Memory circuit

• US 20030035338A1
• Filed: 07/26/2002
• Published: 02/20/2003
• Est. Priority Date: 08/17/2001
• Status: Active Grant

• Current Assignee: III Holdings 6, LLC
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Battersby, Stephen J.
• Granted Patent: US 6,639,821 B2
• Time in Patent Office: Days
• US Class Current: 365/230.06
• CPC Class Codes: G11C 8/08 Word line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, for word lines

Abstract

A memory device comprises an array of memory elements (15) overlying driver cells (3). Vias (21) connect the driver cells (3) to the memory elements (15). The vias are distributed over the area of the array to connect the driver cells (3) to the row and column conductors (9, 13) of the memory array.

Claims

1. A memory device comprising:

a substrate extending in a plane;

an array of memory elements arranged in a plurality of rows and a plurality of columns arranged substantially parallel to the plane of the substrate and over a predetermined area of the substrate;

a plurality of row conductors extending along the rows of memory elements and connecting to the memory elements of the respective rows;

a plurality of column conductors extending along the columns of memory elements and connecting to the memory elements of the respective columns;

a plurality of driver cells containing drivers for driving the row and/or column conductors, arranged in a layer between the memory array and the substrate, and

an insulating layer between the driver cells and the array of memory cells, a plurality of conductors passing through the insulating layer distributed over the predetermined area connecting the driver cells to corresponding row or column conductors.

2. A memory device according to claim 1 wherein the plurality of driver cells are arranged in a regular driver cell array extending across the predetermined area of the substrate.

3. A memory device according to claim 2 wherein the driver cells are arranged in a plurality of rows and columns parallel to the rows and columns respectively of memory cells and each column of driver cells underlies a number of column conductors and the drivers in each column of driver cells is connected to a different one of the number of column conductors which the column of driver cells underlies.

4. A memory device according to any preceding claim wherein the row drivers are arranged around the outside of the memory array.

5. A memory device according to any preceding claim including a stack of arrays of memory elements, each array layer including a plurality of rows and a plurality of columns of memory elements arranged substantially parallel to the plane of the substrate, connected by row conductors and column conductors.

6. A memory device according to claim 5 wherein each column driver drives exactly one column conductor in one of the stack of arrays of memory elements.

7. A memory device according to claim 6 wherein at least one array of memory elements has gaps where no memory elements are defined and wherein vias pass through the gaps to connect the drivers on one side of the said at least one array of memory elements to a further array of memory elements on the opposite side of the said at least one array of memory elements.

8. A memory device according to any of claims 5 to 7 wherein each row driver drives a row in each of the stack of arrays of memory elements.

9. A memory device according to any of claims 5 to 7 wherein each row driver drives a row in a single one of the stack of arrays of memory elements.

10. A method of manufacturing a memory device on a substrate extending in a plane, including

defining an array of driver cells including at least column drivers over the substrate;

depositing an insulating layer over the array of driver cells;

depositing a plurality of column conductors over the insulating layer;

defining an array of memory elements arranged in a plurality of rows and a plurality of columns substantially over the array of driver cells; and

depositing a plurality of row conductors.