Three-dimensional vertical one-time-programmable memory
View Patent ↗The present invention discloses a three-dimensional vertical one-time-programmable memory (3D-OTP V ). It comprises a plurality of vertical OTP strings formed side-by-side on a substrate circuit. Each OTP string comprises a plurality of vertically stacked OTP cells. Each OTP cell comprises an antifuse layer. The horizontal address lines and the vertical address lines comprise oppositely-doped semiconductor materials.
1. A three-dimensional vertical one-time-programmable memory (3D-OTP V ), comprising:
a semiconductor substrate comprising a substrate circuit;
a plurality of vertically stacked horizontal address lines above said semiconductor circuit, said horizontal address lines comprising at least a first semiconductor material;
a plurality of memory holes through said horizontal address lines;
an antifuse layer formed on the sidewalls of said memory holes, wherein said antifuse layer is irreversibly switched from a high-resistance state to a low-resistance state during programming;
a plurality of vertical address line in said memory holes, said vertical address lines comprising at least a second semiconductor material;
a plurality of OTP cells at the intersections of said horizontal address lines and said vertical address lines;
wherein said first and second semiconductor materials are oppositely doped.
2. The 3D-OTP V according to claim 1 , wherein each of said OTP cells further comprises a quasi-conductive layer.
3. The 3D-OTP V according to claim 2 , wherein the resistance of said quasi-conductive layer at the read voltage is substantially lower than when the applied voltage has a magnitude smaller than or polarity opposite to that of the read voltage.
4. The 3D-OTP V according to claim 1 , wherein all OTP cells coupled to selected one of said horizontal address lines are read out in a single read cycle.
5. The 3D-OTP V according to claim 1 , wherein said plurality of OTP cells form a vertical OTP string.
6. The 3D-OTP V according to claim 2 , further comprising a vertical transistor coupled to said OTP string.
7. The 3D-OTP V according to claim 6 , wherein said vertical transistor is formed in a first portion of said memory hole, and said OTP string is formed in a second portion of said memory hole.
8. The 3D-OTP V according to claim 1 , wherein said OTP cells have more than two states, the OTP cells in different states having different resistance value.