Programmable semiconductor device with high breakdown voltage and high-density programmable semiconductor memory having such a semiconductor device

• Main Author: VAN DORT; MAARTEN J
• Format: Patent
• Language: English
• Published: 01.10.1996
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A programmable semiconductor memory with filament or point diodes in the intersections of a matrix system can be manufactured with minimum dimensions and thus with a very high density owing to the absence of alignment tolerances. A possible problem is then posed by the strong leakage currents which may arise during programming owing to punch-through between adjoining diodes. Decreasing the leakage current through the use of a higher background concentration of the region in which these diodes are formed is not possible because this reduces the breakdown voltage of the pn junctions of the diodes too much. According to the invention, a more strongly doped surface zone is provided in the region between the diodes, which zone is situated at least at a distance from the diode points. In a specific embodiment, the zone extends less deeply into the region than do the diodes. The invention is based on the recognition that the breakdown voltage is determined by the location where the curvature of the diode is strongest. The zone suppresses the leakage current to a high degree, while the breakdown voltage of the diodes remains sufficiently high.