International Business Machines Corporation
HETEROJUNCTION THIN FILM DIODE

Abstract:

A diode is made of a p-type layer and an n-type layer connected in series between a bottom and top electrode. The p-type and n-type layers have a thickness below 20 nm. A p-type dopant concentration and an n-type dopant concentration are high enough to keep a total resistance across the diode at less than 250.OMEGA. when the diode is forward biased while still retaining the characteristics of a diode. In some embodiments, the ratio of an ON current to an OFF current is greater than 2.5.times.10.sup.4. Alternate embodiments of the diode, arrays of diodes and methods of making diodes are disclosed. Example arrays include memory arrays using diodes and phase change memories (PCMs) connected in series as array elements. The arrays can be stacked in layers and can be made/embodied in the back-end-of-the line (BEOL).