| 摘要 |
<p>PURPOSE:To enhance the reliability of a semiconductor memory device after writing by forming at least two of three directions except one direction of collector contact side in an emitter in walled structure in a collector contact nonisolation manner. CONSTITUTION:The inside of an isolating region 12 is formed in an element forming region, and two bipolar transistors Tr are formed. Each transistor Tr is of vertical type in which an emitter 5, a base 16 and a collector 17 are disposed in this order, and the collector contact 18 is common. Each transistor Tr is formed in a collector contact nonisolation structure, the base 16 and the collector contact 18 are connected directly through an epitaxial grown Si layer 10, while at least two of three directions except one of the collector contact 18 side are formed in a walled structure. Thus, the areas of right and left emitters 15 can be formed uniformly, thereby equalizing the writing current.</p> |
