Vertically stacked field programmable nonvolatile memory and method of fabrication
First Claim
Patent Images
1. A memory cell comprising:
- a first conductor having a first width;
a second conductor having a second width;
a steering element for providing enhanced current flow in one direction through the steering element having a first end surface with first opposite edges spaced-apart by a distance equal to the first width and second opposite edges spaced-apart by a distance equal to the second width where the first opposite edges are aligned with the first conductor and where the first end surface is in continuous contact with the first conductor;
a state change element for retaining a programmed state, connected in series with the steering element having a second end surface with third opposite edges spaced-apart by a distance equal to the first width and fourth opposite edges spaced-apart by a distance equal to the second width where the fourth opposite edges are aligned with the second conductor and where the second end surface is in continuous contact with the second conductor, and;
the steering element and state change element being vertically aligned with one another.
13 Assignments
0 Petitions
Accused Products
Abstract
A very high density field programmable memory is disclosed. An array is formed vertically above a substrate using several layers, each layer of which includes vertically fabricated memory cells. The cell in an N level array may be formed with N+1 masking steps plus masking steps needed for contacts. Maximum use of self alignment techniques minimizes photolithographic limitations. In one embodiment the peripheral circuits are formed in a silicon substrate and an N level array is fabricated above the substrate.
1811 Citations
38 Claims
-
1. A memory cell comprising:
-
a first conductor having a first width; a second conductor having a second width; a steering element for providing enhanced current flow in one direction through the steering element having a first end surface with first opposite edges spaced-apart by a distance equal to the first width and second opposite edges spaced-apart by a distance equal to the second width where the first opposite edges are aligned with the first conductor and where the first end surface is in continuous contact with the first conductor; a state change element for retaining a programmed state, connected in series with the steering element having a second end surface with third opposite edges spaced-apart by a distance equal to the first width and fourth opposite edges spaced-apart by a distance equal to the second width where the fourth opposite edges are aligned with the second conductor and where the second end surface is in continuous contact with the second conductor, and; the steering element and state change element being vertically aligned with one another. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 35, 36)
-
-
28. A memory cell comprising:
-
a first conductor; a second conductor; a pillar having a generally rectangular first and second opposite end surface each with first and second spaced-apart edges and having a steering element terminating at the first end surface which more readily conducts current in one direction, and a state change element terminating at the second end surface, the state change element for recording a state; the first spaced-apart edges at the first end surface being aligned with the first conductor with the first end surface being in continuous contact with the first conductor, the second spaced-apart edges at the second end surface being aligned with the second conductor with the second end surface being in continuous contact with the second conductor. - View Dependent Claims (29, 30, 31, 32, 33, 34, 37, 38)
-
Specification