series-arranged, oppositely directed p-n junctions are formed of which one is always reverse biased. The width of the p-doped regions is so small that punch-through occurs between the two p-n junctions before one of the p-n junctions breaks down. Due to the occurrence of punch-through, the series resistance of the switching element is negligibly small so that a favorable RON/ROFF ratio is obtained and the picture elements can be driven with comparatively low voltages.</p> |
