ONE-TIME UV-PROGRAMMABLE NON-VOLATILE SEMICONDUCTOR MEMORY AND METHOD OF PROGRAMMING SUCH A SEMICONDUCTOR MEMORY

摘要

One-time UV-programmable read-only memory (1) comprising a number of memory cells in the form of MOS transistors (T) which are arranged in a matrix of rows and columns, each transistor comprising a source and a drain zone (12) and a channel zone (13) formed in a surface zone (11) of a semiconductor substrate (10). Said semiconductor zones adjoin a surface (14) of the semiconductor substrate on which surface a layer structure (17) is formed comprising floating gates (15) and control gates (16). The layer structure is provided with windows (18) through which UV radiation can reach the edges of the floating gates. The memory is further provided with means for generating an electric voltage between the substrate (10) and the control gates (16) during programming the memory by means of UV radiation. Thus, the memory can be programmed without being externally contacted during programming.