SEMICONDUCTOR DEVICE, METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE AND COMMUNICATION METHOD

摘要

A channel region (2), a source region (3) and a drain region (4) are formed on a polycrystalline semiconductor layer (1). The characteristic of a polycrystalline TFT (101) is dispersed by the amount of crystal grain boundaries (6) contained in the channel region (2). A drain current is reduced as the amount of the crystal grain boundaries (6) contained in the channel region (2) is increased. In order to utilize a code obtained by encoding the electric characteristic of the TFT (101) for identification of a semiconductor chip, a system or the like, the TFT (101) is mounted on the semiconductor chip, the system or the like along with an encoder circuit. Thus, a barrier against illegal use of a user terminal is improved at a low cost.