OUTPUT BUFFER AND PROTECTIVE CIRCUIT; SEMICONDUCTOR STORAGE DEVICE CONTAINING THEM; ITS TYPE DEVELOPMENT, LAYOUT SYSTEM AND TEST SYSTEM

摘要

PURPOSE:To efficiently develop types of a semiconductor storage device by a method wherein a common semiconductor substrate provided with the following is prepared and is owned jointly by a plurality of package specifications: a plurality of bonding pads arranged in optimum positions according to individual package shapes; a bonding pad, for control, which makes selectively effective a plurality of buffers corresponding to the pads and the plurality of bonding pads. CONSTITUTION:On a common semiconductor substrate of a dynamic RAM, names of pads used in the dynamic RAM according to DIP and SOJ package specifications are mentioned at the inside of a dotted line; names of pads used in the dynamic RAM according to ZIP package specifications are mentioned at its outside. This dynamic RAM is classified into a total of 21 product types according to its bit constitution, its operating mode and its package shape. Accordingly, when a semiconductor substrate which is common to all of the 21 product types is prepared and one part of its photomask is changed or a bonding treatment is executed selectively on a prescribed pad, either of the product types can be realized in a alternative way.