Ferroelectric capacitor and process for its manufacture

• Main Authors: Egger, Ulrich, Zhuang, Haoren, Hornik, Karl
• Format: Patent
• Language: English
• Published: 31.08.2004

The present invention relates to a method of patterning capacitors, more particularly for the fabrication of ferroelectric capacitors (FeRAMs) which find application in a number of devices including non-volatile memories and for high-k dynamic random access memories (DRAMs). Ferroelectic capacitors have the advantage that they are able to switch quickly and can be fabricated on a single VLSI chip. They also have the endurance of DRAM, the fast read/write times of SRAM and the non-volatility of flash. Forming a capacitor, by (a) forming a matrix of ferroelectric capacitor elements on a substrate, (b) forming a CAP layer over the ferroelectric capacitor elements, and (c) etching the CAP layer to a more uniform thickness. A capacitor that has a substrate layer, a matrix of ferroelectric capacitor elements including a first electrode layer substantially fixed relative to the substrate, a second electrode layer, and a ferroelectric layer sandwiched between the first and second electrode layers is disclosed. The capacitor has a shoulder layer extending from the substrate to the matrix, and a CAP layer etched to have substantially constant thickness covering sides of the matrix extending beyond the substrate.