Method of programming a 3D RRAM
View Patent ↗A memory array layer for use in a 3D RRAM is formed, with peripheral circuitry, on a silicon substrate; layers of silicon oxide, bottom electrode material, silicon oxide, resistor material, silicon oxide, silicon nitride, silicon oxide, top electrode and covering oxide are deposited and formed. Multiple memory array layers may be formed on top of one another. The RRAM of the invention may be programmed in a single step or a two step programming process.
1. A method of programming a 3D RRAM comprising:
selecting a memory cell to be written to;
applying a high voltage programming pulse to a first related bit line;
applying a low voltage programming pulse to a second related bit line;
floating the associated word line;
Biasing all other word lines with half-programming pulse voltages; and
biasing all non-selected bit lines to the ground potential.
2. The method of claim 1 wherein reading a memory cell includes
applying a small voltage to the word lines of the non-selected bits to enhance the line voltage difference between the first related bit line and the second related bit line; and
applying a read voltage to the word line associated with the selected memory cell and detecting the voltage difference between the first related bit line and the second related bit line.
3. The method of claim 1 wherein reading a memory cell includes
applying a small voltage to the non-selected word lines to enhance the line voltage difference between the first related bit line and the second related bit line; and
applying a read voltage to the word line associated with the selected memory cell and detecting the voltage difference between the first related bit line and the second related bit line.
4. A method of programming a 3D RRAM comprising:
selecting a memory cell to be written to;
applying a low voltage programming pulse to a first memory resistor in the memory cell;
applying a high voltage programming pulse to a second memory resistor in the memory cell;
setting the selected word line to ground potential;
biasing all other word lines are biased to 0.5 V P ;
biasing a first related bit line with a negative programming pulse, having a pulse amplitude of −V P ;
biasing a second related bit line with a positive programming pulse, having amplitude of +V P ; and
pulsing all non-selected memory resistors with a programming voltage of between 0V P and 0.5 V P .